Science.gov

Sample records for plasmon resonance methodology

  1. Nanowire Plasmon Resonators

    NASA Astrophysics Data System (ADS)

    de Leon, Nathalie; Shields, Brendan; Yu, Chun; Englund, Dirk; Akimov, Alexey; Lukin, Mikhail; Park, Hongkun

    2011-05-01

    Strong interactions between light and matter can be engineered by confining light to a small volume for an extended period of time. Nanoscale plasmonic structures can concentrate lighte well below the diffraction limit, but realization of small mode-volume plasmon cavities remains an outstanding challenge. We propose and demonstrate a new approach for realization of nanoscale plasmon resonators enabling strong light-matter interaction. In our approach, chemically synthesized silver nanowires are surrounded by patterned dielectric to create resonators with mode volumes that are two orders of magnitude below the diffraction limit and quality factors approaching 100. We show that they can be used to enhance spontaneous emission rates of CdSe quantum dots and single diamond nitrogen-vacancy centers by a factor larger than 20 at the cavity resonance.

  2. Surface plasmon resonance methodology for monitoring polymerization kinetics and morphology changes of brushes-evaluated with poly(N-isopropylacrylamide)

    NASA Astrophysics Data System (ADS)

    Emilsson, Gustav; Schoch, Rafael L.; Oertle, Philipp; Xiong, Kunli; Lim, Roderick Y. H.; Dahlin, Andreas B.

    2017-02-01

    Polymerization from surfaces and the resulting "brushes" have many uses in the development of novel materials and functional interfaces. However, it is difficult to accurately monitor the polymerization rate, which limits the use of polymer brushes in applications where control of thickness is desirable. We present a new methodology based on angular surface plasmon resonance (SPR) which provides real-time measurements of the thickness evolution during atom transfer radical polymerization, using poly(N-isopropylacrylamide) as an example. Our data analysis shows that the growth is linear with a rate of ∼20 nm/min in a water/methanol mixture up to ∼100 nm after which chain termination gradually reduces the growth rate. Further, we introduce an improved method in SPR which makes it possible to determine changes in brush height and refractive index during switching of responsive polymers. The ratio between heights in the coil to globule transition at 32 °C in water was found to be almost 5, independent of the initial absolute height up to ∼200 nm, in agreement with theory. Complementary quartz crystal microbalance and atomic force microscopy data confirm the accuracy of our results. With the methodology presented here the established SPR technique can be used for quantitative characterization of surface-initiated polymerization and responsive polymer brushes.

  3. Ellipsometric surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Hsu, Wei-Liang; Lee, Shu-Sheng; Lee, Chih-Kung

    2009-03-01

    We develop a new multifunctional optical biochip system that integrates an ellipsometer with a surface plasmon resonance (SPR) feature. This newly developed biochip biosensor, which we call ESPR for an ellipsometric SPR, provides us with a system to retrieve detailed information such as the optical properties of immobilized biomolecular monolayers, surface concentration variations of biomedical reactions, and kinetic affinity between biomolecules required for further biotech analysis. Our ESPR can also serve as both a research and development tool and a manufacturing tool for various biomedical applications.

  4. Dynamic coupling of plasmonic resonators

    PubMed Central

    Lee, Suyeon; Park, Q-Han

    2016-01-01

    We clarify the nature of dynamic coupling in plasmonic resonators and determine the dynamic coupling coefficient using a simple analytic model. We show that plasmonic resonators, such as subwavelength holes in a metal film which can be treated as bound charge oscillators, couple to each other through the retarded interaction of oscillating screened charges. Our dynamic coupling model offers, for the first time, a quantitative analytic description of the fundamental symmetric and anti-symmetric modes of coupled resonators which agrees with experimental results. Our model also reveals that plasmonic electromagnetically induced transparency arises in any coupled resonators of slightly unequal lengths, as confirmed by a rigorous numerical calculation and experiments. PMID:26911786

  5. Gold nanodisk array surface plasmon resonance sensor

    NASA Astrophysics Data System (ADS)

    Tian, Xueli

    Surface plasmon resonances in periodic metal nanostructures have been investigated for sensing applications over the last decade. The resonance wavelengths of the nanostructures are usually measured in the transmission or reflection spectrum for chemical and biological sensing. In this thesis, I introduce a nanoscale gap mediated surface plasmon resonance nanodisk array for displacement sensing and a super-period gold nanodisk grating enabled surface plasmon resonance spectrometer sensor. The super-period gold nanodisk grating has a small subwavelength period and a large diffraction grating period. Surface plasmon resonance spectra are measured in the first order diffraction spatial profiles captured by a charge-coupled device (CCD). A surface plasmon resonance sensor for the bovine serum albumin (BSA) protein nanolayer bonding is demonstrated by measuring the surface plasmon resonance shift in the first order diffraction spatial intensity profiles captured by the CCD.

  6. Fractional tunnelling resonance in plasmonic media

    PubMed Central

    Kang, Ji-Hun; -Han Park, Q.

    2013-01-01

    Metals can transmit light by tunnelling when they possess skin-depth thickness. Tunnelling can be resonantly enhanced if resonators are added to each side of a metal film, such as additional dielectric layers or periodic structures on a metal surface. Here we show that, even with no additional resonators, tunnelling resonance can arise if the metal film is confined and fractionally thin. In a slit waveguide filled with a negative permittivity metallic slab of thickness L, resonance is shown to arise at fractional thicknesses (L = Const./m; m = 1,2,3,…) by the excitation of ‘vortex plasmons'. We experimentally demonstrate fractional tunnelling resonance and vortex plasmons using microwave and negative permittivity metamaterials. The measured spectral peaks of the fractional tunnelling resonance and modes of the vortex plasmons agree with theoretical predictions. Fractional tunnelling resonance and vortex plasmons open new perspectives in resonance physics and promise potential applications in nanotechnology. PMID:23939460

  7. Nonlinear plasmonic amplification via dissipative soliton-plasmon resonances

    NASA Astrophysics Data System (ADS)

    Ferrando, Albert

    2017-01-01

    In this contribution we introduce a strategy for the compensation of plasmonic losses based on a recently proposed nonlinear mechanism: the resonant interaction between surface plasmon polaritons and spatial solitons propagating in parallel along a metal/dielectric/Kerr structure. This mechanism naturally leads to the generation of a quasiparticle excitation, the so-called soliplasmon resonance. We analyze the role played by the effective nonlinear coupling inherent to this system and how this can be used to provide a mechanism of quasiresonant nonlinear excitation of surface plasmon polaritons. We will pay particular attention to the introduction of asymmetric linear gain in the Kerr medium. The unique combination of nonlinear propagation, nonlinear coupling, and gain give rise to a scenario for the excitation of long-range surface plasmon polaritons with distinguishing characteristics. The connection between plasmonic losses and soliplasmon resonances in the presence of gain will be discussed.

  8. Plasmon resonant cavities in vertical nanowire arrays

    SciTech Connect

    Bora, M; Bond, T; Behymer, E; Chang, A

    2010-02-23

    We investigate tunable plasmon resonant cavity arrays in paired parallel nanowire waveguides. Resonances are observed when the waveguide length is an odd multiple of quarter plasmon wavelengths, consistent with boundary conditions of node and antinode at the ends. Two nanowire waveguides satisfy the dispersion relation of a planar metal-dielectric-metal waveguide of equivalent width equal to the square field average weighted gap. Confinement factors over 103 are possible due to plasmon focusing in the inter-wire space.

  9. Lasing Enhanced Surface Plasmon Resonance Sensing

    NASA Astrophysics Data System (ADS)

    Wang, Xing-Yuan; Wang, Yi-Lun; Wang, Suo; Li, Bo; Zhang, Xiao-Wei; Dai, Lun; Ma, Ren-Min

    2017-03-01

    The resonance phenomena of surface plasmons has enabled development of a novel class of noncontact, real-time and label-free optical sensors, which have emerged as a prominent tool in biochemical sensing and detection. However, various forms of surface plasmon resonances occur with natively strong non-radiative Drude damping that weakens the resonance and limits the sensing performance fundamentally. Here we experimentally demonstrate the first lasing-enhanced surface plasmon resonance (LESPR) refractive index sensor. The figure of merit (FOM) of intensity sensing is 84,000, which is about 400 times higher than state-of-the-art surface plasmon resonance (SPR) sensor. We found that the high FOM originates from three unique features of LESPR sensors: high-quality factor, nearly zero background emission and the Gaussian-shaped lasing spectra. The LESPR sensors may form the basis for a novel class of plasmonic sensors with unprecedented performance for a broad range of applications.

  10. Electrical Control of Optical Plasmon Resonance with Graphene

    DTIC Science & Technology

    2012-10-01

    at optical frequencies.10 Here we achieve efficient control of near- infrared plasmon resonance in a hybrid graphene-gold nanorod system. Exploiting...quality factor of gold nanorod plasmon. Our analysis shows that the plasmon− graphene coupling is remarkably strong: even a single electron in...events. KEYWORDS: Graphene, plasmon resonance, metamaterials, active plasmonics, gold nanorod , charge transfer sensor Surface plasmon resonance in

  11. Wedge Waveguides and Resonators for Quantum Plasmonics.

    PubMed

    Kress, Stephan J P; Antolinez, Felipe V; Richner, Patrizia; Jayanti, Sriharsha V; Kim, David K; Prins, Ferry; Riedinger, Andreas; Fischer, Maximilian P C; Meyer, Stefan; McPeak, Kevin M; Poulikakos, Dimos; Norris, David J

    2015-09-09

    Plasmonic structures can provide deep-subwavelength electromagnetic fields that are useful for enhancing light-matter interactions. However, because these localized modes are also dissipative, structures that offer the best compromise between field confinement and loss have been sought. Metallic wedge waveguides were initially identified as an ideal candidate but have been largely abandoned because to date their experimental performance has been limited. We combine state-of-the-art metallic wedges with integrated reflectors and precisely placed colloidal quantum dots (down to the single-emitter level) and demonstrate quantum-plasmonic waveguides and resonators with performance approaching theoretical limits. By exploiting a nearly 10-fold improvement in wedge-plasmon propagation (19 μm at a vacuum wavelength, λvac, of 630 nm), efficient reflectors (93%), and effective coupling (estimated to be >70%) to highly emissive (~90%) quantum dots, we obtain Ag plasmonic resonators at visible wavelengths with quality factors approaching 200 (3.3 nm line widths). As our structures offer modal volumes down to ~0.004λvac(3) in an exposed single-mode waveguide-resonator geometry, they provide advantages over both traditional photonic microcavities and localized-plasmonic resonators for enhancing light-matter interactions. Our results confirm the promise of wedges for creating plasmonic devices and for studying coherent quantum-plasmonic effects such as long-distance plasmon-mediated entanglement and strong plasmon-matter coupling.

  12. Optical biosensors using surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Homola, Jiri; Brynda, Eduard; Tobiska, Petr; Tichy, Ivo; Skvor, Jiri

    1999-12-01

    We present a surface plasmon resonance sensor base on prism excitation of surface plasmons and spectral interrogation. For specific detection of biomolecular analytes, multilayers of monoclonal antibodies are immobilized on the surface of the sensor. Detection of biomolecular analytes such as human (beta) -2)-microglobulin, choriogonadotropin, hepatitis B surface antigen, salmonella enteritidis is demonstrated.

  13. Microcavity surface plasmon resonance bio-sensors

    NASA Astrophysics Data System (ADS)

    Mosavian, Nazanin

    This work discusses a miniature surface plasmon biosensor which uses a dielectric sub- micron diameter core with gold spherical shell. The shell has a subwavelength nanoaperture believed to excite stationary plasmon resonances at the biosensor's surface. The sub-micron cavity enhances the measurement sensitivity of molecules binding to the sensor surface. We used visible-range optical spectroscopy to study the wavelength shift as bio-molecules absorbed-desorbed at the shell surface. We also used Scanning Electron Microscopy (SEM) and Focused Ion Beam (FIB) ablation to study the characteristics of microcavity surface plasmon resonance sensor (MSPRS) and the inner structure formed with metal deposition and its spectrum. We found that resonances at 580 nm and 670 nm responded to bound test agents and that Surface Plasmon Resonance (SPR) sensor intensity could be used to differentiate between D-glucose and L-glucose. The responsiveness of the system depended upon the mechanical integrity of the metallic surface coating.

  14. Plasmon resonant cavities in vertical nanowire arrays

    DOEpatents

    Bora, Mihail; Bond, Tiziana C.; Fasenfest, Benjamin J.; Behymer, Elaine M.

    2014-07-15

    Tunable plasmon resonant cavity arrays in paired parallel nanowire waveguides are presented. Resonances can be observed when the waveguide length is an odd multiple of quarter plasmon wavelengths, consistent with boundary conditions of node and antinode at the ends. Two nanowire waveguides can satisfy the dispersion relation of a planar metal-dielectric-metal waveguide of equivalent width equal to the square field average weighted gap. Confinement factors of over 10.sup.3 are possible due to plasmon focusing in the inter-wire space.

  15. Plasmonic black metals in resonant nanocavities

    NASA Astrophysics Data System (ADS)

    Bora, Mihail; Behymer, Elaine M.; Dehlinger, Dietrich A.; Britten, Jerald A.; Larson, Cindy C.; Chang, Allan S. P.; Munechika, Keiko; Nguyen, Hoang T.; Bond, Tiziana C.

    2013-06-01

    We investigate a plasmonic resonant structure tunable from ultra-violet to near infrared wavelengths with maximum absorbance strength over 95% due to a highly efficient coupling with incident light. Additional harmonics are excited at higher frequencies extending the absorbance range to multiple wavelengths. We propose the concept of a plasmonic black metal nanoresonator that exhibits broadband absorbance characteristics by spacing the modes closer through increasing the resonator length and by employing adiabatic plasmonic nano-focusing on the tapered end of the cavity.

  16. Surface plasmon resonance for proteomics.

    PubMed

    de Mol, Nico J

    2012-01-01

    Surface plasmon resonance (SPR) is a well-established label-free technique to detect mass changes near an SPR surface. For 20 years the benefits of SPR have been proven in biomolecular interaction analysis, including measurements of affinity and kinetics. The emergence of proteomics and a need for high throughput analysis drives the development of SPR systems capable of analyzing microarrays. The use of SPR imaging (also known as SPR microscopy) makes it possible to use multiplexed arrays to follow binding reactions. As SPR only analyzes the binding process, but not the identity of captured molecules on the SPR surface, technologies have been developed to integrate SPR with mass spectrometric (MS) analysis. Such approaches involve the recovery of analytes from the SPR surface and subsequent MALDI-TOF MS analysis, or LC-MS/MS after tryptic digestion of recovered proteins. An approach compatible with SPR arrays is on-chip MALDI-TOF MS, from arrayed spots on an SPR surface. This review describes some exciting developments in the application of SPR to proteomics, using instruments which are on the market already, or are expected to be available in the years to come.

  17. Critical coupling in plasmonic resonator arrays

    NASA Astrophysics Data System (ADS)

    Balci, Sinan; Kocabas, Coskun; Aydinli, Atilla

    2011-08-01

    We report critical coupling of electromagnetic waves to plasmonic cavity arrays fabricated on Moiré surfaces. Dark field plasmon microscopy imaging and polarization dependent spectroscopic reflection measurements reveal the critical coupling conditions of the cavities. The critical coupling conditions depend on the superperiod of the Moiré surface, which also defines the coupling between the cavities. Complete transfer of the incident power can be achieved for traveling wave plasmonic resonators, which have a relatively short superperiod. When the superperiod of the resonators increases, the coupled resonators become isolated standing wave resonators in which complete transfer of the incident power is not possible. Analytical and finite difference time domain calculations support the experimental observations.

  18. Triple plasmon resonance of bimetal nanoshell

    SciTech Connect

    Shirzaditabar, Farzad; Saliminasab, Maryam; Arghavani Nia, Borhan

    2014-07-15

    In this paper, light absorption spectra properties of a bimetal multilayer nanoshell based on quasi-static approach are investigated. Comparing with silver-dielectric-silver and silver-dielectric-gold nanoshells, gold-dielectric-silver nanoshells have three intense and separated plasmon peaks which are more suitable for multiplex biosensing. Calculations show that relatively small thickness of outer silver shell and large dielectric constant of middle dielectric layer of gold-dielectric-silver nanoshell are suitable to obtain the triple plasmon resonance.

  19. Triple plasmon resonance of bimetal nanoshell

    NASA Astrophysics Data System (ADS)

    Shirzaditabar, Farzad; Saliminasab, Maryam; Arghavani Nia, Borhan

    2014-07-01

    In this paper, light absorption spectra properties of a bimetal multilayer nanoshell based on quasi-static approach are investigated. Comparing with silver-dielectric-silver and silver-dielectric-gold nanoshells, gold-dielectric-silver nanoshells have three intense and separated plasmon peaks which are more suitable for multiplex biosensing. Calculations show that relatively small thickness of outer silver shell and large dielectric constant of middle dielectric layer of gold-dielectric-silver nanoshell are suitable to obtain the triple plasmon resonance.

  20. Spectroscopic studies of individual plasmon resonant nanoparticles

    NASA Astrophysics Data System (ADS)

    Mock, Jack J.; Smith, David R.; Barbic, Mladen; Oldenburg, Steven J.; Schultz, David A.; Schultz, Sheldon

    2003-11-01

    We present a detailed description of the apparatus and techniques that we have utilized in our experimental study of individual plas on resonant nanoparticles,along with a brief description of some major results. The apparatus consists of a spectroscopic system combined with a modified darkfield microscope, which enables the user to sequentially select individual resonant nanostructures in the microscopic field of view for spectroscopic study. Plasmon resonant nanostructures scatter light elastically,and typically have very large scattering cross-sections at their resonant optical wavelengths. In general, spectra can be obtained with acquisition times between .1 to 30 seconds,and color images can be captured using consumer digital color cameras. Spheres,tetrahedrons,and pentagonal platelets were fabricated using colloidal chemistry techniques. To produce highly anisotropic structures such as nanorods and "barbells", templates were used. Many of these nanostructures have been individually spectroscopically characterized,and their spectra correlated with their shape and size as determined by transmission electron icroscope (TEM). The unique shape,size, composition,and dielectric surroundings of the individual plasmon resonant nanostructures determine their plasmon resonant behavior. We will show how the composition of the substrate on which the particles are immobilized and the dielectric of the surrounding medium have a significant effect on the plasmon resonance of the individual particles.

  1. Dark Field Imaging of Plasmonic Resonator Arrays

    NASA Astrophysics Data System (ADS)

    Aydinli, Atilla; Balci, Sinan; Karademir, Ertugrul; Kocabas, Coskun

    2012-02-01

    We present critical coupling of electromagnetic waves to plasmonic cavity arrays fabricated on Moir'e surfaces. The critical coupling condition depends on the superperiod of Moir'e surface, which also defines the coupling between the cavities. Complete transfer of the incident power can be achieved for traveling wave plasmonic resonators, which have relatively short superperiod. When the superperiod of the resonators increases, the coupled resonators become isolated standing wave resonators in which complete transfer of the incident power is not possible. Dark field plasmon microscopy imaging and polarization dependent spectroscopic reflection measurements reveal the critical coupling conditions of the cavities. We image the light scattered from SPPs in the plasmonic cavities excited by a tunable light source. Tuning the excitation wavelength, we measure the localization and dispersion of the plasmonic cavity mode. Dark field imaging has been achieved in the Kretschmann configuration using a supercontinuum white light laser equipped with an acoustooptic tunable filter. Polarization dependent spectroscopic reflection and dark field imaging measurements are correlated and found to be in agreement with FDTD simulations.

  2. Gap Plasmon Resonance in a Suspended Plasmonic Nanowire Coupled to a Metallic Substrate.

    PubMed

    Miyata, Masashi; Holsteen, Aaron; Nagasaki, Yusuke; Brongersma, Mark L; Takahara, Junichi

    2015-08-12

    We present an experimental demonstration of nanoscale gap plasmon resonators that consist of an individual suspended plasmonic nanowire (NW) over a metallic substrate. Our study demonstrates that the NW supports strong gap plasmon resonances of various gap sizes including single-nanometer-scale gaps. The obtained resonance features agree well with intuitive resonance models for near- and far-field regimes. We also illustrate that our suspended NW geometry is capable of constructing plasmonic coupled systems dominated by quasi-electrostatics.

  3. Geometric interpretations for resonances of plasmonic nanoparticles

    PubMed Central

    Liu, Wei; Oulton, Rupert F.; Kivshar, Yuri S.

    2015-01-01

    The field of plasmonics can be roughly categorized into two branches: surface plasmon polaritons (SPPs) propagating in waveguides and localized surface plasmons (LSPs) supported by scattering particles. Investigations along these two directions usually employ different approaches, resulting in more or less a dogma that the two branches progress almost independently of each other, with few interactions. Here in this work we interpret LSPs from a Bohr model based geometric perspective relying on SPPs, thus establishing a connection between these two sub-fields. Besides the clear explanations of conventional scattering features of plasmonic nanoparticles, based on this geometric model we further demonstrate other anomalous scattering features (higher order modes supported at lower frequencies, and blueshift of the resonance with increasing particle sizes) and multiple electric resonances of the same order supported at different frequencies, which have been revealed to originate from backward SPP modes and multiple dispersion bands supported in the corresponding plasmonic waveguides, respectively. Inspired by this geometric model, it is also shown that, through solely geometric tuning, the absorption of each LSP resonance can be maximized to reach the single channel absorption limit, provided that the scattering and absorption rates are tuned to be equal. PMID:26173797

  4. Integrated plasmonic refractometric sensor using Fano resonance

    NASA Astrophysics Data System (ADS)

    Sherif, S. M.; Zografopoulos, D. C.; Shahada, L. A.; Beccherelli, R.; Swillam, M.

    2017-02-01

    We propose a plasmonic refractometric sensor that is based on Fano resonances excited in a resonant rectangular cavity coupled to a metal-insulator-metal bus waveguide. The properties of the resonances are controlled by varying the dimensions of the rectangular resonator and the observed Fano profile stems from the multimode interference of resonant cavity modes. We theoretically investigate the device’s performance as a highly sensitive refractometric plasmonic sensor which operates on gases, water and organic solvent solutions with tens of femtoliters of analyte. The sensor is studied in a wide operational range (0.7-2.7 μm) covering the entire near infrared spectral range, and is characterized by large sensitivity, which reaches 1550 nm RIU-1, and sensitivity per unit volume higher than 107 nm (RIU · nl)-1 at the resonant wavelength of 1.55 μm. The proposed plasmonic structure is very promising for integrated sensing applications owing to its small footprint and surprisingly simple layout.

  5. Hybrid plasmonic-photonic resonators (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Koenderink, A. Femius; Doeleman, Hugo M.; Ruesink, Freek; Verhagen, Ewold; Osorio, Clara I.

    2016-09-01

    Hybrid nanophotonic structures are structures that integrate different nanoscale platforms to harness light-matter interaction. We propose that combinations of plasmonic antennas inside modest-Q dielectric cavities can lead to very high Purcell factors, yielding plasmonic mode volumes at essentially cavity quality factors. The underlying physics is subtle: for instance, how plasmon antennas with large cross sections spoil or improve cavities and vice versa, contains physics beyond perturbation theory, depending on interplays of back-action, and interferences. This is evident from the fact that the local density of states of hybrid systems shows the rich physics of Fano interferences. I will discuss recent scattering experiments performed on toroidal microcavities coupled to plasmon particle arrays that probe both cavity resonance shifts and particle polarizability changes illustrating these insights. Furthermore I will present our efforts to probe single plasmon antennas coupled to emitters and complex environments using scatterometry. An integral part of this approach is the recently developed measurement method of `k-space polarimetry', a microscopy technique to completely classify the intensity and polarization state of light radiated by a single nano-object into any emission direction that is based on back focal plane imaging and Stokes polarimetry. I show benchmarks of this technique for the cases of scattering, fluorescence, and cathodoluminescence applied to directional surface plasmon polariton antennas.

  6. Nonlinear plasmonic resonances in graphene nanostructures

    NASA Astrophysics Data System (ADS)

    You, Jian Wei; Weismann, Martin; Panoiu, Nicolae C.

    2016-09-01

    Peculiar physical properties of graphene offer remarkable potential for advanced photonics, particularly in the area of nonlinear optics at deep-subwavelength scale. In this article, we use a theoretical and computational analysis to demonstrate an efficient mechanism for enhancing the third-harmonic generation in graphene diffraction gratings. By taking advantage of the relation between the resonance wavelength of localized surface-plasmon polaritons of graphene ribbons and disks their specific geometry, we can engineer the spectral response of graphene gratings so as strong plasmonic resonances exist at both the fundamental frequency and third-harmonic (TH). As a result of this dual resonance mechanism for optical near-field enhancement, the intensity of the TH can be increased greatly.

  7. Resonant plasmon nanofocusing by closed tapered gaps.

    PubMed

    Søndergaard, Thomas; Bozhevolnyi, Sergey I; Beermann, Jonas; Novikov, Sergey M; Devaux, Eloïse; Ebbesen, Thomas W

    2010-01-01

    We study radiation nanofocusing by closed tapered gaps, i.e. metal V-grooves, under normal illumination, and discover that the local field inside a groove can be resonantly enhanced due to interference of counter-propagating gap plasmons. Considering V-grooves milled in gold, we analyze this phenomenon theoretically, deriving an analytic expression for the resonance condition and predicting more than 550-fold intensity enhancements at resonance, and observe it experimentally with two-photon photoluminescence microscopy, demonstrating more than 100-fold intensity enhancements.

  8. Miniature fiber optic surface plasmon resonance biosensors

    NASA Astrophysics Data System (ADS)

    Slavik, Radan; Brynda, Eduard; Homola, Jiri; Ctyroky, Jiri

    1999-01-01

    A novel design of surface plasmon resonance fiber optic sensor is reported which leads to a compact, highly miniaturized sensing element with excellent sensitivity. The sensing device is based on a side-polished single-mode optical fiber with a thin metal overlayer supporting surface plasmon waves. The strength of interaction between a fiber mode and a surface plasmon wave depends strongly on the refractive index near the sensing surface. Therefore, refractive index changes associated with biospecific interaction between antibodies immobilized on the sensor and antigen molecules can be monitored by measuring light intensity variations. Detection of horse radish peroxidase (HRP) of the concentration of 100 ng/ml has been accomplished using the fiber optic sensor with a matrix of monoclonal antibodies against HRP immobilized on the sensor surface.

  9. Gap-plasmon nanoantennas and bowtie resonators

    NASA Astrophysics Data System (ADS)

    Gramotnev, Dmitri K.; Pors, Anders; Willatzen, Morten; Bozhevolnyi, Sergey I.

    2012-01-01

    Plasmonic bowtie resonators involving gap surface plasmons (GSPs) in metal-insulator-metal (MIM) structures, in which only the top metal layer is structured, are investigated using numerical simulations. We demonstrate that the considered configuration features two efficiently excitable GSP resonances associated with distinct charge distributions with the domination of the dipole and quadrupole moments resulting in low- and high-Q resonances, respectively. The typical Q factors for the high-Q resonances are shown to achieve ˜25 in the near-infrared, thus potentially exceeding the quasistatic limit. Detailed physical interpretations of the obtained results and consistent dependencies of the resonance characteristics on the geometrical structural parameters are presented. Excellent resonant characteristics, the simplicity of fabrication, and tuning of the resonance wavelength by adjusting the size of the bowtie arms, separation between them, and/or thickness of the insulator (SiO2) layer in the MIM structure appear attractive for a wide variety of applications, ranging from surface sensing to photovoltaics.

  10. Laser printing of resonant plasmonic nanovoids

    NASA Astrophysics Data System (ADS)

    Kuchmizhak, A.; Vitrik, O.; Kulchin, Yu.; Storozhenko, D.; Mayor, A.; Mirochnik, A.; Makarov, S.; Milichko, V.; Kudryashov, S.; Zhakhovsky, V.; Inogamov, N.

    2016-06-01

    Hollow reduced-symmetry resonant plasmonic nanostructures possess pronounced tunable optical resonances in the UV-vis-IR range, being a promising platform for advanced nanophotonic devices. However, the present fabrication approaches require several consecutive technological steps to produce such nanostructures, making their large-scale fabrication rather time-consuming and expensive. Here, we report on direct single-step fabrication of large-scale arrays of hollow parabolic- and cone-shaped nanovoids in silver and gold thin films, using single-pulse femtosecond nanoablation at high repetition rates. The lateral and vertical size of such nanovoids was found to be laser energy-tunable. Resonant light scattering from individual nanovoids was observed in the visible spectral range, using dark-field confocal microspectroscopy, with the size-dependent resonant peak positions. These colored geometric resonances in far-field scattering were related to excitation and interference of transverse surface plasmon modes in nanovoid shells. Plasmon-mediated electromagnetic field enhancement near the nanovoids was evaluated via finite-difference time-domain calculations for their model shapes simulated by three-dimensional molecular dynamics, and experimentally verified by means of photoluminescence microscopy and Raman spectroscopy.Hollow reduced-symmetry resonant plasmonic nanostructures possess pronounced tunable optical resonances in the UV-vis-IR range, being a promising platform for advanced nanophotonic devices. However, the present fabrication approaches require several consecutive technological steps to produce such nanostructures, making their large-scale fabrication rather time-consuming and expensive. Here, we report on direct single-step fabrication of large-scale arrays of hollow parabolic- and cone-shaped nanovoids in silver and gold thin films, using single-pulse femtosecond nanoablation at high repetition rates. The lateral and vertical size of such nanovoids was

  11. Plasmon resonant liposomes for controlled drug delivery

    NASA Astrophysics Data System (ADS)

    Knights-Mitchell, Shellie S.; Romanowski, Marek

    2015-03-01

    Nanotechnology use in drug delivery promotes a reduction in systemic toxicity, improved pharmacokinetics, and better drug bioavailability. Liposomes continue to be extensively researched as drug delivery systems (DDS) with formulations such as Doxil® and Ambisome® approved by FDA and successfully marketed in the United States. However, the limited ability to precisely control release of active ingredients from these vesicles continues to challenge the broad implementation of this technology. Moreover, the full potential of the carrier to sequester drugs until it can reach its intended target has yet to be realized. Here, we describe a liposomal DDS that releases therapeutic doses of an anticancer drug in response to external stimulus. Earlier, we introduced degradable plasmon resonant liposomes. These constructs, obtained by reducing gold on the liposome surface, facilitate spatial and temporal release of drugs upon laser light illumination that ultimately induces an increase in temperature. In this work, plasmon resonant liposomes have been developed to stably encapsulate and retain doxorubicin at physiological conditions represented by isotonic saline at 37o C and pH 7.4. Subsequently, they are stimulated to release contents either by a 5o C increase in temperature or by laser illumination (760 nm and 88 mW/cm2 power density). Successful development of degradable plasmon resonant liposomes responsive to near-infrared light or moderate hyperthermia can provide a new delivery method for multiple lipophilic and hydrophilic drugs with pharmacokinetic profiles that limit clinical utility.

  12. Large-area nanogap plasmon resonator arrays for plasmonics applications

    NASA Astrophysics Data System (ADS)

    Jin, Mingliang; van Wolferen, Henk; Wormeester, Herbert; van den Berg, Albert; Carlen, Edwin T.

    2012-07-01

    Large-area (~8000 mm2) Au nanogap plasmon resonator array substrates manufactured using maskless laser interference lithography (LIL) with high uniformity are presented. The periodically spaced subwavelength nanogap arrays are formed between adjacent nanopyramid (NPy) structures with precisely defined pitch and high length density (~1 km cm-2), and are ideally suited as scattering sites for surface enhanced Raman scattering (SERS), as well as refractive index sensing. The two-dimensional grid arrangement of NPy structures renders the excitation of the plasmon resonators minimally dependent on the incident polarization. The SERS average enhancement factor (AEF) has been characterized using over 30 000 individual measurements of benzenethiol (BT) chemisorbed on the Au NPy surfaces. From the 1(a1), βCCC + νCS ring mode (1074 cm-1) of BT on surfaces with pitch λg = 200 nm, AEF = 0.8 × 106 and for surfaces with λg = 500 nm, AEF = 0.3 × 107 from over 99% of the imaged spots. Maximum AEFs > 108 have been measured in both cases.

  13. Plasmon Resonators for Quantum Computing

    DTIC Science & Technology

    2007-06-01

    quantum dot. For free atoms this strong coupling is achieved using high Q optical resonators, such as ultra-low-loss bulk Fabry - Perot cavities or...TR-07-0487 11. SUPPLEMENTARY NOTES 12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Unlimited UL 13. ABSTRACT (Maximum 200 words) The

  14. Plasmonic Gold Decorated MWCNT Nanocomposite for Localized Plasmon Resonance Sensing

    PubMed Central

    Ozhikandathil, J.; Badilescu, S.; Packirisamy, M.

    2015-01-01

    The synergism of excellent properties of carbon nanotubes and gold nanoparticles is used in this work for bio-sensing of recombinant bovine growth hormones (rbST) by making Multi Wall Carbon Nanotubes (MWCNT) locally optically responsive by augmenting it optical properties through Localized Surface Plasmon Resonance (LSPR). To this purpose, locally gold nano particles decorated gold–MWCNT composite was synthesized from a suspension of MWCNT bundles and hydrogen chloroauric acid in an aqueous solution, activated ultrasonically and, then, drop-casted on a glass substrate. The slow drying of the drop produces a “coffee ring” pattern that is found to contain gold–MWCNT nanocomposites, accumulated mostly along the perimeter of the ring. The reaction is studied also at low-temperature, in the vacuum chamber of the Scanning Electron Microscope and is accounted for by the local melting processes that facilitate the contact between the bundle of tubes and the gold ions. Biosensing applications of the gold–MWCNT nanocomposite using their LSPR properties are demonstrated for the plasmonic detection of traces of bovine growth hormone. The sensitivity of the hybrid platform which is found to be 1 ng/ml is much better than that measuring with gold nanoparticles alone which is only 25 ng/ml. PMID:26282187

  15. Plasmonic Gold Decorated MWCNT Nanocomposite for Localized Plasmon Resonance Sensing

    NASA Astrophysics Data System (ADS)

    Ozhikandathil, J.; Badilescu, S.; Packirisamy, M.

    2015-08-01

    The synergism of excellent properties of carbon nanotubes and gold nanoparticles is used in this work for bio-sensing of recombinant bovine growth hormones (rbST) by making Multi Wall Carbon Nanotubes (MWCNT) locally optically responsive by augmenting it optical properties through Localized Surface Plasmon Resonance (LSPR). To this purpose, locally gold nano particles decorated gold-MWCNT composite was synthesized from a suspension of MWCNT bundles and hydrogen chloroauric acid in an aqueous solution, activated ultrasonically and, then, drop-casted on a glass substrate. The slow drying of the drop produces a “coffee ring” pattern that is found to contain gold-MWCNT nanocomposites, accumulated mostly along the perimeter of the ring. The reaction is studied also at low-temperature, in the vacuum chamber of the Scanning Electron Microscope and is accounted for by the local melting processes that facilitate the contact between the bundle of tubes and the gold ions. Biosensing applications of the gold-MWCNT nanocomposite using their LSPR properties are demonstrated for the plasmonic detection of traces of bovine growth hormone. The sensitivity of the hybrid platform which is found to be 1 ng/ml is much better than that measuring with gold nanoparticles alone which is only 25 ng/ml.

  16. Liquid crystal filled surface plasmon resonance thermometer.

    PubMed

    Lu, Mengdi; Zhang, Xinpu; Liang, Yuzhang; Li, Lixia; Masson, Jean-Francois; Peng, Wei

    2016-05-16

    A novel surface plasmon resonance (SPR) thermometer based on liquid crystal (LC) filled hollow fiber is demonstrated in this paper. A hollow fiber was internally coated with silver and then filled with LC. The SPR response to temperature was studied using modeling and verified experimentally. The results demonstrated that the refractive index of LC decreases with the increasing temperature and the variation can be detected by the resonance wavelength shift of the plasmon resonance. The temperature sensitivities were 4.72 nm/°C in the temperature range of 20 to 34.5 °C and 0.55 nm/°C in the temperature range of 36 to 50 °C, At the phase transition temperature between nematic and isotropic phases of the LC, the temperature sensitivity increased by one order of magnitude and a shift of more than 46 nm was observed with only a 1.5 °C temperature change. This sensor can be used for temperature monitoring and alarming, and can be extended for other physical parameter measurement.

  17. Fano Resonances in Plasmonic Nanoclusters: Geometrical and Chemical Tunability

    SciTech Connect

    Lassiter, J. Britt; Sobhani, Heidar; Fan, Jonathan A.; Kundu, Janardan; Capasso, Federico; Nordlander, Peter; Halas, Naomi J.

    2010-08-11

    Clusters of plasmonic nanoparticles and nanostructures support Fano resonances. Here we show that this spectral feature, produced by the interference between bright and dark modes of the nanoparticle cluster, is strongly dependent upon both geometry and local dielectric environment. This permits a highly sensitive tunability of the Fano dip in both wavelength and amplitude by varying cluster dimensions, geometry, and relative size of the individual nanocluster components. Plasmonic nanoclusters show an unprecedented sensitivity to dielectric environment with a local surface plasmon resonance figure of merit of 5.7, the highest yet reported for localized surface plasmon resonance sensing in a finite nanostructure.

  18. Plasmonic resonances of silver nano-particles

    NASA Astrophysics Data System (ADS)

    Sukharenko, Vitaly; Suslov, Anatoliy; Dorsinville, Roger

    2016-09-01

    Silver (Ag) nanoparticles (NPs) have unique optical, electrical, and thermal properties that are being incorporated into products ranging from optical communication devices and photovoltaics to biological, DNA and other chemical sensors. The optical properties of silver nanoparticles are strongly influenced by their shape, size, distribution, and surrounding environment. One of the main challenges is to maximize the coupling efficiency of incident radiation into plasmonic resonances. In this paper, we present a method to optimize the selection of mono-dispersed Ag NPs size and the wavelength of incident radiation to enhance coupling efficiency. The results are supported by experimental measurements of optical properties of mono-dispersed silver nanoparticles.

  19. Artificial DNA and surface plasmon resonance

    PubMed Central

    D'Agata, Roberta; Spoto, Giuseppe

    2012-01-01

    The combined use of surface plasmon resonance (SPR) and modified or mimic oligonucleotides have expanded diagnostic capabilities of SPR-based biosensors and have allowed detailed studies of molecular recognition processes. This review summarizes the most significant advances made in this area over the past 15 years.   Functional and conformationally restricted DNA analogs (e.g., aptamers and PNAs) when used as components of SPR biosensors contribute to enhance the biosensor sensitivity and selectivity. At the same time, the SPR technology brings advantages that allows forbetter exploration of underlying properties of non-natural nucleic acid structures such us DNAzymes, LNA and HNA. PMID:22821257

  20. Proximity Resonance and Localized Surface Plasmons

    NASA Astrophysics Data System (ADS)

    Liu, Bo; Heller, Eric

    2014-03-01

    The collective excitation of conduction electrons in subwavelength nanostructures is known as Localized Surface Plasmon(LSP)[1]. Such plasmon modes has been intensively studied using noble nanoparticles . More recently, the possibility of building terahertz metamaterials supporting such LSP modes has been explored in graphene microribbons and microdisks. Unlike Surface Plasmon Polaritons(SPPs) at metal-insulator interface, LSP can be directly excited by light illumination and holds promise for applications in ultrasensitive biosensing, nano-optical tweezers and improved photovoltaic devices. In this paper, we consider the interaction of two LSPs in the weak coupling regime and show how an effect similar to the proximity resonance in the quantum scattering theory) gives rise to an asymmetric(quadrupole) mode with increased damping rate. The existence of this asymmetric mode relies on a small phase retardation between the two LSPs. This phase retardation, though small, is key to both increased damping rate for the asymmetric mode and reduced damping rate for the symmetric mode. When this small phase retardation is removed by changing the polarization of the exciting light,we show that the asymmetric mode can not be excited and the symmetric mode shows increased damping.

  1. Interacting Dark Resonances with Plasmonic Meta-Molecules

    DTIC Science & Technology

    2014-09-17

    Interacting dark resonances with plasmonic meta-molecules Pankaj K. Jha,1 Michael Mrejen,1 Jeongmin Kim,1 Chihhui Wu,1 Xiaobo Yin,1 Yuan Wang,1 and...optics, and information theory. Here, we investigate interacting dark resonance type physics in multi-layered plasmonic meta-molecules. We...theoretically demonstrate that these plasmonic meta-molecules exhibit sub-natural spectral response, analogous to conventional atomic four-level configuration, by

  2. Excitation of plasmonic nanoantennas by nonresonant and resonant electron tunnelling

    NASA Astrophysics Data System (ADS)

    Uskov, Alexander V.; Khurgin, Jacob B.; Protsenko, Igor E.; Smetanin, Igor V.; Bouhelier, Alexandre

    2016-07-01

    A rigorous theory of photon emission generated by inelastic electron tunnelling inside the gap of plasmonic nanoantennas is developed. The disappointingly low efficiency of the electrical excitation of surface plasmon polaritons in these structures can be increased by orders of magnitude when a resonant tunnelling structure is incorporated inside the gap. A resonant tunnelling assisted surface plasmon emitter may become a key element in future electrically-driven plasmonic nanocircuits.A rigorous theory of photon emission generated by inelastic electron tunnelling inside the gap of plasmonic nanoantennas is developed. The disappointingly low efficiency of the electrical excitation of surface plasmon polaritons in these structures can be increased by orders of magnitude when a resonant tunnelling structure is incorporated inside the gap. A resonant tunnelling assisted surface plasmon emitter may become a key element in future electrically-driven plasmonic nanocircuits. Electronic supplementary information (ESI) available: Plasmonic mode in nanowires, the probability of stimulated emission in tunnelling through the Fermi's Golden Rule and electron wave functions in tunnelling structures with nonresonant and resonant tunnelling. See DOI: 10.1039/c6nr01931e

  3. Terahertz plasmons in coupled two-dimensional semiconductor resonators

    NASA Astrophysics Data System (ADS)

    Sydoruk, O.; Wu, J. B.; Mayorov, A.; Wood, C. D.; Mistry, D. K.; Cunningham, J. E.

    2015-11-01

    Advances in theory are needed to match recent progress in measurements of coupled semiconductor resonators supporting terahertz plasmons. Here, we present a field-based model of plasmonic resonators that comprise gated and ungated two-dimensional electron systems. The model is compared to experimental measurements of a representative system, in which the interaction between the gated and ungated modes leads to a rich spectrum of hybridized resonances. A theoretical framework is thus established for the analysis and design of gated low-dimensional systems used as plasmonic resonators, underlining their potential application in the manipulation of terahertz frequency range signals.

  4. Plasmon Resonance Methods in GPCR Signaling and Other Membrane Events

    PubMed Central

    Alves, I.D.; Park, C.K.; Hruby, V.J.

    2005-01-01

    The existence of surface guided electromagnetic waves has been theoretically predicted from Maxwell’s equations and investigated during the first decades of the 20th century. However, it is only since the late 1960’s that they have attracted the interest of surface physicists and earned the moniker of “surface plasmon”. With the advent of commercially available instruments and well established theories, the technique has been used to study a wide variety of biochemical and biotechnological phenomena. Spectral response of the resonance condition serves as a sensitive indicator of the optical properties of thin films immobilized within a wavelength of the surface. This enhanced surface sensitivity has provided a boon to the surface sciences, and fosters collaboration between surface chemistry, physics and the ongoing biological and biotechnological revolution. Since then, techniques based on surface plasmons such as Surface Plasmon Resonance (SPR), SPR Imaging, Plasmon Waveguide Resonance (PWR) and others, have been increasingly used to determine the affinity and kinetics of a wide variety of real time molecular interactions such as protein-protein, lipid-protein and ligand-protein, without the need for a molecular tag or label. The physical-chemical methodologies used to immobilize membranes at the surface of these optical devices are reviewed, pointing out advantages and limitations of each method. The paper serves to summarize both historical and more recent developments of these technologies for investigating structure-function aspects of these molecular interactions, and regulation of specific events in signal transduction by G-protein coupled receptors (GPCRs). PMID:16101432

  5. Plasmonic EIT-like switching in bright-dark-bright plasmon resonators.

    PubMed

    Chen, Junxue; Wang, Pei; Chen, Chuncong; Lu, Yonghua; Ming, Hai; Zhan, Qiwen

    2011-03-28

    In this paper we report the study of the electromagnetically induced transparency (EIT)-like transmission in the bright-dark-bright plasmon resonators. It is demonstrated that the interferences between the dark plasmons excited by two bright plasmon resonators can be controlled by the incident light polarization. The constructive interference strengthens the coupling between the bright and dark resonators, leading to a more prominent EIT-like transparency window of the metamaterial. In contrary, destructive interference suppresses the coupling between the bright and dark resonators, destroying the interference pathway that forms the EIT-like transmission. Based on this observation, the plasmonic EIT switching can be realized by changing the polarization of incident light. This phenomenon may find applications in optical switching and plasmon-based information processing.

  6. Plasmon resonance energy transfer and plexcitonic solar cell.

    PubMed

    Nan, Fan; Ding, Si-Jing; Ma, Liang; Cheng, Zi-Qiang; Zhong, Yu-Ting; Zhang, Ya-Fang; Qiu, Yun-Hang; Li, Xiaoguang; Zhou, Li; Wang, Qu-Quan

    2016-08-11

    Plasmon-mediated energy transfer is highly desirable in photo-electronic nanodevices, but the direct injection efficiency of "hot electrons" in plasmonic photo-detectors and plasmon-sensitized solar cells (plasmon-SSCs) is poor. On another front, Fano resonance induced by strong plasmon-exciton coupling provides an efficient channel of coherent energy transfer from metallic plasmons to molecular excitons, and organic dye molecules have a much better injection efficiency in exciton-SSCs than "hot electrons". Here, we investigate enhanced light-harvesting of chlorophyll-a molecules strongly coupled to Au nanostructured films via Fano resonance. The enhanced local field and plasmon resonance energy transfer are experimentally revealed by monitoring the ultrafast dynamical processes of the plexcitons and the photocurrent flows of the assembled plexciton-SSCs. By tuning the Fano factor and anti-resonance wavelengths, we find that the local field is largely enhanced and the efficiency of plexciton-SSCs consisting of ultrathin TiO2 films is significantly improved. Most strikingly, the output power of the plexciton-SSCs is much larger than the sum of those of the individual plasmon- and exciton-SSCs. Our observations provide a practical approach to monitor energy and electron transfer in plasmon-exciton hybrids at a strong coupling regime and also offer a new strategy to design photovoltaic nanodevices.

  7. Pesticides sensing by surface plasmon resonance

    SciTech Connect

    Kalabina, N.A.; Ksenevich, T.I.; Beloglazov, A.A.; Nikitin, P.I.

    1995-12-31

    High toxicity of pesticides and their wide use in agriculture, represent a general danger for environmental welfare and could become a real threat to life. Screening of pesticides in the environment has become very important during last years due to low threshold values for pesticides in drinking water. An optical biosensor has been developed for detection of pesticides, based on surface plasmon resonance (SPR) technique. Concentration of the pesticides was measured in liquid or gas. The authors specially originated organic film on a disposable element. A setup on the base of the Kretschmann arrangement was improved by using a computer-controlled angular scanning system. The detection concentration limit of dinitrophenole (DNP) was 10{sup {minus}9} M. Some samples exhibited effect down to 10{sup {minus}11} M of DNP. The results obtained provide reason for further development of SPR sensor as applied to pesticides monitoring.

  8. Understanding Plasmon Resonances using Theoretical Methods

    NASA Astrophysics Data System (ADS)

    Aikens, Christine

    2015-03-01

    Theoretical investigations of noble metal nanoparticles play an important role in determining the origins of the unique chemical and physical properties of these systems that lead to applications in photonics, sensing, catalysis, etc. Time-dependent density functional theory (TDDFT) has been employed to calculate the absorption spectrum for pentagonal silver nanorods. The wavelength of their absorption maxima extrapolates linearly with aspect ratio as expected. The nanorod orbitals and length dependence agree with a simple particle-in-a-box model. The origins of the transverse and longitudinal peaks are discussed. Similar behavior is also observed for other elongated systems such as nanowires and acenes. A configuration interaction model can be employed to understand the quantum mechanical origin of the plasmon resonance in these systems.

  9. Surface plasmon resonance biosensors: advances and applications

    NASA Astrophysics Data System (ADS)

    Homola, Jirí

    2009-10-01

    Surface plasmon resonance (SPR) biosensors represent the most advanced label-free optical affinity biosensor technology. In the last decade numerous SPR sensor platforms have been developed and applied in the life sciences and bioanalytics. This contribution reviews the state of the art in the development of SPR (bio)sensor technology and presents selected results of research into SPR biosensors at the Institute of Photonics and Electronics, Prague. The developments discussed in detail include a miniature fiber optic SPR sensor for localized measurements, a compact SPR sensor for field use and a multichannel SPR sensor for high-throughput screening. Examples of applications for the detection of analytes related to medical diagnostics (biomarkers, hormones, antibodies), environmental monitoring (endocrine disrupting compounds), and food safety (pathogens and toxins) are given.

  10. On the mechanism of electrochemical modulation of plasmonic resonances

    NASA Astrophysics Data System (ADS)

    Shao, L.-H.; Ruther, M.; Linden, S.; Wegener, M.; Weissmüller, J.

    2012-09-01

    Recent electrochemical experiments on gold-based photonic metamaterials have shown a sizable reversible tuning and modulation of plasmonic resonances. Here, we study the mechanism of the electrochemical modulation by measuring the change of the resonance transmittance and resonance frequency during underpotential deposition of Pb, Cu, and electrosorption of OH. The electric resistance change of the resonators is identified as decisive for the resonance transmittance change, while the space-charge layer at the metal surface shifts the resonance frequency.

  11. Excitation of dark multipolar plasmonic resonances at terahertz frequencies

    PubMed Central

    Chen, Lin; Wei, YuMing; Zang, XiaoFei; Zhu, YiMing; Zhuang, SongLin

    2016-01-01

    We experimentally observe the excitation of dark multipolar spoof localized surface plasmon resonances in a hybrid structure consisting of a corrugated metallic disk coupled with a C-shaped dipole resonator. The uncoupled corrugated metallic disk only supports a dipolar resonance in the transmission spectrum due to perfect symmetry of the structure. However, the dark multipolar spoof localized surface plasmon resonances emerge when coupled with a bright C-shaped resonator which is placed in the vicinity of the corrugated metallic disk. These excited multipolar resonances show minimum influence on the coupling distance between the C-shaped resonator and corrugated metallic disk. The resonance frequencies of the radiative modes are controlled by varying the angle of the C-shaped resonator and the inner disk radius, both of which play dominant roles in the excitation of the spoof localized surface plasmons. Observation of such a transition from the dark to radiative nature of multipolar spoof localized plasmon resonances would find potential applications in terahertz based resonant plasmonic and metamaterial devices. PMID:26903382

  12. Excitation of dark multipolar plasmonic resonances at terahertz frequencies

    NASA Astrophysics Data System (ADS)

    Chen, Lin; Wei, Yuming; Zang, Xiaofei; Zhu, Yiming; Zhuang, Songlin

    2016-02-01

    We experimentally observe the excitation of dark multipolar spoof localized surface plasmon resonances in a hybrid structure consisting of a corrugated metallic disk coupled with a C-shaped dipole resonator. The uncoupled corrugated metallic disk only supports a dipolar resonance in the transmission spectrum due to perfect symmetry of the structure. However, the dark multipolar spoof localized surface plasmon resonances emerge when coupled with a bright C-shaped resonator which is placed in the vicinity of the corrugated metallic disk. These excited multipolar resonances show minimum influence on the coupling distance between the C-shaped resonator and corrugated metallic disk. The resonance frequencies of the radiative modes are controlled by varying the angle of the C-shaped resonator and the inner disk radius, both of which play dominant roles in the excitation of the spoof localized surface plasmons. Observation of such a transition from the dark to radiative nature of multipolar spoof localized plasmon resonances would find potential applications in terahertz based resonant plasmonic and metamaterial devices.

  13. All-plasmonic switching based on thermal nonlinearity in a polymer plasmonic microring resonator

    NASA Astrophysics Data System (ADS)

    Perron, David; Wu, Marcelo; Horvath, Cameron; Bachman, Daniel; van, Vien

    2011-07-01

    We experimentally investigated thermal nonlinear effects in a hybrid Au/SiO2/SU-8 plasmonic microring resonator for nonlinear switching. Large ohmic loss in the metal layer gave rise to a high rate of light-to-heat conversion in the plasmonic waveguide, causing an intensity-dependent thermo-optic shift in the microring resonance. We obtained 30 times larger resonance shift in the plasmonic microring than in a similar SU-8 dielectric microring. Using an in-plane pump-and-probe configuration, we also demonstrated all-plasmonic nonlinear switching in the plasmonic microring with an on--off switching contrast of 4dB over 50mW input power.

  14. Laboratory Experiments for Exploring the Surface Plasmon Resonance

    ERIC Educational Resources Information Center

    Pluchery, Olivier; Vayron, Romain; Van, Kha-Man

    2011-01-01

    The surface plasmon wave is a surface wave confined at the interface between a dielectric and a metal. The excitation of the surface plasmon resonance (SPR) on a gold thin film is discussed within the Kretschmann configuration, where the coupling with the excitation light is achieved by means of a prism in total reflection. The electromagnetic…

  15. Resonant Scattering of Surface Plasmon Polaritons by Dressed Quantum Dots

    DTIC Science & Technology

    2014-06-23

    Resonant scattering of surface plasmon polaritons by dressed quantum dots Danhong Huang,1 Michelle Easter,2 Godfrey Gumbs,3 A. A. Maradudin,4 Shawn... polariton waves (SPP) by embedded semiconductor quantum dots above the dielectric/metal interface is explored in the strong-coupling regime. In con- trast to...induced polarization field, treated as a source term9 arising from photo-excited electrons, allows for a resonant scattering of surface plasmon- polariton

  16. Electron energy-loss spectroscopy of branched gap plasmon resonators

    PubMed Central

    Raza, Søren; Esfandyarpour, Majid; Koh, Ai Leen; Mortensen, N. Asger; Brongersma, Mark L.; Bozhevolnyi, Sergey I.

    2016-01-01

    The miniaturization of integrated optical circuits below the diffraction limit for high-speed manipulation of information is one of the cornerstones in plasmonics research. By coupling to surface plasmons supported on nanostructured metallic surfaces, light can be confined to the nanoscale, enabling the potential interface to electronic circuits. In particular, gap surface plasmons propagating in an air gap sandwiched between metal layers have shown extraordinary mode confinement with significant propagation length. In this work, we unveil the optical properties of gap surface plasmons in silver nanoslot structures with widths of only 25 nm. We fabricate linear, branched and cross-shaped nanoslot waveguide components, which all support resonances due to interference of counter-propagating gap plasmons. By exploiting the superior spatial resolution of a scanning transmission electron microscope combined with electron energy-loss spectroscopy, we experimentally show the propagation, bending and splitting of slot gap plasmons. PMID:27982030

  17. Electron energy-loss spectroscopy of branched gap plasmon resonators

    NASA Astrophysics Data System (ADS)

    Raza, Søren; Esfandyarpour, Majid; Koh, Ai Leen; Mortensen, N. Asger; Brongersma, Mark L.; Bozhevolnyi, Sergey I.

    2016-12-01

    The miniaturization of integrated optical circuits below the diffraction limit for high-speed manipulation of information is one of the cornerstones in plasmonics research. By coupling to surface plasmons supported on nanostructured metallic surfaces, light can be confined to the nanoscale, enabling the potential interface to electronic circuits. In particular, gap surface plasmons propagating in an air gap sandwiched between metal layers have shown extraordinary mode confinement with significant propagation length. In this work, we unveil the optical properties of gap surface plasmons in silver nanoslot structures with widths of only 25 nm. We fabricate linear, branched and cross-shaped nanoslot waveguide components, which all support resonances due to interference of counter-propagating gap plasmons. By exploiting the superior spatial resolution of a scanning transmission electron microscope combined with electron energy-loss spectroscopy, we experimentally show the propagation, bending and splitting of slot gap plasmons.

  18. Frequency-selective propagation of localized spoof surface plasmons in a graded plasmonic resonator chain

    PubMed Central

    Gao, Zhen; Gao, Fei; Shastri, Kunal Krishnaraj; Zhang, Baile

    2016-01-01

    Localized spoof surface plasmon polaritons (spoof-SPPs) in a graded spoof-plasmonic resonator chain with linearly increasing spacing are experimentally investigated at microwave frequencies. Transmission measurements and direct near-field mappings on this graded chain show that the propagation of localized spoof-SPPs can be cutoff at different positions along the graded chain under different frequencies due to the graded coupling between adjacent resonators. This mechanism can be used to guide localized spoof-SPPs in the graded chain to specific positions depending on the frequency and thereby implement a device that can work as a selective switch in integrated plasmonic circuits. PMID:27149656

  19. Interacting dark resonances with plasmonic meta-molecules

    SciTech Connect

    Jha, Pankaj K.; Mrejen, Michael; Kim, Jeongmin; Wu, Chihhui; Yin, Xiaobo; Wang, Yuan; Zhang, Xiang

    2014-09-15

    Dark state physics has led to a variety of remarkable phenomena in atomic physics, quantum optics, and information theory. Here, we investigate interacting dark resonance type physics in multi-layered plasmonic meta-molecules. We theoretically demonstrate that these plasmonic meta-molecules exhibit sub-natural spectral response, analogous to conventional atomic four-level configuration, by manipulating the evanescent coupling between the bright and dark elements (plasmonic atoms). Using cascaded coupling, we show nearly 4-fold reduction in linewidth of the hybridized resonance compared to a resonantly excited single bright plasmonic atom with same absorbance. In addition, we engineered the geometry of the meta-molecules to realize efficient intramolecular excitation transfer with nearly 80%, on resonant excitation, of the total absorption being localized at the second dark plasmonic atom. An analytical description of the spectral response of the structure is presented with full electrodynamics simulations to corroborate our results. Such multilayered meta-molecules can bring a new dimension to higher quality factor plasmonic resonance, efficient excitation transfer, wavelength demultiplexing, and enhanced non-linearity at nanoscale.

  20. Synthesis and characterization of plasmonic resonant guided wave networks.

    PubMed

    Burgos, Stanley P; Lee, Ho W; Feigenbaum, Eyal; Briggs, Ryan M; Atwater, Harry A

    2014-06-11

    Composed of optical waveguides and power-splitting waveguide junctions in a network layout, resonant guided wave networks (RGWNs) split an incident wave into partial waves that resonantly interact within the network. Resonant guided wave networks have been proposed as nanoscale distributed optical networks (Feigenbaum and Atwater, Phys. Rev. Lett. 2010, 104, 147402) that can function as resonators and color routers (Feigenbaum et al. Opt. Express 2010, 18, 25584-25595). Here we experimentally characterize a plasmonic resonant guided wave network by demonstrating that a 90° waveguide junction of two v-groove channel plasmon polariton (CPP) waveguides operates as a compact power-splitting element. Combining these plasmonic power splitters with CPP waveguides in a network layout, we characterize a prototype plasmonic nanocircuit composed of four v-groove waveguides in an evenly spaced 2 × 2 configuration, which functions as a simple, compact optical logic device at telecommunication wavelengths, routing different wavelengths to separate transmission ports due to the resulting network resonances. The resonant guided wave network exhibits the full permutation of Boolean on/off values at two output ports and can be extended to an eight-port configuration, unlike other photonic crystal and plasmonic add/drop filters, in which only two on/off states are accessible.

  1. Small Molecule Immunosensing Using Surface Plasmon Resonance

    PubMed Central

    Mitchell, John

    2010-01-01

    Surface plasmon resonance (SPR) biosensors utilize refractive index changes to sensitively detect mass changes at noble metal sensor surface interfaces. As such, they have been extensively applied to immunoassays of large molecules, where their high mass and use of sandwich immunoassay formats can result in excellent sensitivity. Small molecule immunosensing using SPR is more challenging. It requires antibodies or high-mass or noble metal labels to provide the required signal for ultrasensitive assays. Also, it can suffer from steric hindrance between the small antigen and large antibodies. However, new studies are increasingly meeting these and other challenges to offer highly sensitive small molecule immunosensor technologies through careful consideration of sensor interface design and signal enhancement. This review examines the application of SPR transduction technologies to small molecule immunoassays directed to different classes of small molecule antigens, including the steroid hormones, toxins, drugs and explosives residues. Also considered are the matrix effects resulting from measurement in chemically complex samples, the construction of stable sensor surfaces and the development of multiplexed assays capable of detecting several compounds at once. Assay design approaches are discussed and related to the sensitivities obtained. PMID:22163605

  2. Surface plasmon resonance immunosensor for bacteria detection.

    PubMed

    Baccar, H; Mejri, M B; Hafaiedh, I; Ktari, T; Aouni, M; Abdelghani, A

    2010-07-15

    This work describes an approach for the development of two bacteria biosensors based on surface plasmon resonance (SPR) technique. The first biosensor was based on functionalized gold substrate and the second one on immobilized gold nanoparticles. For the first biosensor, the gold substrate was functionalized with acid-thiol using the self-assembled monolayer technique, while the second one was functionalized with gold nanoparticles immobilized on modified gold substrate. A polyclonal anti-Escherichia coli antibody was immobilized for specific (E. coli) and non-specific (Lactobacillus) bacteria detection. Detection limit with a good reproducibility of 10(4) and 10(3) cfu mL(-1) of E. coli bacteria has been obtained for the first biosensor and for the second one respectively. A refractive index variation below 5x10(-3) due to bacteria adsorption is able to be detected. The refractive index of the multilayer structure and of the E. coli bacteria layer was estimated with a modeling software.

  3. Culturing photosynthetic bacteria through surface plasmon resonance

    SciTech Connect

    Ooms, Matthew D.; Bajin, Lauren; Sinton, David

    2012-12-17

    In this work, cultivation of photosynthetic microbes in surface plasmon enhanced evanescent fields is demonstrated. Proliferation of Synechococcus elongatus was obtained on gold surfaces excited with surface plasmons. Excitation over three days resulted in 10 {mu}m thick biofilms with maximum cell volume density of 20% vol/vol (2% more total accumulation than control experiments with direct light). Collectively, these results indicate the ability to (1) excite surface-bound cells using plasmonic light fields, and (2) subsequently grow thick biofilms by coupling light from the surface. Plasmonic light delivery presents opportunities for high-density optofluidic photobioreactors for microalgal analysis and solar fuel production.

  4. Culturing photosynthetic bacteria through surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Ooms, Matthew D.; Bajin, Lauren; Sinton, David

    2012-12-01

    In this work, cultivation of photosynthetic microbes in surface plasmon enhanced evanescent fields is demonstrated. Proliferation of Synechococcus elongatus was obtained on gold surfaces excited with surface plasmons. Excitation over three days resulted in 10 μm thick biofilms with maximum cell volume density of 20% vol/vol (2% more total accumulation than control experiments with direct light). Collectively, these results indicate the ability to (1) excite surface-bound cells using plasmonic light fields, and (2) subsequently grow thick biofilms by coupling light from the surface. Plasmonic light delivery presents opportunities for high-density optofluidic photobioreactors for microalgal analysis and solar fuel production.

  5. Optics and biophotonics of nanoparticles with a plasmon resonance

    SciTech Connect

    Khlebtsov, N G

    2008-06-30

    A brief review of the state of the art in theoretical and experimental studies of the optical properties of metal particles with dipole and multipole plasmon resonances is presented. Metal spheres, nanorods, spherical and elliptic metal nanoshells are considered. The tuning of plasmon resonances of nanoparticles by varying their size, shape, structure, and dielectric environment is described. A large amount of spectrophotometric data on dimensional characteristics of gold colloidal particles is critically analysed and a new calibration of the dependence of their average size on the extinction plasmon resonance wavelength is proposed. A drastic difference between gold and silver colloids in the region of small deviations of their form from spherical is discussed. An example of the excess over not only the Rayleigh limit for the scattering depolarisation factor for dielectric needles (1/3) but also over the plasmon-resonance limit for metal thin rods (3/4) is presented for the first time. The multipole properties of nanorods and universal linear wavelength scaling of multipole resonances are considered depending on the axial ratio of nanoparticles. The outlook for modern trends in biomedical applications of nanoparticles with plasmon resonances is discussed. (special issue devoted to application of laser technologies in biophotonics and biomedical studies)

  6. Broadband converging plasmon resonance at a conical nanotip.

    PubMed

    Wang, Yunshan; Plouraboue, Franck; Chang, Hsueh-Chia

    2013-03-11

    We propose an analytical theory which predicts that Converging Plasmon Resonance (CPR) at conical nanotips exhibits a red-shifted and continuous band of resonant frequencies and suggests potential application of conical nanotips in various fields, such as plasmonic solar cells, photothermal therapy, tip-enhanced Raman and other spectroscopies. The CPR modes exhibit superior confinement and ten times broader scattering bandwidth over the entire solar spectrum than smooth nano-structures. The theory also explicitly connects the optimal angles and resonant optical frequencies to the material permittivities, with a specific optimum half angle that depends only on the real permittivity for high-permittivity and low-loss materials.

  7. Nanoparticle plasmon resonances in the near-static limit.

    PubMed

    Pedersen, Thomas G; Jung, Jesper; Søndergaard, Thomas; Pedersen, Kjeld

    2011-03-01

    Localized surface plasmon resonances of metal nanoparticles of arbitrary shape are analyzed in the near-static limit with retardation included to the second order. Starting from the electrostatic approximation, the second-order correction to the resonant dielectric constant is expressed by means of a triple surface integral. For arbitrary nanoparticles with cylindrical symmetry we show how the triple surface integral can be significantly simplified, resulting in a computationally efficient scheme for evaluation of nanoparticle plasmon eigenresonances in the near-static limit. The approach allows for calculation of both dipolar and higher-order resonances.

  8. Charge Transfer Plasmons: Optical Frequency Conductances and Tunable Infrared Resonances.

    PubMed

    Wen, Fangfang; Zhang, Yue; Gottheim, Samuel; King, Nicholas S; Zhang, Yu; Nordlander, Peter; Halas, Naomi J

    2015-06-23

    A charge transfer plasmon (CTP) appears when an optical-frequency conductive pathway between two metallic nanoparticles is established, enabling the transfer of charge between nanoparticles when the plasmon is excited. Here we investigate the properties of the CTP in a nanowire-bridged dimer geometry. Varying the junction geometry controls its conductance, which modifies the resonance energies and scattering intensities of the CTP while also altering the other plasmon modes of the nanostructure. Reducing the junction conductance shifts this resonance to substantially lower energies in the near- and mid-infrared regions of the spectrum. The CTP offers both a high-information probe of optical frequency conductances in nanoscale junctions and a new, unique approach to controllably engineering tunable plasmon modes at infrared wavelengths.

  9. Spoof localized surface plasmons on ultrathin textured MIM ring resonator with enhanced resonances.

    PubMed

    Zhou, Yong Jin; Xiao, Qian Xun; Yang, Bao Jia

    2015-09-30

    We numerically demonstrate that spoof localized surface plasmons (LSPs) resonant modes can be enhanced based on ultrathin corrugated metal-insulator-metal (MIM) ring resonator. Further enhancement of the LSPs modes has been achieved by incorporating an efficient and ease-of-integration exciting method. Quality factors of resonance peaks have become much larger and multipolar resonances modes can be easily observed on the textured MIM ring resonator excited by a microstrip line. Experimental results validate the high-efficiency excitation and resonance enhancements of spoof LSPs modes on the MIM ring resonator in the microwave frequencies. We have shown that the fabricated resonator is sensitive to the variation of both the dielectric constant and the thickness of surrounding materials under test. The spoof plasmonic resonator can be used as key elements to provide many important device functionalities such as optical communications, signal processing, and spectral engineering in the plasmonic integration platform.

  10. Spoof localized surface plasmons on ultrathin textured MIM ring resonator with enhanced resonances

    PubMed Central

    Zhou, Yong Jin; Xiao, Qian Xun; Jia Yang, Bao

    2015-01-01

    We numerically demonstrate that spoof localized surface plasmons (LSPs) resonant modes can be enhanced based on ultrathin corrugated metal-insulator-metal (MIM) ring resonator. Further enhancement of the LSPs modes has been achieved by incorporating an efficient and ease-of-integration exciting method. Quality factors of resonance peaks have become much larger and multipolar resonances modes can be easily observed on the textured MIM ring resonator excited by a microstrip line. Experimental results validate the high-efficiency excitation and resonance enhancements of spoof LSPs modes on the MIM ring resonator in the microwave frequencies. We have shown that the fabricated resonator is sensitive to the variation of both the dielectric constant and the thickness of surrounding materials under test. The spoof plasmonic resonator can be used as key elements to provide many important device functionalities such as optical communications, signal processing, and spectral engineering in the plasmonic integration platform. PMID:26420668

  11. Plasmonic metalens based on coupled resonators for focusing of surface plasmons

    NASA Astrophysics Data System (ADS)

    Xu, Quan; Zhang, Xueqian; Xu, Yuehong; Li, Quan; Li, Yanfeng; Ouyang, Chunmei; Tian, Zhen; Gu, Jianqiang; Zhang, Wentao; Zhang, Xixiang; Han, Jiaguang; Zhang, Weili

    2016-11-01

    As an essential functionality, flexible focusing of surface plasmons (SPs) is of particular interest in nonlinear optics and highly integrated plasmonic circuitry. Here, we developed a versatile plasmonic metalens, a metasurface comprised of coupled subwavelength resonators, whose optical responses exhibit a remarkable feature of electromagnetically induced transparency (EIT). We demonstrate numerically and experimentally how a proper spatial design of the unit elements steers SPs to arbitrary foci based on the holographic principles. More specifically, we show how to control the interaction between the constituent EIT resonators to efficiently manipulate the focusing intensity of SPs. We also demonstrated that the proposed metalens is capable of achieving frequency division multiplexing. The power and simplicity of the proposed design would offer promising opportunities for practical plasmonic devices.

  12. Plasmonic metalens based on coupled resonators for focusing of surface plasmons

    PubMed Central

    Xu, Quan; Zhang, Xueqian; Xu, Yuehong; Li, Quan; Li, Yanfeng; Ouyang, Chunmei; Tian, Zhen; Gu, Jianqiang; Zhang, Wentao; Zhang, Xixiang; Han, Jiaguang; Zhang, Weili

    2016-01-01

    As an essential functionality, flexible focusing of surface plasmons (SPs) is of particular interest in nonlinear optics and highly integrated plasmonic circuitry. Here, we developed a versatile plasmonic metalens, a metasurface comprised of coupled subwavelength resonators, whose optical responses exhibit a remarkable feature of electromagnetically induced transparency (EIT). We demonstrate numerically and experimentally how a proper spatial design of the unit elements steers SPs to arbitrary foci based on the holographic principles. More specifically, we show how to control the interaction between the constituent EIT resonators to efficiently manipulate the focusing intensity of SPs. We also demonstrated that the proposed metalens is capable of achieving frequency division multiplexing. The power and simplicity of the proposed design would offer promising opportunities for practical plasmonic devices. PMID:27897221

  13. Metal nanoparticles with sharp corners: Universal properties of plasmon resonances

    NASA Astrophysics Data System (ADS)

    Sturman, B.; Podivilov, E.; Gorkunov, M.

    2013-03-01

    We predict the simultaneous occurrence of two fundamental phenomena for metal nanoparticles possessing sharp corners with variable curvature: First, the main dipolar plasmonic mode experiences a strong red shift with increasing corner curvature; for large values of the curvature, the resonant frequency is controlled by the apex angle of the corner. Second, the split-off plasmonic mode experiences a strong localization at the corners. Altogether, this paves the way for the tailoring of metal nanostructures providing a wavelength-selective excitation of localized plasmons and a strong near-field enhancement of linear and nonlinear optical phenomena.

  14. Plasmon-induced resonance energy transfer for solar energy conversion

    NASA Astrophysics Data System (ADS)

    Li, Jiangtian; Cushing, Scott K.; Meng, Fanke; Senty, Tess R.; Bristow, Alan D.; Wu, Nianqiang

    2015-09-01

    In Förster resonance energy transfer (FRET), energy non-radiatively transfers from a blue-shifted emitter to a red-shifted absorber by dipole-dipole coupling. This study shows that plasmonics enables the opposite transfer direction, transferring the plasmonic energy towards the short-wavelength direction to induce charge separation in a semiconductor. Plasmon-induced resonance energy transfer (PIRET) differs from FRET because of the lack of a Stoke's shift, non-local absorption effects and a strong dependence on the plasmon's dephasing rate and dipole moment. PIRET non-radiatively transfers energy through an insulating spacer layer, which prevents interfacial charge recombination losses and dephasing of the plasmon from hot-electron transfer. The distance dependence of dipole-dipole coupling is mapped out for a range of detuning across the plasmon resonance. PIRET can efficiently harvest visible and near-infrared sunlight with energy below the semiconductor band edge to help overcome the constraints of band-edge energetics for single semiconductors in photoelectrochemical cells, photocatalysts and photovoltaics.

  15. Localized Surface Plasmon Resonance Biosensing: Current Challenges and Approaches

    PubMed Central

    Unser, Sarah; Bruzas, Ian; He, Jie; Sagle, Laura

    2015-01-01

    Localized surface plasmon resonance (LSPR) has emerged as a leader among label-free biosensing techniques in that it offers sensitive, robust, and facile detection. Traditional LSPR-based biosensing utilizes the sensitivity of the plasmon frequency to changes in local index of refraction at the nanoparticle surface. Although surface plasmon resonance technologies are now widely used to measure biomolecular interactions, several challenges remain. In this article, we have categorized these challenges into four categories: improving sensitivity and limit of detection, selectivity in complex biological solutions, sensitive detection of membrane-associated species, and the adaptation of sensing elements for point-of-care diagnostic devices. The first section of this article will involve a conceptual discussion of surface plasmon resonance and the factors affecting changes in optical signal detected. The following sections will discuss applications of LSPR biosensing with an emphasis on recent advances and approaches to overcome the four limitations mentioned above. First, improvements in limit of detection through various amplification strategies will be highlighted. The second section will involve advances to improve selectivity in complex media through self-assembled monolayers, “plasmon ruler” devices involving plasmonic coupling, and shape complementarity on the nanoparticle surface. The following section will describe various LSPR platforms designed for the sensitive detection of membrane-associated species. Finally, recent advances towards multiplexed and microfluidic LSPR-based devices for inexpensive, rapid, point-of-care diagnostics will be discussed. PMID:26147727

  16. Tuneable and robust long range surface plasmon resonance for biosensing applications

    NASA Astrophysics Data System (ADS)

    Méjard, Régis; Dostálek, Jakub; Huang, Chun-Jen; Griesser, Hans; Thierry, Benjamin

    2013-10-01

    A multilayered biosensing architecture based on long range surface plasmons (LRSPs) is reported. LRSPs originate from the coupling of surface plasmons on the opposite sides of a thin metal film embedded in a symmetrical refractive index environment. With respect to regular SPs, LRSPs are characterized by extended electromagnetic field profiles and lower losses, making them of high interest in biosensing, especially for large biological entities. LRSPs-supporting layer structures are typically prepared by using fluoropolymers with refractive indices close to that of water. Unfortunately, fluoropolymers have low surface energies which can translate into poor adhesion to substrates and sub-optimal properties of coatings with surface plasmon resonance-active metal layers such as gold. In this work, a multilayered fluoropolymer structure with tuneable average refractive index is described and used to adjust the penetration depth of LRSP from the sensor surface. The proposed methodology also provides a simple solution to increase the adhesion of LRSP-supporting structures to glass substrates. Towards taking full advantage of long range surface plasmon resonance sensors, a novel approach based on the plasma-polymerization of allylamine is also described to improve the quality of gold layers on fluoropolymers such as Teflon AF. Through these advancements, long range surface plasmon resonance sensors were fabricated with figures of merit as high as 466 RIU-1. The remarkable performance of these sensors combined with their high stability is expected to foster applications of LRSPR in biosensing.

  17. Surface Plasmon Resonance: A Versatile Technique for Biosensor Applications

    PubMed Central

    Nguyen, Hoang Hiep; Park, Jeho; Kang, Sebyung; Kim, Moonil

    2015-01-01

    Surface plasmon resonance (SPR) is a label-free detection method which has emerged during the last two decades as a suitable and reliable platform in clinical analysis for biomolecular interactions. The technique makes it possible to measure interactions in real-time with high sensitivity and without the need of labels. This review article discusses a wide range of applications in optical-based sensors using either surface plasmon resonance (SPR) or surface plasmon resonance imaging (SPRI). Here we summarize the principles, provide examples, and illustrate the utility of SPR and SPRI through example applications from the biomedical, proteomics, genomics and bioengineering fields. In addition, SPR signal amplification strategies and surface functionalization are covered in the review. PMID:25951336

  18. Quantum electrodynamics and plasmonic resonance of metallic nanostructures.

    PubMed

    Zhang, Mingliang; Xiang, Hongping; Zhang, Xu; Lu, Gang

    2016-04-20

    Plasmonic resonance of a metallic nanostructure results from coherent motion of its conduction electrons driven by incident light. At the resonance, the induced dipole in the nanostructure is proportional to the number of the conduction electrons, hence 10(7) times larger than that in an atom. The interaction energy between the induced dipole and fluctuating virtual field of the incident light can reach a few tenths of an eV. Therefore, the classical electromagnetism dominating the field may become inadequate. We propose that quantum electrodynamics (QED) may be used as a fundamental theory to describe the interaction between the virtual field and the oscillating electrons. Based on QED, we derive analytic expressions for the plasmon resonant frequency, which depends on three easily accessible material parameters. The analytic theory reproduces very well the experimental data, and can be used in rational design of materials for plasmonic applications.

  19. Surface Plasmon Resonance-Induced Stiffening of Silver Nanowires

    PubMed Central

    Ben, Xue; Park, Harold S.

    2015-01-01

    We report the results of a computational, atomistic electrodynamics study of the effects of electromagnetic waves on the mechanical properties, and specifically the Young’s modulus of silver nanowires. We find that the Young’s modulus of the nanowires is strongly dependent on the optical excitation energy, with a peak enhancement occurring at the localized surface plasmon resonance frequency. When the nanowire is excited at the plasmon resonance frequency, the Young’s modulus is found to increase linearly with increasing nanowire aspect ratio, with a stiffening of nearly 15% for a 2 nm cross section silver nanowire with an aspect ratio of 3.5. Furthermore, our results suggest that this plasmon resonance-induced stiffening is stronger for larger diameter nanowires for a given aspect ratio. Our study demonstrates a novel approach to actively tailoring and enhancing the mechanical properties of metal nanowires. PMID:26024426

  20. Noble metal nanostructures for double plasmon resonance with tunable properties

    NASA Astrophysics Data System (ADS)

    Petr, M.; Kylián, O.; Kuzminova, A.; Kratochvíl, J.; Khalakhan, I.; Hanuš, J.; Biederman, H.

    2017-02-01

    We report and compare two vacuum-based strategies to produce Ag/Au materials characterized by double plasmon resonance peaks: magnetron sputtering and method based on the use of gas aggregation sources (GAS) of nanoparticles. It was observed that the double plasmon resonance peaks may be achieved by both of these methods and that the intensities of individual localized surface plasmon resonance peaks may be tuned by deposition conditions. However, in the case of sputter deposition it was necessary to introduce a separation dielectric interlayer in between individual Ag and Au nanoparticle films which was not the case of films prepared by GAS systems. The differences in the optical properties of sputter deposited bimetallic Ag/Au films and coatings consisted of individual Ag and Au nanoparticles produced by GAS is ascribed to the divers mechanisms of nanoparticles formation.

  1. Electron beam imaging and spectroscopy of plasmonic nanoantenna resonances

    NASA Astrophysics Data System (ADS)

    Vesseur, E. J. R.

    2011-07-01

    Nanoantennas are metal structures that provide strong optical coupling between a nanoscale volume and the far field. This coupling is mediated by surface plasmons, oscillations of the free electrons in the metal. Increasing the control over the resonant plasmonic field distribution opens up a wide range of applications of nanoantennas operating both in receiving and transmitting mode. This thesis presents how the dispersion and confinement of surface plasmons in nanoantennas are resolved and further engineered. Fabrication of nanostructures is done using focused ion beam milling (FIB) in metallic surfaces. We demonstrate that patterning in single-crystal substrates allows us to precisely control the geometry in which plasmons are confined. The nanoscale properties of the resonant plasmonic fields are resolved using a new technique developed in this thesis: angle- and polarization controlled cathodoluminescence (CL) imaging spectroscopy. The use of a tightly focused electron beam allows us to probe the optical antenna properties with deep subwavelength resolution. We show using this technique that nanoantennas consisting of 500-1200 nm long polycrystalline Au nanowires support standing plasmon waves. We directly observe the plasmon wavelengths which we use to derive the dispersion relation of guided nanowire plasmons. A 590-nm-long ridge-shaped nanoantenna was fabricated using FIB milling on a single-crystal Au substrate, demonstrating a level of control over the fabrication impossible with polycrystalline metals. CL experiments show that the ridge supports multiple-order resonances. The confinement of surface plasmons to the ridge is confirmed by boundary-element-method (BEM) calculations. The resonant modes in plasmonic whispering gallery cavities consisting of a FIB-fabricated circular groove are resolved. We find an excellent agreement between boundary element method calculations and the measured CL emission from the ring-shaped cavities. The calculations show

  2. Surface Plasmon Resonance Evaluation of Colloidal Metal Aerogel Filters

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Sibille, Laurent; Cronise, Raymond J.; Noever, David A.

    1997-01-01

    Surface plasmon resonance imaging has in the past been applied to the characterization of thin films. In this study we apply the surface plasmon technique not to determine macroscopic spatial variations but rather to determine average microscopic information. Specifically, we deduce the dielectric properties of the surrounding gel matrix and information concerning the dynamics of the gelation process from the visible absorption characteristics of colloidal metal nanoparticles contained in aerogel pores. We have fabricated aerogels containing gold and silver nanoparticles. Because the dielectric constant of the metal particles is linked to that of the host matrix at the surface plasmon resonance, any change 'in the dielectric constant of the material surrounding the metal nanoparticles results in a shift in the surface plasmon wavelength. During gelation the surface plasmon resonance shifts to the red as the average or effective dielectric constant of the matrix increases. Conversely, formation of an aerogel or xerogel through supercritical extraction or evaporation of the solvent produces a blue shift in the resonance indicating a decrease in the dielectric constant of the matrix. From the magnitude of this shift we deduce the average fraction of air and of silica in contact with the metal particles. The surface area of metal available for catalytic gas reaction may thus be determined.

  3. Polarization-selective dynamically tunable multispectral Fano resonances: decomposing of subgroup plasmonic resonances.

    PubMed

    Liu, Jietao; Zhao, Xiaoliang; Gong, Rui; Wu, Tengfei; Gong, Changmei; Shao, Xiaopeng

    2015-10-19

    We analyze the design of near infrared all-optical controllable and dynamically tunable multispectral Fano resonances based on subgroup decomposition of plasmonic resonances in hybrid nanoslits antenna plasmonic system. The theoretical investigation complemented with numerical simulations show that the Fano resonance lines shape can be tailored efficiently and continuously with the nanoslits geometry and the variation of the polarization states of the incident light. The subgroup decomposition of the spectral profile and the modification of plasmonic resonances lineshape that leads to the Fano-type profile of transmission is investigated and revealed. The separate contribution from individual spectral of single-slit array subgroup is attributed to the resulting overall multispectral Fano lineshape of the proposed T-shaped slits array at their corresponding spectral peaks zone. The polarization-selective tunability of the multispectral Fano resonances in the planar hybrid plasmonic system creates new avenues for designing multi-channel multi-wavelength tunable Fano effect.

  4. Frequency comb transferred by surface plasmon resonance.

    PubMed

    Geng, Xiao Tao; Chun, Byung Jae; Seo, Ji Hoon; Seo, Kwanyong; Yoon, Hana; Kim, Dong-Eon; Kim, Young-Jin; Kim, Seungchul

    2016-02-22

    Frequency combs, millions of narrow-linewidth optical modes referenced to an atomic clock, have shown remarkable potential in time/frequency metrology, atomic/molecular spectroscopy and precision LIDARs. Applications have extended to coherent nonlinear Raman spectroscopy of molecules and quantum metrology for entangled atomic qubits. Frequency combs will create novel possibilities in nano-photonics and plasmonics; however, its interrelation with surface plasmons is unexplored despite the important role that plasmonics plays in nonlinear spectroscopy and quantum optics through the manipulation of light on a subwavelength scale. Here, we demonstrate that a frequency comb can be transformed to a plasmonic comb in plasmonic nanostructures and reverted to the original frequency comb without noticeable degradation of <6.51 × 10(-19) in absolute position, 2.92 × 10(-19) in stability and 1 Hz in linewidth. The results indicate that the superior performance of a well-defined frequency comb can be applied to nanoplasmonic spectroscopy, quantum metrology and subwavelength photonic circuits.

  5. Frequency comb transferred by surface plasmon resonance

    PubMed Central

    Geng, Xiao Tao; Chun, Byung Jae; Seo, Ji Hoon; Seo, Kwanyong; Yoon, Hana; Kim, Dong-Eon; Kim, Young-Jin; Kim, Seungchul

    2016-01-01

    Frequency combs, millions of narrow-linewidth optical modes referenced to an atomic clock, have shown remarkable potential in time/frequency metrology, atomic/molecular spectroscopy and precision LIDARs. Applications have extended to coherent nonlinear Raman spectroscopy of molecules and quantum metrology for entangled atomic qubits. Frequency combs will create novel possibilities in nano-photonics and plasmonics; however, its interrelation with surface plasmons is unexplored despite the important role that plasmonics plays in nonlinear spectroscopy and quantum optics through the manipulation of light on a subwavelength scale. Here, we demonstrate that a frequency comb can be transformed to a plasmonic comb in plasmonic nanostructures and reverted to the original frequency comb without noticeable degradation of <6.51 × 10−19 in absolute position, 2.92 × 10−19 in stability and 1 Hz in linewidth. The results indicate that the superior performance of a well-defined frequency comb can be applied to nanoplasmonic spectroscopy, quantum metrology and subwavelength photonic circuits. PMID:26898307

  6. Sensing (un)binding events via surface plasmons: effects of resonator geometry

    NASA Astrophysics Data System (ADS)

    Antosiewicz, Tomasz J.; Claudio, Virginia; Käll, Mikael

    2016-04-01

    The resonance conditions of localized surface plasmon resonances (LSPRs) can be perturbed in any number ways making plasmon nanoresonators viable tools in detection of e.g. phase changes, pH, gasses, and single molecules. Precise measurement via LSPR of molecular concentrations hinge on the ability to confidently count the number of molecules attached to a metal resonator and ideally to track binding and unbinding events in real-time. These two requirements make it necessary to rigorously quantify relations between the number of bound molecules and response of plasmonic sensors. This endeavor is hindered on the one hand by a spatially varying response of a given plasmonic nanosensor. On the other hand movement of molecules is determined by stochastic effects (Brownian motion) as well as deterministic flow, if present, in microfluidic channels. The combination of molecular dynamics and the electromagnetic response of the LSPR yield an uncertainty which is little understood and whose effect is often disregarded in quantitative sensing experiments. Using a combination of electromagnetic finite-difference time-domain (FDTD) calculations of the plasmon resonance peak shift of various metal nanosensors (disk, cone, rod, dimer) and stochastic diffusion-reaction simulations of biomolecular interactions on a sensor surface we clarify the interplay between position dependent binding probability and inhomogeneous sensitivity distribution. We show, how the statistical characteristics of the total signal upon molecular binding are determined. The proposed methodology is, in general, applicable to any sensor and any transduction mechanism, although the specifics of implementation will vary depending on circumstances. In this work we focus on elucidating how the interplay between electromagnetic and stochastic effects impacts the feasibility of employing particular shapes of plasmonic sensors for real-time monitoring of individual binding reactions or sensing low concentrations

  7. Plasmon coupling in vertical split-ring resonator metamolecules.

    PubMed

    Wu, Pin Chieh; Hsu, Wei-Lun; Chen, Wei Ting; Huang, Yao-Wei; Liao, Chun Yen; Liu, Ai Qun; Zheludev, Nikolay I; Sun, Greg; Tsai, Din Ping

    2015-06-05

    The past decade has seen a number of interesting designs proposed and implemented to generate artificial magnetism at optical frequencies using plasmonic metamaterials, but owing to the planar configurations of typically fabricated metamolecules that make up the metamaterials, the magnetic response is mainly driven by the electric field of the incident electromagnetic wave. We recently fabricated vertical split-ring resonators (VSRRs) which behave as magnetic metamolecules sensitive to both incident electric and magnetic fields with stronger induced magnetic dipole moment upon excitation in comparison to planar SRRs. The fabrication technique enabled us to study the plasmon coupling between VSRRs that stand up side by side where the coupling strength can be precisely controlled by varying the gap in between. The resulting wide tuning range of these resonance modes offers the possibility of developing frequency selective functional devices such as sensors and filters based on plasmon coupling with high sensitivity.

  8. Non-blinking quantum dot with a plasmonic nanoshell resonator

    NASA Astrophysics Data System (ADS)

    Ji, Botao; Giovanelli, Emerson; Habert, Benjamin; Spinicelli, Piernicola; Nasilowski, Michel; Xu, Xiangzhen; Lequeux, Nicolas; Hugonin, Jean-Paul; Marquier, Francois; Greffet, Jean-Jacques; Dubertret, Benoit

    2015-02-01

    Colloidal semiconductor quantum dots are fluorescent nanocrystals exhibiting exceptional optical properties, but their emission intensity strongly depends on their charging state and local environment. This leads to blinking at the single-particle level or even complete fluorescence quenching, and limits the applications of quantum dots as fluorescent particles. Here, we show that a single quantum dot encapsulated in a silica shell coated with a continuous gold nanoshell provides a system with a stable and Poissonian emission at room temperature that is preserved regardless of drastic changes in the local environment. This novel hybrid quantum dot/silica/gold structure behaves as a plasmonic resonator with a strong Purcell factor, in very good agreement with simulations. The gold nanoshell also acts as a shield that protects the quantum dot fluorescence and enhances its resistance to high-power photoexcitation or high-energy electron beams. This plasmonic fluorescent resonator opens the way to a new family of plasmonic nanoemitters with robust optical properties.

  9. Plasmonic piezoelectric nanomechanical resonator for spectrally selective infrared sensing

    PubMed Central

    Hui, Yu; Gomez-Diaz, Juan Sebastian; Qian, Zhenyun; Alù, Andrea; Rinaldi, Matteo

    2016-01-01

    Ultrathin plasmonic metasurfaces have proven their ability to control and manipulate light at unprecedented levels, leading to exciting optical functionalities and applications. Although to date metasurfaces have mainly been investigated from an electromagnetic perspective, their ultrathin nature may also provide novel and useful mechanical properties. Here we propose a thin piezoelectric plasmonic metasurface forming the resonant body of a nanomechanical resonator with simultaneously tailored optical and electromechanical properties. We experimentally demonstrate that it is possible to achieve high thermomechanical coupling between electromagnetic and mechanical resonances in a single ultrathin piezoelectric nanoplate. The combination of nanoplasmonic and piezoelectric resonances allows the proposed device to selectively detect long-wavelength infrared radiation with unprecedented electromechanical performance and thermal capabilities. These attributes lead to the demonstration of a fast, high-resolution, uncooled infrared detector with ∼80% absorption for an optimized spectral bandwidth centered around 8.8 μm. PMID:27080018

  10. Surface Plasmon Resonance: An Introduction to a Surface Spectroscopy Technique

    ERIC Educational Resources Information Center

    Tang, Yijun; Zeng, Xiangqun; Liang, Jennifer

    2010-01-01

    Surface plasmon resonance (SPR) has become an important optical biosensing technology in the areas of biochemistry, biology, and medical sciences because of its real-time, label-free, and noninvasive nature. The high cost of commercial devices and consumables has prevented SPR from being introduced in the undergraduate laboratory. Here, we present…

  11. Highly Stable Silver Nanoplates for Surface Plasmon Resonance Biosensing

    SciTech Connect

    Gao, Chuanbo; Lu, Zhenda; Chi, Miaofang; Liu, ying; Cheng, Quan; Yin, Yadong

    2012-01-01

    An SPR biosensor was developed by employing highly stable Au-protected Ag nanoplates (NP) as enhancers (see picture). Superior performance was achieved by depositing a thin and uniform coating of Au on the Ag surface while minimizing disruptive galvanic replacement and retaining the strong surface plasmon resonance (SPR) of the silver nanoplates.

  12. Resonances of nanoparticles with poor plasmonic metal tips

    PubMed Central

    Ringe, Emilie; DeSantis, Christopher J.; Collins, Sean M.; Duchamp, Martial; Dunin-Borkowski, Rafal E.; Skrabalak, Sara E.; Midgley, Paul A.

    2015-01-01

    The catalytic and optical properties of metal nanoparticles can be combined to create platforms for light-driven chemical energy storage and enhanced in-situ reaction monitoring. However, the heavily damped plasmon resonances of many catalytically active metals (e.g. Pt, Pd) prevent this dual functionality in pure nanostructures. The addition of catalytic metals at the surface of efficient plasmonic particles thus presents a unique opportunity if the resonances can be conserved after coating. Here, nanometer resolution electron-based techniques (electron energy loss, cathodoluminescence, and energy dispersive X-ray spectroscopy) are used to show that Au particles incorporating a catalytically active but heavily damped metal, Pd, sustain multiple size-dependent localized surface plasmon resonances (LSPRs) that are narrow and strongly localized at the Pd-rich tips. The resonances also couple with a dielectric substrate and other nanoparticles, establishing that the full range of plasmonic behavior is observed in these multifunctional nanostructures despite the presence of Pd. PMID:26617270

  13. The nonmonotonous shift of quantum plasmon resonance and plasmon-enhanced photocatalytic activity of gold nanoparticles.

    PubMed

    Ding, Si-Jing; Yang, Da-Jie; Li, Jin-Ling; Pan, Gui-Ming; Ma, Liang; Lin, Yong-Jie; Wang, Jia-Hong; Zhou, Li; Feng, Min; Xu, Hongxing; Gao, Shiwu; Wang, Qu-Quan

    2017-03-02

    The surface plasmon resonance (SPR) of metal nanoparticles exhibits quantum behaviors as the size decreases owing to the transitions of quantized conduction electrons, but most studies are limited to the monotonous SPR blue-shift caused by off-resonant transitions. Here, we demonstrate the nonmonotonous SPR red-shift caused by resonant electron transitions and photocatalytic activity enhanced by the quantum plasmon resonance of colloidal gold nanoparticles. A maximal SPR wavelength and the largest photocatalytic activity are observed in the quantum regime for the first time for the gold nanoparticles with a diameter of 3.6 nm. Theoretical analysis based on a quantum-corrected model reveals the evolution of SPR with quantized electron transitions and well explains the nonmonotonous size-dependencies of the SPR wavelength and absorption efficiency. These findings have profound implications for the understanding of the quantum nature of the SPR of metal nanoparticles and their applications in areas ranging from photophysics to photochemistry.

  14. Surface plasmon resonance biosensing toward real biological sample analysis

    NASA Astrophysics Data System (ADS)

    Cunche, Audrey; Bolduc, Olivier R.; Masson, Jean-Francois

    2009-05-01

    The development of monolayer chemistry based on amino acid and short peptides decreases significantly the nonspecific adsorption from biological samples such as serum. Nonspecific adsorption of proteins onto the surface of biosensors currently limits the applicability of many biosensing techniques in real biological samples. In order to minimize this problem, a methodology to immobilize short peptides on surface plasmon resonance (SPR) biosensors was developed using a short chain alkyl thiol monolayer derived with the selected peptides. The chain length of the alkane thiol linking the amino acid to the gold surface influences the physico-chemical properties of the layer and the amount of nonspecifically adsorbed proteins. Varying the composition of the monolayer with peptides formed from the natural amino acids investigates the physico-chemical properties required to minimize nonspecific adsorption of serum. It was observed from monolayers of single amino acids that the composition of the side chain of the amino acid greatly influences the resistance to nonspecific adsorption, with more polar, ionic and small chains resulting in an improved performance in biological samples. Building peptides of different lengths resulted in a further decrease of the amount of nonspecifically bound proteins from serum. Leaving the terminal carboxylic acid end of the peptide unreacted provides an anchoring point for a molecular receptor in the design of a biosensor. Biosensing will be demonstrated with a model system of β-lactamase.

  15. Plasmon resonant (e, 2e) spectroscopy on Be(0001)

    NASA Astrophysics Data System (ADS)

    Di Filippo, Gianluca; Sbaraglia, Damiano; Ruocco, Alessandro; Stefani, Giovanni

    2016-10-01

    We investigated the mechanisms of secondary electron (SE) emission from Be(0001) by impact of 100 and 150 eV electrons. We made use of (e, 2e) spectroscopy to disentangle the different SE production mechanisms. We observed a large increase in the SE yield when the energy loss of the primary electron equals the characteristic energy of volume and surface plasmons. The line shape of the SE spectrum associated with plasmon excitation reveals that one relevant emission mechanism corresponds to direct single-particle excitation in which the plasmon energy and momentum are transferred to a valence band electron of the solid. The contributions to the SE yield associated with surface and volume plasmon excitation are comparable in the case of specular geometry, where the projectile momentum is mainly transferred perpendicular to the surface. On the contrary, the emission of SEs associated with surface plasmon excitation is significantly enhanced when the exchanged momentum lies close to the surface plane and electrons are emitted from Be surface state. This reflects the increased sensitivity to surface modes of the latter geometry. Finally, the coupling between the direct ionization channel and the plasmon-assisted one results in a resonant increase of the secondary emission.

  16. Detecting Plasmon Resonance Energy Transfer with Differential Interference Contrast Microscopy

    SciTech Connect

    Augspurger, Ashley E.; Stender, Anthony S.; Han, Rui; Fang, Ning

    2013-12-30

    Gold nanoparticles are ideal probes for studying intracellular environments and energy transfer mechanisms due to their plasmonic properties. Plasmon resonance energy transfer (PRET) relies on a plasmonic nanoparticle to donate energy to a nearby resonant acceptor molecule, a process which can be observed due to the plasmonic quenching of the donor nanoparticle. In this study, a gold nanosphere was used as the plasmonic donor, while the metalloprotein cytochrome c was used as the acceptor molecule. Differential interference contrast (DIC) microscopy allows for simultaneous monitoring of complex environments and noble metal nanoparticles in real time. Using DIC and specially designed microfluidic channels, we were able to monitor PRET at the single gold particle level and observe the reversibility of PRET upon the introduction of phosphate-buffered saline to the channel. In an additional experiment, single gold particles were internalized by HeLa cells and were subsequently observed undergoing PRET as the cell hosts underwent morphological changes brought about by ethanol-induced apoptosis.

  17. THz Emission Based On Intersubband Plasmon Resonances

    SciTech Connect

    Coquelin, M.; Zobl, R.; Strasser, G.; Gornik, E.; Bakshi, P.; Umansky, V.; Heiblum, M.

    2010-01-04

    The radiative decay of collective plasma oscillations as a new mechanism for THz emission is studied. This phenomenon is based on the attractive interaction of two intersubband plasmons. This interaction can be viewed as a collective e-e scattering phenomenon. The emission results fit very well to the results of the current voltage measurements indicating that the conditions for a plasma instability are reached.

  18. Spectral dependence of fluorescence near plasmon resonant metal nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, Yeechi

    The optical properties of fluorophores are significantly modified when placed within the near field (0--100 nm) of plasmon resonant metal nanostructures, due to the competition between increased decay rates and "hotspots" of concentrated electric fields. The decay rates and effective electric field intensities are highly dependent on the relative position of dye and metal and the overlap between plasmon resonance and dye absorption and emission. Understanding these dependencies can greatly improve the performance of biosensing and nanophotonic devices. In this dissertation, the fluorescence intensity of organic dyes and CdSe quantum dots near single metal nanoparticles is studied as a function of the local surface plasmon resonance (LSPR) of the nanoparticle. Single metal nanoparticles have narrow, well-defined, intense local surface plasmon resonances that are tunable across the visible spectrum by changes in size and shape. First, we show that organic dyes can be self-assembled on single silver nanoprisms into known configurations by the hybridization of thiolated DNA oligomers. We correlate the fluorescence intensity of the dyes to the LSPR of the individual nanoprism to which they are attached. For each of three different organic dyes, we observe a strong correlation between the fluorescence intensity of the dye and the degree of spectral overlap with the plasmon resonance of the nanoparticle. On average, we observe the brightest fluorescence from dyes attached to metal nanoparticles that have a LSPR scattering peak 40--120 meV higher in energy than the emission peak of the fluorophore. Second, the plasmon-enhanced fluorescence from CdSe/CdS/CdZnS/ZnS core/shell quantum dots is studied near a variety of silver and gold nanoparticles. With single-particle scattering spectroscopy, the localized surface plasmon resonance spectra of single metal nanoparticles is correlated with the photoluminescence excitation (PLE) spectra of the nearby quantum dots. The PLE

  19. Enhanced nonlinear optics and other applications of resonant plasmonics

    NASA Astrophysics Data System (ADS)

    Robinson, Hans D.

    2011-10-01

    A surface plasmon polariton is the result of a photon coupling to a collective charge excitation in an electron gas. It is the optical equivalent of ordinary electrical currents at lower frequencies. By this analogy, just as regular electronic circuits can have resonances at discrete frequencies, metal nanostructures can exhibit plasmonic resonances in the optical frequency regime. These resonances tend to concentrate the electromagnetic field intensity by several orders of magnitude within nanometer scale hotspots located at sharp corners or inside narrow gaps in the structure. This phenomenon can be used to enhance a number of different effects, such as Raman scattering, fluorescence efficiency and photochemical reactions. This talk will give an overview of some of our recent work in this area, focusing on using plasmons to enhance the second harmonic generation (SHG) from nonlinear optical films. In particular, we have shown that the addition of plasmonic nanoparticles to such a film can increase the SHG emission as much as 2000 times. We have applied this idea to SHG generation in tapered optical fiber, where we obtain quasi-phase matching by patterning the deposition of metal nanoparticles onto the otherwise uniform nonlinear film that coats the fiber. I will also discuss our recent work on plasmonically enhanced nonlinear microscopy and plasmon enhanced photovotaics. [4pt] In collaboration with Kai Chen, Chih-Yu Jao, Chalongrat Daengngam, Jeong-Ah Lee, and J. Randall Heflin, VirginiaTech, Department of Physics; Sungsool Wi, VirginiaTech, Department of Chemistry; Lauren Neely, Vladimir Kochergin, MicroXact, Inc.; and Yong Xu, Virginia Tech, Department of Electrical and Computer Engineering.

  20. Microfluidic transmission surface plasmon resonance enhancement for biosensor applications

    NASA Astrophysics Data System (ADS)

    Lertvachirapaiboon, Chutiparn; Baba, Akira; Ekgasit, Sanong; Shinbo, Kazunari; Kato, Keizo; Kaneko, Futao

    2017-01-01

    The microfluidic transmission surface plasmon resonance (MTSPR) constructed by assembling a gold-coated grating substrate with a microchannel was employed for biosensor application. The transmission surface plasmon resonance spectrum obtained from the MTSPR sensor chip showed a strong and narrow surface plasmon resonance (SPR) peak located between 650 and 800 nm. The maximum SPR excitation was observed at an incident angle of 35°. The MTSPR sensor chip was employed for glucose sensor application. Gold-coated grating substrates were functionalized using 3-mercapto-1-propanesulfonic acid sodium salt and subsequently functionalized using a five-bilayer poly(allylamine hydrochloride)/poly(sodium 4-styrenesulfonate) to facilitate the coupling/decoupling of the surface plasmon and to prepare a uniform surface for sensing. The detection limit of our developed system for glucose was 2.31 mM. This practical platform represents a high possibility of further developing several biomolecules, multiplex systems, and a point-of-care assay for practical biosensor applications.

  1. Binding assays with artificial tethered membranes using surface plasmon resonance.

    PubMed

    Wiltschi, Birgit; Knoll, Wolfgang; Sinner, Eva-Kathrin

    2006-06-01

    Surface sensitive optical techniques based on surface plasmon resonance have become interesting for biosciences in the context of biorecognition and binding studies at functional surfaces. We use surface plasmon resonance spectroscopy (SPS) in combination with surface plasmon enhanced fluorescence spectroscopy (SPFS) for the characterization of interaction processes associated with biomembranes. The biological membrane is mimicked by a tethered membrane consisting of a planar lipid bilayer attached to a gold surface via a hydrophilic anchor peptide. The interaction between membrane-bound hydrophobic compounds and free hydrophilic molecules is monitored in real-time and with high sensitivity and selectivity by combined SPS/SPFS. In this review we shortly discuss the principles of surface plasmon resonance and its utilization in SPS and SPFS. A detailed description of the required instrumentation for combined SPS and SPFS is presented. Furthermore, we outline the design of a binding assay with a tethered bilayer and the procedure of the artificial membrane system built-up is delineated. We also present examples that demonstrate the potential of combined SPS/SPFS assays with artificial tethered membranes. The method provides insight into the interaction of integral membrane proteins with various hydrophilic ligands and the specific recognition of small lipophilic molecules by soluble proteins.

  2. INTERACTION OF LASER RADIATION WITH MATTER: Plasmon resonance in ellipsoidal nanoparticles with shells

    NASA Astrophysics Data System (ADS)

    Guzatov, D. V.; Oraevsky, A. A.; Oraevsky, Anatolii N.

    2003-09-01

    The phenomenon of plasmon resonance in ellipsoidal nanoparticles with shells is considered. Based on the geometrical sizes of a nanoparticle and its components, the theory is developed which allows the calculation of absorption spectra. Using the Maxwell — Garnett theory, a collective plasmon resonance is considered, which represents a nonlinear dependence of the plasmon frequency on the concentration of nanoparticles.

  3. Mid-infrared plasmonic resonances exploiting heavily-doped Ge on Si

    NASA Astrophysics Data System (ADS)

    Biagioni, P.; Sakat, E.; Baldassarre, L.; Calandrini, E.; Samarelli, A.; Gallacher, K.; Frigerio, J.; Isella, G.; Paul, D. J.; Ortolani, M.

    2015-03-01

    We address the behavior of mid-infrared localized plasmon resonances in elongated germanium antennas integrated on silicon substrates. Calculations based on Mie theory and on the experimentally retrieved dielectric constant allow us to study the tunability and the figures of merit of plasmon resonances in heavily-doped germanium and to preliminarily compare them with those of the most established plasmonic material, gold.

  4. Localized spoof surface plasmon resonances at terahertz range

    NASA Astrophysics Data System (ADS)

    Chen, Lin; Xu, Mengjian; Zang, Xiaofei; Peng, Yan; Zhu, Yiming

    2016-11-01

    The influence of the inner disk radius r, the filling ratio α, numbers of sectors N, and the gap g on transmission response for corrugated metallic disk (CMD) with single C-shaped resonator(CSR) has been fully studied. The results indicate that varying parameters r can efficiently excite the higher order spoof localized surface plasmon modes in corrugated metallic disk. The relationship between the bright dipole and dark multipolar resonances presents the possibility of high Q dark resonances excitation. All results may be of great interest for diverse applications.

  5. Surface plasmon resonance based fiber optic detection of chlorine utilizing polyvinylpyrolidone supported zinc oxide thin films.

    PubMed

    Tabassum, Rana; Gupta, Banshi D

    2015-03-21

    A highly sensitive chlorine sensor for an aqueous medium is fabricated using an optical fiber surface plasmon resonance (OFSPR) system. An OFSPR-based chlorine sensor is designed with a multilayer-type platform by zinc oxide (ZnO) and polyvinylpyrollidone (PVP) film morphology manipulations. Among all the methodologies of transduction reported in the field of solid state chemical and biochemical sensing, our attention is focused on the Kretschmann configuration optical fiber sensing technique using the mechanism of surface plasmon resonance. The optical fiber surface plasmon resonance (SPR) chlorine sensor is developed using a multimode optical fiber with the PVP-supported ZnO film deposited over a silver-coated unclad core of the fiber. A spectral interrogation mode of operation is used to characterize the sensor. In an Ag/ZnO/PVP multilayer system, the absorption of chlorine in the vicinity of the sensing region is performed by the PVP layer and the zinc oxide layer enhances the shift in resonance wavelength. It is, experimentally, demonstrated that the SPR wavelength shifts nonlinearly towards the red side of the visible region with an increase in the chlorine concentration in an aqueous medium while the sensitivity of the sensor decreases linearly with an increase in the chlorine concentration. As the proposed sensor utilizes an optical fiber, it possesses the additional advantages of fiber such as less signal degradation, less susceptibility to electromagnetic interference, possibility of remote sensing, probe miniaturization, probe re-usability, online monitoring, small size, light weight and low cost.

  6. Resonance coupling in plasmonic nanomatryoshka homo- and heterodimers

    NASA Astrophysics Data System (ADS)

    Ahmadivand, Arash; Sinha, Raju; Pala, Nezih

    2016-06-01

    Here, we examine the electromagnetic (EM) energy coupling and hybridization of plasmon resonances between closely spaced concentric nanoshells known as "nanomatryoshka" (NM) units in symmetric and antisymmetric compositions using the Finite Difference Time Domain (FDTD) analysis. Utilizing plasmon hybridization model, we calculated the energy level diagrams and verified that, in the symmetric dimer (in-phase mode in a homodimer), plasmonic bonding modes are dominant and tunable within the considered bandwidth. In contrast, in the antisymmetric dimer (out-of-phase mode in a heterodimer), due to the lack of the geometrical symmetry, new antibonding modes appear in the extinction profile, and this condition gives rise to repeal of dipolar field coupling. We also studied the extinction spectra and positions of the antibonding and bonding modes excited due to the energy coupling between silver and gold NM units in a heterodimer structure. Our analysis suggest abnormal shifts in the higher energy modes. We propose a method to analyze the behavior of multilayer concentric nanoshell particles in an antisymmetric orientation employing full dielectric function calculations and the Drude model based on interband transitions in metallic components. This study provides a method to predict the behavior of the higher energy plasmon resonant modes in entirely antisymmetric structures such as compositional heterodimers.

  7. Electrofocusing-enhanced localized surface plasmon resonance biosensors

    NASA Astrophysics Data System (ADS)

    Zhang, Jinling; Wang, Yi; Wong, Ten It; Liu, Xiaohu; Zhou, Xiaodong; Liedberg, Bo

    2015-10-01

    Localized surface plasmon resonance (LSPR) biosensors typically suffer from diffusion limited mass transport and nonspecific adsorption upon detection of biomolecules in real biofluids. We employ here a peptide-modified plasmonic gold nanohole (AuNH) array for real-time detection of human troponin I (cTnI). Applying a negative electric bias on the AuNH sensor chip enables us to attract and concentrate cTnI at the sensor surface, while repelling other proteins thus decreasing interferences due to nonspecific adsorption.Localized surface plasmon resonance (LSPR) biosensors typically suffer from diffusion limited mass transport and nonspecific adsorption upon detection of biomolecules in real biofluids. We employ here a peptide-modified plasmonic gold nanohole (AuNH) array for real-time detection of human troponin I (cTnI). Applying a negative electric bias on the AuNH sensor chip enables us to attract and concentrate cTnI at the sensor surface, while repelling other proteins thus decreasing interferences due to nonspecific adsorption. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03373j

  8. Optical Twist Induced by Plasmonic Resonance

    PubMed Central

    Chen, Jun; Wang, Neng; Cui, Liyong; Li, Xiao; Lin, Zhifang; Ng, Jack

    2016-01-01

    Harvesting light for optical torque is of significant importance, owing to its ability to rotate nano- or micro-objects. Nevertheless, applying a strong optical torque remains a challenging task: angular momentum must conserve but light is limited. A simple argument shows the tendency for two objects with strong mutual scattering or light exchange to exhibit a conspicuously enhanced optical torque without large extinction or absorption cross section. The torque on each object is almost equal but opposite, which we called optical twist. The effect is quite significant for plasmonic particle cluster, but can also be observed in structures with other morphologies. Such approach exhibits an unprecedentedly large torque to light extinction or absorption ratio, enabling limited light to exert a relatively large torque without severe heating. Our work contributes to the understanding of optical torque and introduces a novel way to manipulate the internal degrees of freedom of a structured particle cluster. PMID:27291860

  9. Plasmon resonance in warm dense matter.

    PubMed

    Thiele, R; Bornath, T; Fortmann, C; Höll, A; Redmer, R; Reinholz, H; Röpke, G; Wierling, A; Glenzer, S H; Gregori, G

    2008-08-01

    Collective Thomson scattering with extreme ultraviolet light or x rays is shown to allow for a robust measurement of the free electron density in dense plasmas. Collective excitations like plasmons appear as maxima in the scattering signal. Their frequency position can directly be related to the free electron density. The range of applicability of the standard Gross-Bohm dispersion relation and of an improved dispersion relation in comparison to calculations based on the dielectric function in random phase approximation is investigated. More important, this well-established treatment of Thomson scattering on free electrons is generalized in the Born-Mermin approximation by including collisions. We show that, in the transition region from collective to noncollective scattering, the consideration of collisions is important.

  10. Optical Twist Induced by Plasmonic Resonance

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Wang, Neng; Cui, Liyong; Li, Xiao; Lin, Zhifang; Ng, Jack

    2016-06-01

    Harvesting light for optical torque is of significant importance, owing to its ability to rotate nano- or micro-objects. Nevertheless, applying a strong optical torque remains a challenging task: angular momentum must conserve but light is limited. A simple argument shows the tendency for two objects with strong mutual scattering or light exchange to exhibit a conspicuously enhanced optical torque without large extinction or absorption cross section. The torque on each object is almost equal but opposite, which we called optical twist. The effect is quite significant for plasmonic particle cluster, but can also be observed in structures with other morphologies. Such approach exhibits an unprecedentedly large torque to light extinction or absorption ratio, enabling limited light to exert a relatively large torque without severe heating. Our work contributes to the understanding of optical torque and introduces a novel way to manipulate the internal degrees of freedom of a structured particle cluster.

  11. Plasmonic metamaterial absorber for broadband manipulation of mechanical resonances

    NASA Astrophysics Data System (ADS)

    Zhu, Hai; Yi, Fei; Cubukcu, Ertugrul

    2016-11-01

    Metamaterials are artificial materials that exhibit unusual properties for electromagnetic and sound waves. The quanta, namely photons and phonons, of these waves interact resonantly with these exotic man-made materials enabling many applications. For instance, resonant light absorption in photonic metamaterials can efficiently convert optical energy into heat based on the photothermal effect. Here, we present a plasmonic metamaterial that simultaneously supports thermomechanically coupled optical and mechanical resonances for controlling mechanical damping with light. In this metamaterial absorber with voltage-tunable Fano resonances, we experimentally achieve optically pumped coherent mechanical oscillations based on a plasmomechanical parametric gain mechanism over an ∼4 THz bandwidth. Through the reverse effect, optical damping of mechanical resonance is also achieved. Our results provide a metamaterial-based approach for optical manipulation of the dynamics of mechanical oscillators.

  12. Self-referenced spectroscopy using plasmon waveguide resonance biosensor

    PubMed Central

    Bahrami, Farshid; Maisonneuve, Mathieu; Meunier, Michel; Aitchison, J. Stewart; Mojahedi, Mo

    2014-01-01

    A plasmon waveguide resonance (PWR) sensor is designed, fabricated, and tested for self-referenced biosensing. The PWR sensor is able to support two different polarizations, TM and TE. The TM polarization has a large sensitivity to variations in the background refractive index while the TE polarization is more sensitive to the surface properties. The ability of the PWR sensor to simultaneously operate in both TM and TE modes is used to decouple the background index variations (bulk effects) from the changes in adlayer thickness (surface effects) via multimode spectroscopy. To benchmark the performance of the PWR, a conventional surface plasmon resonance (SPR) sensor is fabricated and tested under the same conditions. PMID:25136479

  13. Near-field hyperspectral quantum probing of multimodal plasmonic resonators

    NASA Astrophysics Data System (ADS)

    Cuche, A.; Berthel, M.; Kumar, U.; Colas des Francs, G.; Huant, S.; Dujardin, E.; Girard, C.; Drezet, A.

    2017-03-01

    Quantum systems, excited by an external source of photons, display a photodynamics that is ruled by a subtle balance between radiative or nonradiative energy channels when interacting with metallic nanostructures. We apply and generalize this concept to achieve a quantum probing of multimodal plasmonic resonators by collecting and filtering the broad emission spectra generated by a nanodiamond (ND) hosting a small set of nitrogen-vacancy (NV) color centers attached at the apex of an optical tip. Spatially and spectrally resolved information on the photonic local density of states (ph-LDOS) can be recorded with this technique in the immediate vicinity of plasmonic resonators, paving the way for a complete near-field optical characterization of any kind of nanoresonators in the single photon regime.

  14. Surface plasmon resonance imaging by holographic enhanced mapping.

    PubMed

    Mandracchia, B; Pagliarulo, V; Paturzo, M; Ferraro, P

    2015-04-21

    We designed, constructed and tested a holographic surface plasmon resonance (HoloSPR) objective-based microscope for simultaneous amplitude-contrast and phase-contrast surface plasmon resonance imaging (SPRi). SPRi is a widely spread tool for label-free detection of changes in refractive index and concentration, as well as mapping of thin films. Currently, most of the SPR sensors rely on the detection of amplitude or phase changes of light. Despite the high sensitivities achieved so far, each technique alone has a limited detection range with optimal sensitivity. Here we use a high numerical aperture objective that avoids all the limitations due to the use of a prism-based configuration, yielding highly magnified and distortion-free images. Holographic reconstructions of SPR images and real-time kinetic measurements are presented to show the capability of HoloSPR to provide a versatile imaging method for high-throughput SPR detection complementary to conventional SPR techniques.

  15. Sub-micron surface plasmon resonance sensor systems

    NASA Technical Reports Server (NTRS)

    Glazier, James A. (Inventor); Amarie, Dragos (Inventor)

    2013-01-01

    Wearable or implantable devices combining microfluidic control of sample and reagent flow and micro-cavity surface plasmon resonance sensors functionalized with surface treatments or coatings capable of specifically binding to target analytes, ligands, or molecules in a bodily fluid are provided. The devices can be used to determine the presence and concentration of target analytes in the bodily fluids and thereby help diagnose, monitor or detect changes in disease conditions.

  16. Resonant enhancement of Raman scattering in metamaterials with hybrid electromagnetic and plasmonic resonances

    NASA Astrophysics Data System (ADS)

    Guddala, Sriram; Narayana Rao, D.; Ramakrishna, S. Anantha

    2016-06-01

    A tri-layer metamaterial perfect absorber of light, consisting of (Al/ZnS/Al) films with the top aluminum layer patterned as an array of circular disk nanoantennas, is investigated for resonantly enhancing Raman scattering from C60 fullerene molecules deposited on the metamaterial. The metamaterial is designed to have resonant bands due to plasmonic and electromagnetic resonances at the Raman pump frequency (725 nm) as well as Stokes emission bands. The Raman scattering from C60 on the metamaterial with resonantly matched bands is measured to be enhanced by an order of magnitude more than C60 on metamaterials with off-resonant absorption bands peaking at 1090 nm. The Raman pump is significantly enhanced due to the resonance with a propagating surface plasmon band, while the highly impedance-matched electromagnetic resonance is expected to couple out the Raman emission efficiently. The nature and hybridization of the plasmonic and electromagnetic resonances to form compound resonances are investigated by numerical simulations.

  17. Evanescent field in surface plasmon resonance and surface plasmon field-enhanced fluorescence spectroscopies.

    PubMed

    Ekgasit, Sanong; Thammacharoen, Chuchaat; Yu, Fang; Knoll, Wolfgang

    2004-04-15

    The highly sensitive nature of surface plasmon resonance (SPR) spectroscopy and surface plasmon field-enhanced fluorescence spectroscopy (SPFS) are governed by the strong surface plasmon resonance-generated evanescent field at the metal/dielectric interface. The greatest evanescent field amplitude at the interface and the maximum attenuation of the reflectance are observed when a nonabsorbing dielectric is employed. An absorbing dielectric decreases the evanescent field enhancement at the interface. The SPR curve of an absorbing dielectric is characterized by a greater reflectance minimum and a broader curve, as compared to those of the nonabsorbing dielectric with the same refractive index. For a weakly absorbing dielectric, such as nanometer-thick surface-confined fluorophores, the absorption is too small to induce a significant change in the SPR curve. However, the presence of a minute amount of the fluorophore can be detected by the highly sensitive SPFS. The angle with the maximum fluorescence intensity of an SPFS curve is always smaller than the resonance angle of the corresponding SPR curve. This discrepancy is due to the differences of evanescent field distributions and their decay characteristics within the metal film and the dielectric medium. The fluorescence intensity in an SPFS curve can be expressed in terms of the evanescent field amplitude. Excellent correlations between the experimentally measured fluorescence intensities and the evanescent field amplitudes are observed.

  18. Plasmon resonance enhanced mechanical detection of ligand binding

    SciTech Connect

    Ariyaratne, Amila; Zocchi, Giovanni

    2015-01-05

    Small molecule binding to the active site of enzymes typically modifies the mechanical stiffness of the enzyme. We exploit this effect, in a setup which combines nano-mechanics and surface plasmon resonance (SPR) enhanced optics, for the label free detection of ligand binding to an enzyme. The large dynamic range of the signal allows to easily obtain binding curves for small ligands, in contrast to traditional SPR methods which rely on small changes in index of refraction. Enzyme mechanics, assessed by nano-rheology, thus emerges as an alternative to electronic and spin resonances, assessed by traditional spectroscopies, for detecting ligand binding.

  19. Gradient index plasmonic ring resonator with high extinction ratio

    NASA Astrophysics Data System (ADS)

    Zhou, Zidong; He, Pengbin; Xu, Jinyou; Zhuang, Xiujuan; Li, Yunyun; Pan, Anlian

    2014-02-01

    We propose and investigate a compact gradient index plasmonic ring resonator (Grin PRR) with strong light confinement and extinction ratio based on finite element method (FEM). Theoretical simulation reveals that the change of index gradient influences the resonant frequency, Q factor and the mode volume. Significantly, it is demonstrated that the extinction ratio of Grin PRR can be optimized by varying the index gradient for any radius. Index gradient can enhance extinction ratio at settled size, so this structure has both high extinction ratio and smaller size footprint. It could be very promising for the high-density optical integration.

  20. Sub-micron surface plasmon resonance sensor systems

    NASA Technical Reports Server (NTRS)

    Glazier, James A. (Inventor); Amarie, Dragos (Inventor)

    2011-01-01

    A sensor for detecting the presence of a target analyte, ligand or molecule in a test fluid, comprising a light transmissive substrate on which an array of surface plasmon resonant (SPR) elements is mounted is described. A multichannel sensor for detecting the presence of several targets with a single microchip sensor is described. A multichannel sensor including collections of SPR elements which are commonly functionalized to one of several targets is also described. The detectors sense changes in the resonant response of the SPR elements indicative of binding with the targets.

  1. Sub-micron surface plasmon resonance sensor systems

    NASA Technical Reports Server (NTRS)

    Glazier, James A. (Inventor); Dragnea, Bogdan (Inventor); Amarie, Dragos (Inventor)

    2010-01-01

    A sensor for detecting the presence of a target analyte, ligand or molecule in a test fluid, comprising a light transmissive substrate on which an array of surface plasmon resonant (SPR) elements is mounted is described. A multi-channel sensor for detecting the presence of several targets with a single microchip sensor is described. A multi-channel sensor including collections of SPR elements which are commonly functionalized to one of several targets is also described. The detectors sense changes in the resonant response of the SPR elements indicative of binding with the targets.

  2. Sub-micron surface plasmon resonance sensor systems

    NASA Technical Reports Server (NTRS)

    Glazier, James A. (Inventor); Amarie, Dragos (Inventor)

    2011-01-01

    A sensor for detecting the presence of a target analyte, ligand or molecule in a test fluid, comprising a light transmissive substrate on which an array of surface plasmon resonant (SPR) elements is mounted is described. A multi-channel sensor for detecting the presence of several targets with a single micro-chip sensor is described. A multi-channel sensor including collections of SPR elements which are commonly functionalized to one of several targets is also described. The detectors sense changes in the resonant response of the SPR elements indicative of binding with the targets.

  3. Sub-micron surface plasmon resonance sensor systems

    NASA Technical Reports Server (NTRS)

    Glazier, James A. (Inventor); Dragnea, Bogdan (Inventor); Amarie, Dragos (Inventor)

    2010-01-01

    A sensor for detecting the presence of a target analyte, ligand or molecule in a test fluid, comprising a light transmissive substrate on which an array of surface plasmon resonant (SPR) elements is mounted is described. A multi-channel sensor for detecting the presence of several targets with a single micro-chip sensor is described. A multi-channel sensor including collections of SPR elements which are commonly functionalized to one of several targets is also described. The detectors sense changes in the resonant response of the SPR elements indicative of binding with the targets.

  4. Sub-micron surface plasmon resonance sensor systems

    NASA Technical Reports Server (NTRS)

    Glazier, James A. (Inventor); Amarie, Dragos (Inventor)

    2012-01-01

    A sensor for detecting the presence of a target analyte, ligand or molecule in a test fluid, comprising a light transmissive substrate on which an array of surface plasmon resonant (SPR) elements is mounted is described. A multi-channel sensor for detecting the presence of several targets with a single microchip sensor is described. A multi-channel sensor including collections of SPR elements which are commonly functionalized to one of several targets is also described. The detectors sense changes in the resonant response of the SPR elements indicative of binding with the targets.

  5. Surface plasmon resonance-induced visible light photocatalytic reduction of graphene oxide: using Ag nanoparticles as a plasmonic photocatalyst.

    PubMed

    Wu, Tongshun; Liu, Sen; Luo, Yonglan; Lu, Wenbo; Wang, Lei; Sun, Xuping

    2011-05-01

    The present communication reports on the first preparation of reduced graphene oxide (rGO) via surface plasmon resonance (SPR)-induced visible light photocatalytic reduction of GO with the use of Ag nanoparticles (AgNPs) as a plasmonic photocatalyst in the presence of an electron donor (ED).

  6. High-resolution surface plasmon resonance sensor with Fano resonance in waveguide-coupled multilayer structures

    NASA Astrophysics Data System (ADS)

    Zheng, Gaige; Cong, Jiawei; Xu, Linhua; Wang, Jicheng

    2017-04-01

    An ultra-high resolution refractive-index sensor with the Kretschmann configuration was proposed and experimentally demonstrated. The Fano resonance (FR) in the attenuated total reflection curve arose from the interactions between the surface plasmon polariton and planar waveguide modes. It was shown to depend strongly on the structural parameters that governed the position of the FR and to be in good agreement with the results of electromagnetic calculations. The sensitivity by intensity was estimated to be 3.56 × 102-fold higher than that of conventional surface plasmon resonance sensors.

  7. Tunable triple Fano resonances based on multimode interference in coupled plasmonic resonator system.

    PubMed

    Li, Shilei; Zhang, Yunyun; Song, Xiaokang; Wang, Yilin; Yu, Li

    2016-07-11

    In this paper, an asymmetric plasmonic structure composed of two MIM (metal-insulator-metal) waveguides and two rectangular cavities is reported, which can support triple Fano resonances originating from three different mechanisms. And the multimode interference coupled mode theory (MICMT) including coupling phases is proposed based on single mode coupled mode theory (CMT), which is used for describing and explaining the multiple Fano resonance phenomenon in coupled plasmonic resonator systems. Just because the triple Fano resonances originate from three different mechanisms, each Fano resonance can be tuned independently or semi-independently by changing the parameters of the two rectangular cavities. Such, a narrow 'M' type of double Lorentzian-like line-shape transmission windows with the position and the full width at half maximum (FWHM) can be tuned freely is constructed by changing the parameters of the two cavities appropriately, which can find widely applications in sensors, nonlinear and slow-light devices.

  8. Narrow groove plasmonic nano-gratings for surface plasmon resonance sensing.

    PubMed

    Dhawan, Anuj; Canva, Michael; Vo-Dinh, Tuan

    2011-01-17

    We present a novel surface plasmon resonance (SPR) configuration based on narrow groove (sub-15 nm) plasmonic nano-gratings such that normally incident radiation can be coupled into surface plasmons without the use of prism-coupling based total internal reflection, as in the classical Kretschmann configuration. This eliminates the angular dependence requirements of SPR-based sensing and allows development of robust miniaturized SPR sensors. Simulations based on Rigorous Coupled Wave Analysis (RCWA) were carried out to numerically calculate the reflectance - from different gold and silver nano-grating structures - as a function of the localized refractive index of the media around the SPR nano-gratings as well as the incident radiation wavelength and angle of incidence. Our calculations indicate substantially higher differential reflectance signals, on localized change of refractive index in the narrow groove plasmonic gratings, as compared to those obtained from conventional SPR-based sensing systems. Furthermore, these calculations allow determination of the optimal nano-grating geometric parameters - i. e. nanoline periodicity, spacing between the nanolines, as well as the height of the nanolines in the nano-grating - for highest sensitivity to localized change of refractive index, as would occur due to binding of a biomolecule target to a functionalized nano-grating surface.

  9. Quantum plasmon resonances and coupling of small nanoparticles

    NASA Astrophysics Data System (ADS)

    Mario, Zapata-Herrera; Jefferson, Florez; Angela, Camacho

    2013-03-01

    In this work, we propose to extend a theoretical quantum approach to describe the behavior of the optical response as a function of both size and shape of small metal nanoparticles. By using classical models as well as quantum approaches we also want to study the nanoparticle's permittivity in the whole range of nanometers in order to define the different regimes at the nanoscale. In particular, we are interested in examining size and shape effects on the enhancement field factor and the absorption spectra for comparing with possible experiments. We study the role played by Localized Surface Plasmon Resonance in the coupling of small metal nanoparticles pairs by varying the distance between them by using an analogy between molecular electronic states and plasmonic excitations as a function of particle size and shape. We pay special atention on tunnelling and multipolar effects in order to predict the regime of dimer formation. The main interest in understanding the plasmon resonances of small nanoparticles lies in the applications in biology, catalysis and quantum optics.

  10. Nanostructured surfaces for surface plasmon resonance spectroscopy and imaging

    NASA Astrophysics Data System (ADS)

    Petefish, Joseph W.

    Surface plasmon resonance (SPR) has achieved widespread recognition as a sensitive, label-free, and versatile optical method for monitoring changes in refractive index at a metal-dielectric interface. Refractive index deviations of 10-6 RIU are resolvable using SPR, and the method can be used in real-time or ex-situ. Instruments based on carboxymethyl dextran coated SPR chips have achieved commercial success in biological detection, while SPR sensors can also be found in other fields as varied as food safety and gas sensing. Chapter 1 provides a physical background of SPR sensing. A brief history of the technology is presented, and publication data are included that demonstrate the large and growing interest in surface plasmons. Numerous applications of SPR sensors are listed to illustrate the broad appeal of the method. Surface plasmons (SPs) and surface plasmon polaritions (SPPs) are formally defined, and important parameters governing their spatial behavior are derived from Maxwell's equations and appropriate boundary conditions. Physical requirements for exciting SPs with incident light are discussed, and SPR imaging is used to illustrate the operating principle of SPR-based detection. Angle-tunable surface enhanced infrared absorption (SEIRA) of polymer vibrational modes via grating-coupled SPR is demonstrated in Chapter 2. Over 10-fold enhancement of C-H stretching modes was found relative to the absorbance of the same film in the absence of plasmon excitation. Modeling results are used to support and explain experimental observations. Improvements to the grating coupler SEIRA platform in Chapter 2 are explored in Chapters 3 and 4. Chapter 3 displays data for two sets of multipitch gratings: one set with broadly distributed resonances with the potential for multiband IR enhancement and the other with finely spaced, overlapping resonances to form a broadband IR enhancement device. Diffraction gratings having multiple periods were fabricated using a Lloyd

  11. Morphological studies of resonances in plasmonic metasurfaces for SPR sensing

    NASA Astrophysics Data System (ADS)

    Lelek, Jakub; Kwiecien, Pavel; Richter, Ivan; Homola, Jiří

    2015-05-01

    We investigate selected periodic arrays of nanostructures inspired by metasurfaces originally used in metamaterial structures and evaluate their potential for surface plasmon resonance applicable in sensing. Building blocks including rectangles, cut wires, crosses, fishnets, split ring resonators were ordered on suitable substrates and their reflection (R), transmission (T), and loss energy (L) spectra were calculated. The numerical studies were performed using our efficient in-house two-dimensional rigorous coupled-wave analysis technique. Our technique incorporates all the key improvements of the method available, taking into account both proper Fourier factorization rules, adaptive spatial resolution techniques, as well as structural symmetries. Using the R, T, and L spectra, we investigated spectral sensitivity of SPR and calculated the respective SPR sensor characteristics, such as figures of merit (FOM), enabling direct comparison of various structural morphologies for potential sensing applications. Also, optimization of the structures in terms of FOM has been performed to identify the most promising candidates. Additionally, to allow for interpretation of spectral resonant features and the interplay of individual and surface lattice resonances, we were gradually changing the morphology of individual building blocks from one type of element to another one. We believe that this study will bring insight into plasmonic behavior of nanostructured metasurfaces and will further benefit research into SPR biosensors.

  12. Plasmonic amplifiers: engineering giant light enhancements by tuning resonances in multiscale plasmonic nanostructures.

    PubMed

    Chen, Aiqing; Miller, Ryan L; DePrince, A Eugene; Joshi-Imre, Alexandra; Shevchenko, Elena; Ocola, Leonidas E; Gray, Stephen K; Welp, Ulrich; Vlasko-Vlasov, Vitalii K

    2013-06-10

    The unique ability of plasmonic nanostructures to guide, enhance, and manipulate subwavelength light offers multiple novel applications in chemical and biological sensing, imaging, and photonic microcircuitry. Here the reproducible, giant light amplification in multiscale plasmonic structures is demonstrated. These structures combine strongly coupled components of different dimensions and topologies that resonate at the same optical frequency. A light amplifier is constructed using a silver mirror carrying light-enhancing surface plasmons, dielectric gratings forming distributed Bragg cavities on top of the mirror, and gold nanoparticle arrays self-assembled into the grating grooves. By tuning the resonances of the individual components to the same frequency, multiple enhancement of the light intensity in the nanometer gaps between the particles is achieved. Using a monolayer of benzenethiol molecules on this structure, an average SERS enhancement factor ∼10⁸ is obtained, and the maximum enhancement in the interparticle hot-spots is ∼3 × 10¹⁰, in good agreement with FDTD calculations. The high enhancement factor, large density of well-ordered hot-spots, and good fidelity of the SERS signal make this design a promising platform for quantitative SERS sensing, optical detection, efficient solid state lighting, advanced photovoltaics, and other emerging photonic applications.

  13. Simultaneous surface plasmon resonance and x-ray absorption spectroscopy

    SciTech Connect

    Serrano, A.; Rodriguez de la Fuente, O.; Collado, V.; Rubio-Zuazo, J.; Castro, G. R.; Monton, C.; Garcia, M. A.

    2012-08-15

    We present an experimental setup for the simultaneous measurement of surface plasmon resonance (SPR) and x-ray absorption spectroscopy (XAS) on metallic thin films at a synchrotron beamline. The system allows measuring in situ and in real time the effect of x-ray irradiation on the SPR curves to explore the interaction of x-rays with matter. It is also possible to record XAS spectra while exciting SPR in order to study changes in the films induced by the excitation of surface plasmons. Combined experiments recording simultaneously SPR and XAS curves while scanning different parameters can be also carried out. The relative variations in the SPR and XAS spectra that can be detected with this setup range from 10{sup -3} to 10{sup -5}, depending on the particular experiment.

  14. Molecular resonant dissociation of surface-adsorbed molecules by plasmonic nanoscissors

    NASA Astrophysics Data System (ADS)

    Zhang, Zhenglong; Sheng, Shaoxiang; Zheng, Hairong; Xu, Hongxing; Sun, Mengtao

    2014-04-01

    The ability to break individual bonds or specific modes in chemical reactions is an ardently sought goal by chemists and physicists. While photochemistry based methodologies are very successful in controlling e.g. photocatalysis, photosynthesis and the degradation of plastic, it is hard to break individual molecular bonds for those molecules adsorbed on the surface because of the weak light-absorption in molecules and the redistribution of the resulting vibrational energy both inside the molecule and to its surrounding environment. Here we show how to overcome these obstacles with a plasmonic hot-electron mediated process and demonstrate a new method that allows the sensitive control of resonant dissociation of surface-adsorbed molecules by `plasmonic' scissors. To that end, we used a high-vacuum tip-enhanced Raman spectroscopy (HV-TERS) setup to dissociate resonantly excited NC2H6 fragments from Malachite green. The surface plasmons (SPs) excited at the sharp metal tip not only enhance the local electric field to harvest the light incident from the laser, but crucially supply `hot electrons' whose energy can be transferred to individual bonds. These processes are resonant Raman, which result in some active chemical bonds and then weaken these bonds, followed by dumping in lots of indiscriminant energy and breaking the weakest bond. The method allows for sensitive control of both the rate and probability of dissociation through their dependence on the density of hot electrons, which can be manipulated by tuning the laser intensity or tunneling current/bias voltage in the HV-TERS setup, respectively. The concepts of plasmonic scissors open up new versatile avenues for the deep understanding of in situ surface-catalyzed chemistry.The ability to break individual bonds or specific modes in chemical reactions is an ardently sought goal by chemists and physicists. While photochemistry based methodologies are very successful in controlling e.g. photocatalysis

  15. High harmonic generation by surface plasmon resonance: Design of plasmonic devices and their applications

    NASA Astrophysics Data System (ADS)

    Kim, Seung-Woo

    2010-03-01

    Seung-Woo Kim has been researching femtosecond ultrafast optics for ultraprecision manufacturing technologies including EUV and X-ray generation. Recently, he and his colleagues achieved a novel method of high-harmonic generation by exploiting the local field enhancement in the nanogap induced by resonant plasmons within a metallic nanostructure consisting of bow-tie shaped gold elements on a sapphire substrate. Plasmonic gold elements enhance the pulse intensity enough to induce high harmonic generation with no extra cavities at all. By injection of argon and xenon gas jets onto bow-tie nanostructures, high harmonics up to 21st (38 nm) order were produced while the incident laser intensity remained only 10^11 Wcm-2. Other nanostructures such as tapered cones are now being investigated to construct laptop-sized coherent EUV sources for advanced lithography and high resolution imaging applications.

  16. Vesicle fusion studied by surface plasmon resonance and surface plasmon fluorescence spectroscopy.

    PubMed

    Morigaki, Kenichi; Tawa, Keiko

    2006-08-15

    Substrate-supported planar lipid bilayers are generated most commonly by the adsorption and transformation of phospholipid vesicles (vesicle fusion). We have recently demonstrated that simultaneous measurements of surface plasmon resonance (SPR) and surface plasmon fluorescence spectroscopy (SPFS) are highly informative for monitoring lipid membranes on solid substrates. SPR and SPFS provide information on the amount and topography of adsorbed lipid membranes, respectively. In this study, the vesicle fusion process was studied in detail by measuring SPR-SPFS at a higher rate and plotting the obtained fluorescence intensity versus film thickness. We could track the initial adsorption of vesicles, the onset of vesicle rupture occurring at certain vesicle coverage of the surface, and the autocatalytic transformation into planar bilayers. We also monitored vesicle fusion of the same vesicle suspensions by quartz crystal microbalance with dissipation monitoring (QCM-D). We compared the results obtained from SPR-SPFS and QCM-D to highlight the unique information provided by SPR-SPFS.

  17. Microscale Heat Transfer Transduced by Surface Plasmon Resonant Gold Nanoparticles

    PubMed Central

    Roper, D. Keith; Ahn, W.; Hoepfner, M.

    2008-01-01

    Visible radiation at resonant frequencies is transduced to thermal energy by surface plasmons on gold nanoparticles. Temperature in ≤10-microliter aqueous suspensions of 20-nanometer gold particles irradiated by a continuous wave Ar+ ion laser at 514 nm increased to a maximum equilibrium value. This value increased in proportion to incident laser power and in proportion to nanoparticle content at low concentration. Heat input to the system by nanoparticle transduction of resonant irradiation equaled heat flux outward by conduction and radiation at thermal equilibrium. The efficiency of transducing incident resonant light to heat by microvolume suspensions of gold nanoparticles was determined by applying an energy balance to obtain a microscale heat-transfer time constant from the transient temperature profile. Measured values of transduction efficiency were increased from 3.4% to 9.9% by modulating the incident continuous wave irradiation. PMID:19011696

  18. Fano resonances in a plasmonic waveguide system composed of stub coupled with a square cavity resonator

    NASA Astrophysics Data System (ADS)

    Binfeng, Yun; Hu, Guohua; Zhang, Ruohu; Yiping, Cui

    2016-05-01

    A coupled plasmonic waveguide resonator system which can produce sharp and asymmetric Fano resonances was proposed and analyzed. Two Fano resonances are induced by the interactions between the narrow discrete whispering gallery modes in a plasmonic square cavity resonator and the broad spectrum of the metal-insulator-metal stub resonator. The relative peak amplitudes between the 1st and 2nd order Fano resonances can be adjusted by changing the structure parameters, such as the square cavity size, the stub size and the center-to-center distance between the square cavity and the stub resonators. And the 1st order Fano resonant peak, which is a standing-wave mode, will split into two resonant peaks (one standing-wave mode and one traveling-wave mode) when it couples with the 2nd Fano resonance. Also, the potential of the proposed Fano system as an integrated slow-light device and refractive index sensor was investigated. The results show that a maximum group index of about 100 can be realized, and a linear refractive index sensitivity of 938 nm/RIU with a figure of merit of about 1.35 × 104 can be obtained.

  19. Universal scaling and Fano resonance in the plasmon coupling between gold nanorods.

    PubMed

    Woo, Kat Choi; Shao, Lei; Chen, Huanjun; Liang, Yao; Wang, Jianfang; Lin, Hai-Qing

    2011-07-26

    The plasmon coupling between metal nanocrystals can lead to large plasmon shifts, enormous electric field enhancements, and new plasmon modes. Metal nanorods, unlike spherical ones, possess a transverse and a longitudinal plasmon mode owing to their geometrical anisotropy. Consequently, the plasmon coupling between metal nanorods is much more complicated than that between nanospheres. For the latter, experimental approaches, simple scaling relationships, and exact analytic solutions have been developed for describing the plasmon coupling. In this study, we have carried out extensive finite-difference time-domain simulations to understand the plasmon coupling in the dimers of Au nanorods that are aligned along their length axes. The effects of the gap distance, longitudinal plasmon energy, and end shape of the nanorod monomers on the plasmon coupling have been scrutinized. The coupling energy diagrams show a general anticrossing behavior. All of them can be rescaled into one simple and universal hyperbolic formula. A theoretical model based on two interacting mechanical oscillators has been developed to understand the plasmon coupling between two arbitrarily varying Au nanorods. This model, together with the universal equation, allows for the determination of the coupled plasmon energies of Au nanorod dimers with high accuracies. Furthermore, the Fano interference has been observed in the nanorod heterodimers, with its behavior being dependent on the gap distance and plasmon energies of the nanorod monomers. Our results will be useful for predicting the coupled plasmon energies of metal nanorod dimers in a variety of plasmonic applications and understanding the Fano resonance in plasmonic nanostructures.

  20. Broadband Plasmon Waveguide Resonance Spectroscopy for Probing Biological Thin Films

    PubMed Central

    ZHANG, HAN; OROSZ, KRISTINA S.; TAKAHASHI, HIROMI; SAAVEDRA, S. SCOTT

    2010-01-01

    A commercially available spectrometer has been modified to perform plasmon waveguide resonance (PWR) spectroscopy over a broad spectral bandwidth. When compared to surface plasmon resonance (SPR), PWR has the advantage of allowing measurements in both s- and p-polarizations on a waveguide surface that is silica or glass rather than a noble metal. Here the waveguide is a BK7 glass slide coated with silver and silica layers. The resonance wavelength is sensitive to the optical thickness of the medium adjacent to the silica layer. The sensitivity of this technique is characterized and compared with broadband SPR both experimentally and theoretically. The sensitivity of spectral PWR is comparable to that of spectral SPR for samples with refractive indices close to that of water. The hydrophilic surface of the waveguide allows supported lipid bilayers to be formed spontaneously by vesicle fusion; in contrast, the surface of an SPR chip requires chemical modification to create a supported lipid membrane. Broadband PWR spectroscopy should be a useful technique to study biointerfaces, including ligand binding to transmembrane receptors and adsorption of peripheral proteins on ligand-bearing membranes. PMID:19796490

  1. Graphene plasmonics: multiple sharp Fano resonances in silver split concentric nanoring/disk resonator dimers on a metasurface

    NASA Astrophysics Data System (ADS)

    Ahmadivand, Arash; Sinha, Raju; Pala, Nezih

    2015-08-01

    We introduce a platform based on plasmonic metamaterials to design various optical devices. A simple structure brokenring with a nanodisk at the center is utilized to excite and hybridize the plasmon resonant modes. We show that the proposed nanoantenna is able to support strong sub- and superradiant plasmon resonances because of its unique geometrical features. Using the concentric ring/disk in a dimer orientation as a nanoantenna on a multilayer metasurface consisting of graphene monolayer, we induced double sharp plasmonic Fano resonant modes in the transmission window across the visible to the near-infrared region. Considering the strong polarization-dependency of the broken-ring/disk dimer antenna, it is shown that the proposed plasmonic metamaterial can be tailored as an optical router device for fast switching applications. This understanding opens new paths to employ plasmonic metamaterials with simple geometrical nanoscale blocks for sensing and switching applications.

  2. CO2 -Assisted Fabrication of Two-Dimensional Amorphous Molybdenum Oxide Nanosheets for Enhanced Plasmon Resonances.

    PubMed

    Liu, Wei; Xu, Qun; Cui, Weili; Zhu, Chuanhui; Qi, Yuhang

    2017-02-01

    As a remarkable class of plasmonic materials, two dimensional (2D) semiconductor compounds have attracted attention owing to their controlled manipulation of plasmon resonances in the visible light spectrum, which outperforms conventional noble metals. However, tuning of plasmonic resonances for 2D semiconductors remains challenging. Herein, we design a novel method to obtain amorphous molybdenum oxide (MoO3 ) nanosheets, in which it combines the oxidation of MoS2 and subsequent supercritical CO2 -treatment, which is a crucial step for the achievement of amorphous structure of MoO3 . Upon illumination, hydrogen-doped MoO3 exhibits tuned surface plasmon resonances in the visible and near-IR regions. Moreover, a unique behavior of the amorphous MoO3 nanosheets has been found in an optical biosensing system; there is an optimum plasmon resonance after incubation with different BSA concentrations, suggesting a tunable plasmonic device in the near future.

  3. A wide linear range surface plasmon resonance biosensor

    NASA Astrophysics Data System (ADS)

    Sun, Zhanliang; He, Yonghong; Shao, Yonghong; Guo, Jihua

    2006-09-01

    A new surface plasmon resonance (SPR) sensor based on polarization interferometry and angle modulation is presented. Its feature is that it can provide the same sensitivity in a wide refractive index (RI) range. Moreover, the sensitivity ofthis SPR sensor is insensitive to the thickness of gold films over about 5 mu. Experimental results show that its resolution in an integration time of 0.5 second is 1.7 × 10 -7 refractive index units (RIU). It demonstrates great potential to be commercialized and widely applied in biological research.

  4. Plasmonic resonance of bowtie antennas and their geometry dependence

    NASA Astrophysics Data System (ADS)

    Dong, Ruilin; Nie, Yixuan; Yao, Shang; Jiang, Yucheng; Meng, Jing; Yang, Yuping

    2012-12-01

    In order to provide a guide for the design and optimization of bowtie-shaped antenna arrays, their plasmonic properties have been experimentally and numerically investigated with emphasis on geometry and gap separation in THz frequencies. A stronger absorption, frequent red-shift and a higher Q-factor were observed in bowtie dimers, instead of the monomers. Based on the finite-element (FE) simulations using CST Microwave Studio, it was found that these resonant properties of the periodic bowtie particles can be further modulated by their geometric factors, including aspect ratio, area porosity as well as gap separation.

  5. Fabrication of doubly resonant plasmonic nanopatch arrays on graphene

    NASA Astrophysics Data System (ADS)

    Grande, M.; Stomeo, T.; Bianco, G. V.; Vincenti, M. A.; de Ceglia, D.; Petruzzelli, V.; Bruno, G.; De Vittorio, M.; Scalora, M.; D'Orazio, A.

    2013-06-01

    We report theoretical and experimental investigations of the optical response of two-dimensional periodic arrays of rectangular gold nanopatches grown on a monolayer graphene placed on a glass substrate. We discuss the numerical analysis and optical characterization by means of reflection spectra and show that rectangular nanopatches display a polarization-dependent response, at normal incidence, which leads to double plasmonic resonances due to the Wood anomaly. We detail the fabrication process highlighting how the resist primer and the adhesion layer can reduce and impede the graphene doping due to the environment and to the nanopatches, respectively, by means of Raman spectroscopy.

  6. Surface plasmon resonance imaging for parallelized detection of protein biomarkers

    NASA Astrophysics Data System (ADS)

    Piliarik, Marek; Párová, Lucie; Vaisocherová, Hana; Homola, Jiří

    2009-05-01

    We report a novel high-throughput surface plasmon resonance (SPR) biosensor for rapid and parallelized detection of protein biomarkers. The biosensor is based on a high-performance SPR imaging sensor with polarization contrast and internal referencing which yields a considerably higher sensitivity and resolution than conventional SPR imaging systems (refractive index resolution 2 × 10-7 RIU). We combined the SPR imaging biosensor with microspotting to create an array of antibodies. DNA-directed protein immobilization was utilized for the spatially resolved attachment of antibodies. Using Human Chorionic Gonadotropin (hCG) as model protein biomarker, we demonstrated the potential for simultaneous detection of proteins in up to 100 channels.

  7. Studies on surface plasmon resonance and photoluminescence of silver nanoparticles.

    PubMed

    Smitha, S L; Nissamudeen, K M; Philip, Daizy; Gopchandran, K G

    2008-11-01

    Silver nanoparticles of different sizes were prepared by citrate reduction and characterized by UV-vis absorbance spectra, TEM images and photoluminescence spectra. The morphology of the colloids obtained consists of a mixture of nanorods and spheres. The surface plasmon resonance (SPR) and photoemission properties of Ag nanoparticles are found to be sensitive to citrate concentration. A blue shift in SPR and an enhancement in photoluminescence intensity are observed with increase in citrate concentration. Effect of addition of KCl and variation of pH in photoluminescence was also studied.

  8. Examination of bacteria drug resistance utilizing surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Chiang, Ya-Ling; Chen, How-Foo; Lin, Chi-Hung; Chen, Shean-Jen

    2007-05-01

    An antimicrobial testing method using surface plasmon resonance to improve the present techniques is reported in this paper. Different from conventional methods, namely Kirby-Bauer disk diffusion and variations of broth microdilution, the examination time is reduced from 18-24 hours or more to less than one hour after the treatment of antibiotics. E-coli resistant and susceptible to ampicillin are used in the test to demonstrate this innovative method. It is generally known that discovering a method to exam the bacterium resistance rapidly and correctly is very important for patients and for preventing infective disease from spreading. The method reported can benefit this requirement.

  9. Transparency windows of the plasmonic nanostructure composed of C-shaped and U-shaped resonators

    NASA Astrophysics Data System (ADS)

    Zhou, Xin; Ouyang, Min; Tang, Bin; Wang, Zhibing; He, Jun

    2017-02-01

    We in this study investigated numerically the plasmon-induced transparency (PIT) effect on the plasmonic nanostructures composed of C-shaped and U-shaped resonators by using finite difference time domain (FDTD) method. The PIT effect in the nanosystem stemmed from the near field coupling between the bright and dark modes. The nanostructure composed of three resonators exhibited double PIT effect. And the PIT spectral response of the proposed nanostructures was demonstrated having a dependence on the parameters of the compound plasmonic system such as the widths of C-shaped resonator and U-shaped resonator, the resonators spatial arrangement and the edge-to-edge distance between the adjacent resonators. The electric and magnetic field distributions of certain resonance wavelengths were also given to discuss the underlying physics. The resonator design strategy opens up a rich pathway to develop the building block of systems for all optical switching, plasmonic sensing applications.

  10. Metal nanodisk hybrid plasmonic resonator on dielectric substrate for relieved fabrication complexity.

    PubMed

    Jeong, Chang Yeong; Kim, Myunghwan; Kim, Sangin

    2014-03-10

    We propose a metal nanodisk hybrid plasmonic resonator (HPR), which consists of a metallic nanodisk on top of a dielectric slab. In contrast to the previously studied plasmonic resonator structures based on metal substrates such as the nanopatch resonator, the fabrication process of the proposed resonator is much easier because of a dielectric substrate. The performance of the proposed resonator has been theoretically investigated and compared to the previously studied structures. It has been shown that the performance of the proposed resonator is superior to that of the nanopatch resonator and comparable to that of a hybrid resonator based on a metal substrate.

  11. Tunable Dipole Surface Plasmon Resonances of Silver Nanoparticles by Cladding Dielectric Layers

    PubMed Central

    Liu, Xiaotong; Li, Dabing; Sun, Xiaojuan; Li, Zhiming; Song, Hang; Jiang, Hong; Chen, Yiren

    2015-01-01

    The tunability of surface plasmon resonance can enable the highest degree of localised surface plasmon enhancement to be achieved, based on the emitting or absorbing wavelength. In this article, tunable dipole surface plasmon resonances of Ag nanoparticles (NPs) are realized by modification of the SiO2 dielectric layer thicknesses. SiO2 layers both beneath and over the Ag NPs affected the resonance wavelengths of local surface plasmons (LSPs). By adjusting the SiO2 thickness beneath the Ag NPs from 5 nm to 20 nm, the dipole surface plasmon resonances shifted from 470 nm to 410 nm. Meanwhile, after sandwiching the Ag NPs by growing SiO2 before NPs fabrication and then overcoating the NPs with various SiO2 thicknesses from 5 nm to 20 nm, the dipole surface plasmon resonances changed from 450 nm to 490 nm. The SiO2 cladding dielectric layer can tune the Ag NP surface charge, leading to a change in the effective permittivity of the surrounding medium, and thus to a blueshift or redshift of the resonance wavelength. Also, the quadrupole plasmon resonances were suppressed by the SiO2 cladding layer because the dielectric SiO2 can suppress level splitting of surface plasmon resonances caused by the Ag NP coupling effect. PMID:26218501

  12. Plasmonic phase transition and phase retardation: essential optical characteristics of localized surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Chen, Wen-Yu; Lin, Chun-Hung; Chen, Wei-Ting

    2013-09-01

    Phase transition that occurs around the spectral position of localized surface plasmon resonance (LSPR) has various applications for light manipulation and refractive index sensing. Previous studies focused on phase responses of specific plasmonic structures, whereas the general theoretical analysis remains inadequate. In this study, we analytically modeled the phase spectra and the intensity spectra of silver nanodots with temporal coupled-mode theory. The phase transition occurs at the transmission dip, whereas the phase of reflection varies much more gradually. We further derived the equation for the slope of the phase at the transmission dip, which is a function of the rates of Ohmic dissipation and emission. The theoretical analysis is also applicable for wide varieties of LSPR systems and provides an intuitive physical mechanism for phase properties. Then, based on the fundamental discussion, we further investigated plasmonic phase retardation in anisotropic nanodots for the application of boosting the figure of merit (FOM) of refractive index sensing. The anisotropic nanodots induce plasmonic phase transitions, which spectrally split, for transmission waves polarized along the symmetric axes. Thus, anisotropy induces relative phase retardation in the narrow spectral region between the wavelengths of the LSPRs. We numerically manipulated the full width at half maximum of the ellipsometric spectra by adjusting the aspect ratio of the nanodots and observed an FOM of 24.3. In addition, experiments were performed to demonstrate the feasibility of this arrangement.Phase transition that occurs around the spectral position of localized surface plasmon resonance (LSPR) has various applications for light manipulation and refractive index sensing. Previous studies focused on phase responses of specific plasmonic structures, whereas the general theoretical analysis remains inadequate. In this study, we analytically modeled the phase spectra and the intensity spectra of

  13. Electronic modulation of infrared radiation in graphene plasmonic resonators.

    PubMed

    Brar, Victor W; Sherrott, Michelle C; Jang, Min Seok; Kim, Seyoon; Kim, Laura; Choi, Mansoo; Sweatlock, Luke A; Atwater, Harry A

    2015-05-07

    All matter at finite temperatures emits electromagnetic radiation due to the thermally induced motion of particles and quasiparticles. Dynamic control of this radiation could enable the design of novel infrared sources; however, the spectral characteristics of the radiated power are dictated by the electromagnetic energy density and emissivity, which are ordinarily fixed properties of the material and temperature. Here we experimentally demonstrate tunable electronic control of blackbody emission from graphene plasmonic resonators on a silicon nitride substrate. It is shown that the graphene resonators produce antenna-coupled blackbody radiation, which manifests as narrow spectral emission peaks in the mid-infrared. By continuously varying the nanoresonator carrier density, the frequency and intensity of these spectral features can be modulated via an electrostatic gate. This work opens the door for future devices that may control blackbody radiation at timescales beyond the limits of conventional thermo-optic modulation.

  14. Multiplex fiber-optic biosensor using multiple particle plasmon resonances

    NASA Astrophysics Data System (ADS)

    Lin, Hsing-Ying; Huang, Chen-Han; Liu, Yu-Chia; Huang, Kuo-Wei; Chau, Lai-Kwan

    2012-02-01

    Multiplex fiber-optic biosensor implemented by integrating multiple particle plasmon resonances (PPRs), molecular bioassays, and microfluidics is successfully demonstrated. The multiple PPRs are achieved by chemical immobilization of silver nanoparticles (AgNPs) and gold nanorods (AuNRs) separately on two unclad portions of an optical fiber. The difference in morphology and nature of material of AgNPs and AuNRs are exploited to yield multiple plasmonic absorptions at 405 and 780 nm in the absorption spectrum measured from optical fiber by white light source illumination. Through the coaxial excitation of light-emitting diodes (LEDs) with 405 and 800 nm wavelengths, the distinct PPRs are advantageous for real-time and simultaneous detection of multiple analyte-probe pairs as AgNPs and AuNRs are separately functionalized with specific bio-probes. Here, the multi-window fiber-optic particle plasmon resonance (FO-PPR) biosensor has been shown to be capable of simultaneously detecting anti-dinitrophenyl antibody (anti-DNP, MW = 220 kDa) via N-(2,4-dinitrophenyl)-6-aminohexanoic acid (DNP, MW = 297.27 Da) functionalized AgNPs and streptavidin (MW = 75 kDa) via N-(3-aminopropyl)biotinamide trifluoroacetate (biotin, MW = 414.44 Da) functionalized AuNRs. The multiplex sensing chip possesses several advantages, including rapid and parallel detection of multiple analytes on a single chip, minimized sample to sample variation, reduced amount of sensor chip, and reduced analyte volume, hence it is ideally suitable for high-throughput multiplex biochemical sensing applications.

  15. Surface plasmon resonance phenomenon of the insulating state polyaniline

    SciTech Connect

    Umiati, Ngurah Ayu Ketut; Triyana, Kuwat; Kamsul

    2015-04-16

    Surface Plasmon Resonance (SPR) phenomenon of the insulating polyaniline (PANI) is has been observed. Surface Plasmon (SP) is the traveled electromagnetic wave that passes through the interface of dielectric metal and excited by attenuated total reflection (ATR) method in Kretschmannn configuration (Au-PANI prism). The resonance condition is observed through the angle of SPR in such condition that SP wave is coupled by the evanescent constant of laser beam. In this research, the laser beam was generated by He–Ne and its wavelength (λ) was 632,8 nm. SPR curve is obtained through observation of incidence angles of the laser beam in prism. SPR phenomenon at the boundary between Au – PANI layer has showed by reflection dip when the laser beam passes through the prism. In this early study, the observation was carried out through simulation Winspall 3.02 software and preliminary compared with some experimental data reported in other referred literatures. The results shows that the optimum layer of Au and polyaniline are 50 and 1,5 nm thick respectively. Our own near future experimental work would be further performed and reported elsewhere.

  16. Compact silicon hybrid plasmonic microring resonator-based polarization demultiplexer

    NASA Astrophysics Data System (ADS)

    Xu, Yin; Xiao, Jinbiao

    2015-08-01

    A compact silicon-based polarization demultiplexer (P-DEMUX) composed of a microring resonator in hybrid plasmonic waveguides and two bus channels in silicon wires is proposed and characterized. The modal analysis shows that the behaviors of TE modes for the hybrid plasmonic microring and silicon wire are similar, while those of TM modes illustrate significant difference, leading to strong polarization-dependence. As a result, the input TE mode can output from the drop port at the resonant wavelength while the input TM mode directly outputs from the through port with nearly neglected coupling. The present P-DEMUX can be easily applied to construct on-chip wavelength/polarization division multiplexing, further increasing the capacity of the interconnect system. Results show that a compact P-DEMUX is achieved, where the radius of the microring in the center is only 2.042 µm, and the extinction ratio and insertion loss are, respectively, ∼18.04 (19.89) and ∼0.61 (0.42) dB for TE (TM) mode, at the wavelength of 1550 nm. In addition, fabrication tolerances to the structural parameters are analyzed in detail and the evolution of the input field through the proposed P-DEMUX is also presented.

  17. Scattering-Type Surface-Plasmon-Resonance Biosensors

    NASA Technical Reports Server (NTRS)

    Wang, Yu; Pain, Bedabrata; Cunningham, Thomas; Seshadri, Suresh

    2005-01-01

    Biosensors of a proposed type would exploit scattering of light by surface plasmon resonance (SPR). Related prior biosensors exploit absorption of light by SPR. Relative to the prior SPR biosensors, the proposed SPR biosensors would offer greater sensitivity in some cases, enough sensitivity to detect bioparticles having dimensions as small as nanometers. A surface plasmon wave can be described as a light-induced collective oscillation in electron density at the interface between a metal and a dielectric. At SPR, most incident photons are either absorbed or scattered at the metal/dielectric interface and, consequently, reflected light is greatly attenuated. The resonance wavelength and angle of incidence depend upon the permittivities of the metal and dielectric. An SPR sensor of the type most widely used heretofore includes a gold film coated with a ligand a substance that binds analyte molecules. The gold film is thin enough to support evanescent-wave coupling through its thickness. The change in the effective index of refraction at the surface, and thus the change in the SPR response, increases with the number of bound analyte molecules. The device is illuminated at a fixed wavelength, and the intensity of light reflected from the gold surface opposite the ligand-coated surface is measured as a function of the angle of incidence. From these measurements, the angle of minimum reflection intensity is determined

  18. Synthesis and tuning of gold nanorods with surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Shajari, Daryush; Bahari, Ali; Gill, Pooria; Mohseni, Mojtaba

    2017-02-01

    Gold nanostructures in general and gold nanorods in particular due to their plasmon resonance has been employed for many applications, such as biosensors. For the biosensors uses, gold nanorods remain popular and reproducibility of them is the most important and critical. In the present work we used six different CTAB (Hexadecyltrimethylammonium bromide) products and one BDAC (Benzyldimethylhexadecylammonium chloride) with varying silver nitrate concentration in the seed-mediated growth of gold nanostructures. We synthesized gold nanorods with varying aspect ratio up to 5.5 with a longitudinal surface plasmon resonance peak from 670 to 950 nm. We obtained excellent rod-shape gold nanostructures witch were reliable and reproducible with our method based on common seed-mediated growth. The synthesized nanostructures were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD). Here, we report our method in more detail as a user-friendly guide for the production of gold nanorods and tuning of their aspect ratios.

  19. Superradiant amplification of terahertz radiation by plasmons in inverted graphene with a planar distributed Bragg resonator

    SciTech Connect

    Polischuk, O. V. Popov, V. V.; Otsuji, T.

    2015-11-15

    It is shown theoretically that stimulated generation of terahertz radiation by plasmons in graphene with a planar distributed Bragg resonator is possible at two different frequencies for each plasmon mode. This behavior may be attributed to the superradiance of the collective plasmon mode, which is associated with superlinear increase in the radiative damping of the plasmons with increase in pumping power. As a result, the curves of the radiative damping and the plasmon gain as a function of the pumping power intersect at two points corresponding to different generation conditions.

  20. Promoted sulfurization of a single silver nanoparticle by plasmon resonance under white light illumination

    NASA Astrophysics Data System (ADS)

    Ikeda, Yuki; Miyata, Masashi; Takahara, Junichi

    2017-04-01

    We demonstrate the rapid spectral shift of the plasmon resonant peak from a single silver nanoparticle deposited on a dielectric-coated silver film in air under white light illumination. This shift occurs within several hours of white light illumination under the resonant condition of the metal–insulator–metal structure formed below the particle and is attributed to promoted sulfurization at the surface of the single silver nanoparticle resulting from the plasmonic heat generation. This thermal plasmonic effect will play a crucial role in the stability of plasmonic devices in the future.

  1. Quadrupole lattice resonances in plasmonic crystal excited by cylindrical vector beams

    PubMed Central

    Sakai, Kyosuke; Nomura, Kensuke; Yamamoto, Takeaki; Omura, Tatsuya; Sasaki, Keiji

    2016-01-01

    We report a scheme to exploit low radiative loss plasmonic resonance by combining a dark (subradiant) mode and a lattice resonance. We theoretically demonstrate that such dark-mode lattice resonances in periodic arrays of nanodisks or plasmonic crystals can be excited by vertically incident light beams. We investigate the excitation of lattice resonances in a finite sized, square-lattice plasmonic crystal by two types of cylindrical vector beams and a linearly polarized Gaussian beam. Quadrupole lattice resonances are excited by all three beams, and the largest peak intensity is obtained by using a specific type of cylindrical vector beam. Because of their lower radiative losses with many hotspots, the quadrupole lattice resonances in plasmonic crystal may pave the way for photonic research and applications that require strong light-matter interactions. PMID:27734923

  2. Tunable plasmon resonance in the nanobars and split ring resonator(SRR) composite structure

    NASA Astrophysics Data System (ADS)

    Xu, Haiqing; Li, Hongjian; Xiao, Gang; Chen, Qiao

    2016-10-01

    We have proposed a multi-band metamaterials composed of bars and planer SRR. There are three sharp peaks in the transmission spectra in the visible and near-infrared region, we find that the transmission spectra are highly tunable as the coupling and geometric parameters modifying, especially the third peak in the near-infrared region. When the gap distance between the two nanobar g1<14 nm, the original first peak will split, a new dip and peak will exist, which is results from the high-order plasmon resonance. When introducing asymmetry to the planer SRR, a new sharp peak accompany with a new sharp dip exists in the original second peak, which is originated from the strong electric field resonance. We also find that the proposed structures with sensing sensitivity of ~467 nm/RIU, which can be used for plasmonic sensor.

  3. Tunable multiple plasmon resonances and local field enhancement of nanocrescent/nanoring structure

    NASA Astrophysics Data System (ADS)

    Wang, Bin-Bing; Zhou, Jun; Chen, Dong; Fang, Yun-Tuan; Chen, Ming-Yang

    2015-08-01

    According to the plasmon hybridization theory, the plasmon resonance characteristics of the gold nanocrescent/nanoring (NCNR) structure are systematically investigated by the finite element method. It is found that the extinction spectra of NCNR structure exhibit multiple plasmon resonance peaks, which could be attributed to the result of the plasmon couplings between the multipolar plasmon modes of nanocrescent and the dipolar, quadrupolar, hexapolar, octupolar, decapolar plasmon modes of nanoring. By changing the geometric parameters, the intense and separate multiple plasmon resonance peaks are obtained and can be tuned in a wide wavelength range. It is further found that the plasmon coupling induces giant multipole electric field enhancements around the tips of the nanocrescent. The tunable and intense multiple plasmon resonances of NCNR structure may provide effective applications in multiplex biological sensing. Project supported by the National Natural Science Foundation of China (Grant Nos. 61275153 and 61320106014), the Natural Science Foundation of Zhejiang Province, China (Grant No. LY12A04002), the Natural Science Foundation of Ningbo City, China (Grant Nos. 2010D10018 and 2012A610107), and the K. C. Wong Magna Foundation of Ningbo University, China.

  4. Surface Plasmon Resonance Effect in Inverted Perovskite Solar Cells.

    PubMed

    Cui, Jin; Chen, Cheng; Han, Junbo; Cao, Kun; Zhang, Wenjun; Shen, Yan; Wang, Mingkui

    2016-03-01

    This work reports on incorporation of spectrally tuned gold/silica (Au/SiO2) core/shell nanospheres and nanorods into the inverted perovskite solar cells (PVSC). The band gap of hybrid lead halide iodide (CH3NH3PbI3) can be gradually increased by replacing iodide with increasing amounts of bromide, which can not only offer an appreciate solar radiation window for the surface plasmon resonance effect utilization, but also potentially result in a large open circuit voltage. The introduction of localized surface plasmons in CH3NH3PbI2.85Br0.15-based photovoltaic system, which occur in response to electromagnetic radiation, has shown dramatic enhancement of exciton dissociation. The synchronized improvement in photovoltage and photocurrent leads to an inverted CH3NH3PbI2.85Br0.15 planar PVSC device with power conversion efficiency of 13.7%. The spectral response characterization, time resolved photoluminescence, and transient photovoltage decay measurements highlight the efficient and simple method for perovskite devices.

  5. Surface Plasmon Resonance Effect in Inverted Perovskite Solar Cells

    PubMed Central

    Cui, Jin; Chen, Cheng; Han, Junbo; Cao, Kun; Zhang, Wenjun; Shen, Yan

    2016-01-01

    This work reports on incorporation of spectrally tuned gold/silica (Au/SiO2) core/shell nanospheres and nanorods into the inverted perovskite solar cells (PVSC). The band gap of hybrid lead halide iodide (CH3NH3PbI3) can be gradually increased by replacing iodide with increasing amounts of bromide, which can not only offer an appreciate solar radiation window for the surface plasmon resonance effect utilization, but also potentially result in a large open circuit voltage. The introduction of localized surface plasmons in CH3NH3PbI2.85Br0.15‐based photovoltaic system, which occur in response to electromagnetic radiation, has shown dramatic enhancement of exciton dissociation. The synchronized improvement in photovoltage and photocurrent leads to an inverted CH3NH3PbI2.85Br0.15 planar PVSC device with power conversion efficiency of 13.7%. The spectral response characterization, time resolved photoluminescence, and transient photovoltage decay measurements highlight the efficient and simple method for perovskite devices. PMID:28174678

  6. Atomically precise gold nanocrystal molecules with surface plasmon resonance.

    PubMed

    Qian, Huifeng; Zhu, Yan; Jin, Rongchao

    2012-01-17

    Since Faraday's pioneering work on gold colloids, tremendous scientific research on plasmonic gold nanoparticles has been carried out, but no atomically precise Au nanocrystals have been achieved. This work reports the first example of gold nanocrystal molecules. Mass spectrometry analysis has determined its formula to be Au(333)(SR)(79) (R = CH(2)CH(2)Ph). This magic sized nanocrystal molecule exhibits fcc-crystallinity and surface plasmon resonance at approximately 520 nm, hence, a metallic nanomolecule. Simulations have revealed that atomic shell closing largely contributes to the particular robustness of Au(333)(SR)(79), albeit the number of free electrons (i.e., 333 - 79 = 254) is also consistent with electron shell closing based on calculations using a confined free electron model. Guided by the atomic shell closing growth mode, we have also found the next larger size of extraordinarily stability to be Au(~530)(SR)(~100) after a size-focusing selection--which selects the robust size available in the starting polydisperse nanoparticles. This work clearly demonstrates that atomically precise nanocrystal molecules are achievable and that the factor of atomic shell closing contributes to their extraordinary stability compared to other sizes. Overall, this work opens up new opportunities for investigating many fundamental issues of nanocrystals, such as the formation of metallic state, and will have potential impact on condensed matter physics, nanochemistry, and catalysis as well.

  7. Enhancing Surface Plasmon Resonance Detection Using Nanostructured Au Chips

    NASA Astrophysics Data System (ADS)

    Indutnyi, Ivan; Ushenin, Yuriy; Hegemann, Dirk; Vandenbossche, Marianne; Myn'ko, Victor; Lukaniuk, Mariia; Shepeliavyi, Petro; Korchovyi, Andrii; Khrystosenko, Roman

    2016-12-01

    The increase of the sensitivity of surface plasmon resonance (SPR) refractometers was studied experimentally by forming a periodic relief in the form of a grating with submicron period on the surface of the Au-coated chip. Periodic reliefs of different depths and spatial frequency were formed on the Au film surface using interference lithography and vacuum chalcogenide photoresists. Spatial frequencies of the grating were selected close to the conditions of Bragg reflection of plasmons for the working wavelength of the SPR refractometer and the used environment (solution of glycerol in water). It was found that the degree of refractometer sensitivity enhancement and the value of the interval of environment refractive index variation, Δ n, in which this enhancement is observed, depend on the depth of the grating relief. By increasing the depth of relief from 13.5 ± 2 nm to 21.0 ± 2 nm, Δ n decreased from 0.009 to 0.0031, whereas sensitivity increased from 110 deg./RIU (refractive index unit) for a standard chip up to 264 and 484 deg./RIU for the nanostructured chips, respectively. Finally, it was shown that the working range of the sensor can be adjusted to the refractive index of the studied environment by changing the spatial frequency of the grating, by modification of the chip surface or by rotation of the chip.

  8. Probing molecular junctions using surface plasmon resonance spectroscopy.

    PubMed

    Shimizu, Ken T; Pala, Ragip A; Fabbri, Jason D; Brongersma, Mark L; Melosh, Nicholas A

    2006-12-01

    The optical absorption spectra of nanometer-thick organic films and molecular monolayers sandwiched between two metal contacts have been measured successfully using surface plasmon resonance spectroscopy (SPRS). The electric field within metal-insulator (organic)-metal (MIM) cross-bar junctions created by surface plasmon-polaritons excited on the metal surface allows sensitive measurement of molecular optical properties. Specifically, this spectroscopic technique extracts the real and imaginary indices of the organic layer for each wavelength of interest. The SPRS sensitivity was calculated for several device architectures, metals, and layer thicknesses to optimize the organic film absorptivity measurements. Distinct optical absorption features were clearly observed for R6G layers as thin as a single molecular monolayer between two metal electrodes. This method also enables dynamic measurement of molecular conformation inside metallic junctions, as shown by following the optical switching of a thin spiropyran/polymer film upon exposure to UV light. Finally, optical and electrical measurements can be made simultaneously to study the effect of electrical bias and current on molecular conformation, which may have significant impact in areas such as molecular and organic electronics.

  9. Geometric Dependence of the Line Width of Localized Surface Plasmon Resonances.

    PubMed

    Li, Yang; Zhao, Ke; Sobhani, Heidar; Bao, Kui; Nordlander, Peter

    2013-04-18

    For the same number of electrons and plasmon frequencies, longitudinal plasmon resonances in metallic nanorods exhibit narrower line widths than plasmon modes in spherical particles. We show that this property is a general feature of high aspect ratio nanostructures and can be explained very simply by incorporating retardation effects into a harmonic oscillator model. The origin of the effect is dynamic depolarization, which renormalizes the mass of the electrons and the oscillating electron liquid. The scattering spectrum derived from our model agrees very well with FDTD simulations. Because plasmon damping determines many important features and applications of LSPR, such as the Q factor of plasmonics devices and the magnitude of the induced field enhancements, our study will play an important role for the design of nanostructures with narrow plasmon resonances.

  10. Resonant wedge-plasmon modes in single-crystalline gold nanoplatelets

    NASA Astrophysics Data System (ADS)

    Gu, Lin; Sigle, Wilfried; Koch, Christoph T.; Ögüt, Burcu; van Aken, Peter A.; Talebi, Nahid; Vogelgesang, Ralf; Mu, Jianlin; Wen, Xiaogang; Mao, Jian

    2011-05-01

    Using energy-filtered transmission electron microscopy we measured surface-plasmon resonances of gold nanoplatelets with different shapes and edge lengths at high spatial resolution. We find equidistant maxima of the energy-loss probability along the platelet edges. The plasmon dispersion of the different geometries is very similar, i.e., hardly dependent on specimen shape. The experimental results are verified by means of finite-difference time-domain calculations which reveal the presence of wedge-plasmon polaritons propagating along the platelet edges. At platelet corners, apart from radiative losses, wedge-plasmon polaritons are partially reflected or transmitted to neighboring edges. The interference of all these contributions leads to the observed plasmon resonance modes. This is an essential step towards a thorough understanding of plasmon eigenmodes in prismatic nanoplatelets.

  11. Evanescent field enhancement due to plasmonic resonances of a metamaterial slab.

    PubMed

    Chiu, K P; Kao, T S; Tsai, D P

    2008-02-01

    The characteristics of plasmonic resonance in a dielectric-sandwiched metamaterial film at visible wavelengths of 650 and 568 nm have been investigated (for both p- and s-polarized light). Our calculated results demonstrate that each mode of plasmonic resonance has maximum resonance strength at a particular film thickness of the metamaterial. We also demonstrated that the effect of evanescent field enhancement is due to plasmonic resonances of the sandwiched metamaterial system. And the stronger the plasmonic resonance strength the larger the evanescent field is enhanced at the interfaces of the metamaterial film. Also we see that the plasmonic resonances in a sandwiched metamaterial are influenced not only by the materials that constitute the interfaces but also by the thickness of surrounding dielectrics or distance between evanescent light source and metamaterial film. Finally, our results show that there might be an effective light propagation length that will let the coupling efficiency between evanescent light source and SPs resonance become a maximum. These properties of plasmonic resonances to structure parameters of metamaterial film and its surrounding dielectrics provide a useful way to control the optical responses of an optoelectronic device when the wavelength of light source is fixed. That is, by suitably choosing light polarizations, thickness of the metamaterial thin film or the surrounding dielectrics and the position of evanescent light source, it is possible to modulate the plasmonic resonance wavenumber or resonance strength of the system. Therefore, the optical responses of the system can be modulated. Our results will be helpful for the structure design to control the behaviours of coupled plasmonic resonances and consequently the optical properties of the dielectric-sandwiched metamaterial film.

  12. Substrate-Supported Phospholipid Membranes Studied by Surface Plasmon Resonance and Surface Plasmon Fluorescence Spectroscopy

    PubMed Central

    Tawa, Keiko; Morigaki, Kenichi

    2005-01-01

    Substrate-supported planar lipid bilayer membranes are attractive model cellular membranes for biotechnological applications such as biochips and sensors. However, reliable fabrication of the lipid membranes on solid surfaces still poses significant technological challenges. In this study, simultaneous surface plasmon resonance (SPR) and surface plasmon fluorescence spectroscopy (SPFS) measurements were applied to the monitoring of adsorption and subsequent reorganization of phospholipid vesicles on solid substrates. The fluorescence intensity of SPFS depends very sensitively on the distance between the gold substrate and the fluorophore because of the excitation energy transfer to gold. By utilizing this distance dependency, we could obtain information about the topography of the adsorbed membranes: Adsorbed vesicles could be clearly distinguished from planar bilayers due to the high fluorescence intensity. SPSF can also incorporate various analytical techniques to evaluate the physicochemical properties of the adsorbed membranes. As an example, we demonstrated that the lateral mobility of lipid molecules could be estimated by observing the recovery of fluorescence after photobleaching. Combined with the film thickness information obtained by SPR, SPR-SPFS proved to be a highly informative technique to monitor the lipid membrane assembly processes on solid substrates. PMID:16040759

  13. Substrate-supported phospholipid membranes studied by surface plasmon resonance and surface plasmon fluorescence spectroscopy.

    PubMed

    Tawa, Keiko; Morigaki, Kenichi

    2005-10-01

    Substrate-supported planar lipid bilayer membranes are attractive model cellular membranes for biotechnological applications such as biochips and sensors. However, reliable fabrication of the lipid membranes on solid surfaces still poses significant technological challenges. In this study, simultaneous surface plasmon resonance (SPR) and surface plasmon fluorescence spectroscopy (SPFS) measurements were applied to the monitoring of adsorption and subsequent reorganization of phospholipid vesicles on solid substrates. The fluorescence intensity of SPFS depends very sensitively on the distance between the gold substrate and the fluorophore because of the excitation energy transfer to gold. By utilizing this distance dependency, we could obtain information about the topography of the adsorbed membranes: Adsorbed vesicles could be clearly distinguished from planar bilayers due to the high fluorescence intensity. SPSF can also incorporate various analytical techniques to evaluate the physicochemical properties of the adsorbed membranes. As an example, we demonstrated that the lateral mobility of lipid molecules could be estimated by observing the recovery of fluorescence after photobleaching. Combined with the film thickness information obtained by SPR, SPR-SPFS proved to be a highly informative technique to monitor the lipid membrane assembly processes on solid substrates.

  14. Noninvasive and Real-Time Plasmon Waveguide Resonance Thermometry

    PubMed Central

    Zhang, Pengfei; Liu, Le; He, Yonghong; Zhou, Yanfei; Ji, Yanhong; Ma, Hui

    2015-01-01

    In this paper, the noninvasive and real-time plasmon waveguide resonance (PWR) thermometry is reported theoretically and demonstrated experimentally. Owing to the enhanced evanescent field and thermal shield effect of its dielectric layer, a PWR thermometer permits accurate temperature sensing and has a wide dynamic range. A temperature measurement sensitivity of 9.4 × 10−3 °C is achieved and the thermo optic coefficient nonlinearity is measured in the experiment. The measurement of water cooling processes distributed in one dimension reveals that a PWR thermometer allows real-time temperature sensing and has potential to be applied for thermal gradient analysis. Apart from this, the PWR thermometer has the advantages of low cost and simple structure, since our transduction scheme can be constructed with conventional optical components and commercial coating techniques. PMID:25871718

  15. Sensing a heart infarction marker with surface plasmon resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Kunz, Ulrich; Katerkamp, Andreas; Renneberg, Reinhard; Spener, Friedrich; Cammann, Karl

    1995-02-01

    In this study a direct immunosensor for heart-type fatty acid binding protein (FABP) based on surface plasmon resonance spectroscopy (SPRS) is presented. FABP can be used as a heart infarction marker in clinical diagnostics. The development of a simple and cheap direct optical sensor device is reported in this paper as well as immobilization procedures and optimization of the measuring conditions. The correct working of the SPRS device is controlled by comparing the signals with theoretical calculated values. Two different immunoassay techniques were optimized for a sensitive FABP-analysis. The competitive immunoassay was superior to the sandwich configuration as it had a lower detection limit (100 ng/ml), needed less antibodies and could be carried out in one step.

  16. Optofluidic cellular immunofunctional analysis by localized surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Kurabayashi, Katsuo; Oh, Bo-Ram

    2014-08-01

    Cytokine secretion assays provide the means to quantify intercellular-signaling proteins secreted by blood immune cells. These assays allow researchers and clinicians to obtain valuable information on the immune status of the donor. Previous studies have demonstrated that localized surface plasmon resonance (LSPR) effects enable label-free, real-time biosensing on a nanostructured metallic surface with simple optics and sensing tunability. However, limited sensitivity coupled with a lack of sample handling capability makes it challenging to implement LSPR biosensing in cellular functional immunoanalysis based on cytokine secretion assay. This paper describes our recent progress towards full development of a label-free LSPR biosensing technique to detect cell-secreted tumor necrosis factor (TNF)-α cytokines in clinical blood samples. We integrate LSPR bionanosensors in an optofluidic platform capable of handling target immune cells in a microfluidic chamber while readily permitting optical access for cytokine detection.

  17. Surface plasmon resonance based biosensor technique: a review.

    PubMed

    Guo, Xiaowei

    2012-07-01

    Optical Surface plasmon resonance (SPR) biosensors represent the most advanced and developed optical label-free biosensor technology. Optical SPR biosensors are a powerful detection and analysis tool that has vast applications in environmental protection, biotechnology, medical diagnostics, drug screening, food safety and security. This article reviews the recent development of SPR biosensor techniques, including bulk SPR and localized SPR (LSPR) biosensors, for detecting interactions between an analyte of interest in solution and a biomolecular recognition. The concepts of bulk and localized SPs and the working principles of both sensing techniques are introduced. Major sensing advances on biorecognition elements, measurement formats, and sensing platforms are presented. Finally, the discussions on both biosensor techniques as well as comparison of both SPR sensing techniques are made.

  18. Surface plasmon resonance based infrared photo-detectors

    NASA Astrophysics Data System (ADS)

    Aytac, Yigit; Perera, Unil

    2012-03-01

    At present materials can be engineered to control propagation of light in certain directions at certain wavelengths. Such materials are called photonic crystals which contain a periodic arrangement of metals and dielectric materials on a wavelength scale. Surface Plasmon Resonances (SPR) in metallic and dielectric nano-arrays can be used to enhance the response of photo-detectors. There are variety of potential ways to increase the performance of infrared photo-detectors by using electromagnetic enhancement and dependence of the resonance wavelength on the arrays size, shape and the local dielectric environment integration of these apertures. A detailed analysis of the optical properties of the waveguides in two and three dimensions with periodically perforated array structures is presented. Transmission and reflection spectra, resonant modes and field patterns of photonic crystals were calculated and imaged with using FDTD (Finite-difference Time-domain) method by numerical analysis of the non-linear dispersion relation. Additionally, by varying the orientation of holes on the wave-guide, polarization sensitivity was achieved in the model.

  19. All-optical nonlinear plasmonic ring resonator switches

    NASA Astrophysics Data System (ADS)

    Nozhat, N.; Granpayeh, N.

    2014-11-01

    In this paper, all-optical nonlinear plasmonic ring resonator (PRR) switches containing 90o sharp and smooth bends have been proposed and numerically analyzed by the finite-difference time-domain method. Kerr nonlinear self-phase modulation (SPM) and cross-phase modulation (XPM) effects on the switching performance of the device have been studied. By applying a high-power lightwave, the signal can switch from one port to the other port due to the ON/OFF resonant states of the ring. We have shown that by utilizing the XPM effect, the output power ratio is improved by a factor of 2.5 and the required switching power is 31% of that of the case with only the SPM effect. Moreover, by utilizing sharp bend square-shaped ring resonators, the switching power is 10.4% lower than that of the smooth ones. The nonlinear PRR switches are suitable for application in photonic-integrated circuits as all-optical switches because of their nanoscale size and low required switching power.

  20. Theory and Applications of Surface Plasmon Resonance, Resonant Mirror, Resonant Waveguide Grating, and Dual Polarization Interferometry Biosensors

    PubMed Central

    Daghestani, Hikmat N.; Day, Billy W.

    2010-01-01

    Biosensors have been used extensively in the scientific community for several purposes, most notably to determine association and dissociation kinetics, protein-ligand, protein-protein, or nucleic acid hybridization interactions. A number of different types of biosensors are available in the field, each with real or perceived benefits over the others. This review discusses the basic theory and operational arrangements of four commercially available types of optical biosensors: surface plasmon resonance, resonant mirror, resonance waveguide grating, and dual polarization interferometry. The different applications these techniques offer are discussed from experiments and results reported in recently published literature. Additionally, recent advancements or modifications to the current techniques are also discussed. PMID:22163431

  1. Characteristics of double-plasmonic-racetrack resonator to increase quality factor

    NASA Astrophysics Data System (ADS)

    Okamoto, Hiroyuki; Onishi, Sei; Kataoka, Mai; Yamaguchi, Kenzo; Haraguchi, Masanobu; Okamoto, Toshihiro

    2013-01-01

    We have numerically evaluated wavelength characteristics at telecommunication wavelengths by means of a doubleplasmonic-racetrack resonator using the finite-difference time domain method. We investigated the effect of the space between the two plasmonic racetracks of the resonator on the quality factor. The quality factor of the proposed structure is 57 when the space between two racetracks is 600 nm. The quality factor of a double-plasmonic-racetrack resonator of a dielectric-filled trench is 1.5 times greater than that of a single-plasmonic-racetrack resonator of an air-filled trench. The phase mismatch of the trench channel plasmon polaritons contributes to the quality factor of the double-plasmonicracetrack resonator.

  2. Plasmon resonances in a stacked pair of graphene ribbon arrays with a lateral displacement.

    PubMed

    He, Meng-Dong; Zhang, Gui; Liu, Jian-Qiang; Li, Jian-Bo; Wang, Xin-Jun; Huang, Zhen-Rong; Wang, Lingling; Chen, Xiaoshuang

    2014-03-24

    We find that a stacked pair of graphene ribbon arrays with a lateral displacement can excite plasmon waveguide mode in the gap between ribbons, as well as surface plasmon mode on graphene ribbon surface. When the resonance wavelengthes of plasmon waveguide mode and surface plasmon mode are close to each other, there is a strong electromagnetic interaction between the two modes, and then they contribute together to transmission dip. The plasmon waveguide mode resonance can be manipulated by the lateral displacement and longitudinal interval between arrays due to their influence on the manner and strength of electromagnetic coupling between two arrays. The findings expand our understanding of electromagnetic resonances in graphene-ribbon array structure and may affect further engineering of nanoplasmonic devices and metamaterials.

  3. Fano resonances in the nonlinear optical response of coupled plasmonic nanostructures.

    PubMed

    Butet, Jérémy; Martin, Olivier J F

    2014-12-01

    The coupling between metallic nanostructures is a common and easy way to control the optical properties of plasmonic systems. Even though the coupling between plasmonic oscillators has been widely studied in the linear regime, its influence on the nonlinear optical response of metallic nanostructures has been sparsely considered. Using a surface integral equation method, we investigate the second order nonlinear optical response of plasmonic metamolecules supporting Fano resonances revealing that the typical lineshape of Fano resonances is also clearly observable in the nonlinear regime. The physical mechanisms leading to nonlinear Fano resonances are revealed by the coupled oscillator model and the symmetry subgroup decomposition. It is found that the origin of the nonlinear scattered wave, i. e. the active plasmonic oscillator, can be selectively chosen. Furthermore, interferences between nonlinear emissions are clearly observed in specific configurations. The results presented in this article pave the way for the design of efficient nonlinear plasmonic metamolecules with controlled nonlinear radiation.

  4. Limitations of a localized surface plasmon resonance sensor on Salmonella detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have designed a localized surface plasmon resonance (LSPR) biosensor to perform the whole cell detection of Salmonella using gold nanoparticls fabricated by oblique angle deposition technique. The LSPR sensor showed a plasmon peak shift due to the Salmonella antigen and anti-Salmonella antibody r...

  5. Ultra-sharp plasmonic resonances from monopole optical nanoantenna phased arrays

    SciTech Connect

    Li, Shi-Qiang; Bruce Buchholz, D.; Zhou, Wei; Ketterson, John B.; Ocola, Leonidas E.; Sakoda, Kazuaki; Chang, Robert P. H.

    2014-06-09

    Diffractively coupled plasmonic resonances possess both ultra-sharp linewidths and giant electric field enhancement around plasmonic nanostructures. They can be applied to create a new generation of sensors, detectors, and nano-optical devices. However, all current designs require stringent index-matching at the resonance condition that limits their applicability. Here, we propose and demonstrate that it is possible to relieve the index-matching requirement and to induce ultra-sharp plasmon resonances in an ordered vertically aligned optical nano-antenna phased array by transforming a dipole resonance to a monopole resonance with a mirror plane. Due to the mirror image effect, the monopole resonance not only retained the dipole features but also enhanced them. The engineered resonances strongly suppressed the radiative decay channel, resulting in a four-order of magnitude enhancement in local electric field and a Q-factor greater than 200.

  6. The preparation of a plasmonically resonant VO2 thermochromic pigment

    NASA Astrophysics Data System (ADS)

    Bai, Huaping; Cortie, Michael B.; Maaroof, Abbas I.; Dowd, Annette; Kealley, Catherine; Smith, Geoffrey B.

    2009-02-01

    Vanadium dioxide (VO2) undergoes a reversible metal-insulator transition, normally at ~68 °C. While the properties of continuous semi-transparent coatings of VO2 are well known, there is far less information available concerning the potential use of discrete VO2 nanoparticles as a thermochromic pigment in opaque coatings. Individual VO2 nanoparticles undergo a localized plasmon resonance with near-infrared light at about 1100 nm and this resonance can be switched on and off by simply varying the temperature of the system. Therefore, incorporation of VO2 nanoparticles into a coating system imbues the coating with the ability to self-adaptively modulate its own absorptive efficiency in the near-infrared. Here we examine the magnitude and control of this phenomenon. Prototype coatings are described, made using VO2 powder produced by an improved process. The materials are characterized using calorimetry, x-ray diffraction, high-resolution scanning electron microscopy, transmission electron microscopy, and by measurement of optical properties.

  7. Collective electric and magnetic plasmonic resonances in spherical nanoclusters.

    PubMed

    Vallecchi, Andrea; Albani, Matteo; Capolino, Filippo

    2011-01-31

    We report an investigation on the optical properties of three-dimensional nanoclusters (NCs) made by spherical constellations of metallic nanospheres arranged around a central dielectric sphere, which can be realized and assembled by current state-of-the-art nanochemistry techniques. This type of NCs supports collective plasmon modes among which the most relevant are those associated with the induced electric and magnetic resonances. Combining a single dipole approximation for each nanoparticle and the multipole spherical-wave expansion of the scattered field, we achieve an effective characterization of the optical response of individual NCs in terms of their scattering, absorption, and extinction efficiencies. By this approximate model we analyze a few sample NCs identifying the electric and magnetic resonance frequencies and their dependence on the size and number of the constituent nanoparticles. Furthermore, we discuss the effective electric and magnetic polarizabilities of the NCs, and their isotropic properties. A homogenization method based on an extension of the Maxwell Garnett model to account for interaction effects due to higher order multipoles in dense packed arrays is applied to a distribution of NCs showing the possibility of obtaining metamaterials with very large, small, and negative values of permittivity and permeability, and even negative index.

  8. Design and manufacture of angle modulated surface plasmon resonance spectrometer

    NASA Astrophysics Data System (ADS)

    Zhou, Xinlei; Chen, Ke; Mao, Xuefeng; Yu, Qingxu; Peng, Wei

    2015-08-01

    As an emerging biosensing technology, Surface Plasmon Resonance (SPR) technique, characterized by high sensitivity, label-free detection and real-time monitoring, has been extensively applied in biochemical analysis, environmental monitoring and refractive index measurement. In this paper, an angle modulated SPR spectrometer with high resolution is designed and manufactured. First, according to the modeling and simulation for the SPR spectrometer, several key parameters such as the light source, the thickness of golden film and Cr film are determined. Then, an angle modulated SPR spectrometer system based on 5-layers Kretchmann prism structure is developed for biochemical analysis. System performance is tested after the SPR spectrometer established. We test the power stability of the laser first, which is up to 1.504% (5min). Different concentrations of glycerol are measured to demarcate the system. Then, we measured the deionized water ten times continuously, and a resolution of 1.5×10-5 RIU is achieved. At last, different concentrations of glucose solution are measured, and the resonance angles are used to calculate the refractive index of the glucose solutions, which is more accurate than the result of Abbe refractometer. The relationship between concentration and refractive index is presented by liner fitting.

  9. Regulating the surface plasmon resonance coupling between Au-nanoparticle and Au-film

    NASA Astrophysics Data System (ADS)

    Wang, Shuang; Li, Kewu; Zhang, Rui; Jing, Ning; Chen, Youhua; Chen, Yuanyuan; Wang, Zhibin

    2017-01-01

    In this paper, we report the coupling between the localized surface plasmon resonance (LSPR) of Au-nanoparticles and surface plasmon resonance (SPR) of the Au-film. According to the conditions for SPR excitation of the classical Kretschmann-Raether structure with 50nm Au thin film, the commonly used classes of spherical Au-nanoparticle is studied and optimized. We used the finite element analysis (COMSOL Multiphysics 5.0), to simulate the coupling. The results from calculation and simulation indicate that the resonant plasmonic coupling between Au-nanoparticles and Au-film could lead to a large field enhancement and thus improve SPR. We demonstrate that the resonant plasmonic coupling could be regulated by the size of nanoparticles, the distance between nanoparticles .

  10. Highly sensitive surface plasmon resonance chemical sensor based on Goos-Hanchen effects

    NASA Astrophysics Data System (ADS)

    Yin, Xiaobo; Hesselink, Lambertus

    2006-08-01

    The resonance enhanced Goos-Hanchen shifts at attenuated total internal reflection enables the possibility for highly sensitive surface plasmon resonance sensor. The observed giant displacements result from the singular phase retardation at the resonance where the phase is continuous but changes dramatically. The phenomenon is proposed for chemical sensing and the superior sensitivity is demonstrated.

  11. Detection of methane by a surface plasmon resonance sensor based on polarization interferometry and angle modulation

    NASA Astrophysics Data System (ADS)

    Liu, Le; Hu, Zhaoxu; Ma, Suihua; Zhang, Ying; He, Yonghong; Guo, Jihua

    2010-12-01

    A novel methane sensor based on surface plasmon resonance is presented. An isoprene rubber (IPR) film is used as the sensing layer for methane. With the technologies of polarization interferometry and angle modulation, a detecting resolution of 700 ppm is achieved, which is better than previously reported methane sensors based on surface plasmon resonance and has a potential to be improved. The technique could have potential applications in monitoring methane concentrations.

  12. Tunable multipole resonances in plasmonic crystals made by four-beam holographic lithography

    SciTech Connect

    Luo, Y.; Li, X.; Zhang, X.; Prybolsky, S.; Shepard, G. D.; Strauf, S.

    2016-02-01

    Plasmonic nanostructures confine light to sub-wavelength scales, resulting in drastically enhanced light-matter interactions. Recent interest has focused on controlled symmetry breaking to create higher-order multipole plasmonic modes that store electromagnetic energy more efficiently than dipole modes. Here we demonstrate that four-beam holographic lithography enables fabrication of large-area plasmonic crystals with near-field coupled plasmons as well as deliberately broken symmetry to sustain multipole modes and Fano-resonances. Compared with the spectrally broad dipole modes we demonstrate an order of magnitude improved Q-factors (Q = 21) when the quadrupole mode is activated. We further demonstrate continuous tuning of the Fano-resonances using the polarization state of the incident light beam. The demonstrated technique opens possibilities to extend the rich physics of multipole plasmonic modes to wafer-scale applications that demand low-cost and high-throughput.

  13. Grating-coupled surface plasmon resonance in conical mounting with polarization modulation.

    PubMed

    Ruffato, G; Romanato, F

    2012-07-01

    A grating-coupled surface plasmon resonance (GCSPR) technique based on polarization modulation in conical mounting is presented. A metallic grating is azimuthally rotated to support double-surface plasmon polariton excitation and exploit the consequent sensitivity enhancement. Corresponding to the resonance polar angle, a polarization scan of incident light is performed, and reflectivity data are collected before and after functionalization with a dodecanethiol self-assembled monolayer. The output signal exhibits a harmonic dependence on polarization, and the phase term is used as a parameter for sensing. This technique offers the possibility of designing extremely compact, fast, and cheap high-resolution plasmonic sensors based on GCSPR.

  14. Sideways scattering in double resonant plasmonic nanostructures for light harvesting applications.

    PubMed

    Achermann, Marc

    2016-12-26

    Numerical simulations of light scattering by elongated metal nanoparticles in an asymmetric arrangement show resonant scattering in two near-infrared wavelength ranges associated with different surface plasmon modes. The main scattering directions of the two plasmon modes are in opposite diagonal directions and almost perpendicular to each other. At wavelengths in-between the two plasmon resonances our simulations showed for the first time strong scattering at approximately ± 90°, which is parallel to the incident electric field direction. Since enhanced sideways scattering exists over a significant wavelength range, the proposed nanoparticle assemblies could be beneficial for light harvesting applications such as solar windows.

  15. Analogue of electromagnetically induced transparency in integrated plasmonics with radiative and subradiant resonators.

    PubMed

    Wang, Ting; Zhang, Yusheng; Hong, Zhi; Han, Zhanghua

    2014-09-08

    We propose the use of radiative and subradiant resonators coupled to a metal-insulator-metal waveguide to represent the three-level energy diagram in conventional atomic systems and demonstrate a new realization of on-chip plasmonic analogue of electromagnetically-induced transparency (EIT) in integrated plasmonics. The radiative resonator is achieved with the help of aperture-coupling while evanescent coupling is relied for the subradiant resonator. Numerical simulation results demonstrate well-pronounced intermediate transmission peak through the bus waveguide and also show that the EIT effect can be easily controlled by the relative position of the two Fabry-Perot resonators.

  16. Composite modulation of Fano resonance in plasmonic microstructures by electric-field and microcavity

    SciTech Connect

    Zhang, Fan; Wu, Chenyun; Yang, Hong; Hu, Xiaoyong Gong, Qihuang

    2014-11-03

    Composite modulation of Fano resonance by using electric-field and microcavity simultaneously is realized in a plasmonic microstructure, which consists of a gold nanowire grating inserted into a Fabry-Perot microcavity composited of a liquid crystal layer sandwiched between two indium tin oxide layers. The Fano resonance wavelength varies with the applied voltage and the microcavity resonance. A large shift of 48 nm in the Fano resonance wavelength is achieved when the applied voltage is 20 V. This may provide a new way for the study of multi-functional integrated photonic circuits and chips based on plasmonic microstructures.

  17. Localized surface plasmon resonance modes on an asymmetric cylindrical nanorod dimer

    NASA Astrophysics Data System (ADS)

    Wang, Rui-Bing; Zhang, Zhi-Dong; Jiao, Guo-Tai; Xue, Chen-Yang; Yan, Shu-Bin; Wang, Hongyang

    2016-08-01

    The extinction spectra and electric field distribution of an asymmetric cylindrical nanorod dimer (ACND) are calculated by discrete dipole approximation. The ACND is composed of two linear orders of cylindrical silver nanorods with different radii and lengths. The effects of the structural parameters of ACND on the localized surface plasmon resonance (LSPR) mode are also studied. Results show two resonance peaks in the extinction spectra of ACND: the higher-energy anti-bonding mode and the lower-energy bonding mode. The interaction of two hybridization plasmonic resonance modes produces an asymmetric line shape in the extinction spectra, which is considered to be a Fano resonance profile.

  18. Excitation and tuning of Fano-like cavity plasmon resonances in dielectric-metal core-shell resonators

    NASA Astrophysics Data System (ADS)

    Gu, Ping; Wan, Mingjie; Wu, Wenyang; Chen, Zhuo; Wang, Zhenlin

    2016-05-01

    Fano resonances have been realized in plasmonic systems and have found intriguing applications, in which, however, precisely controlled symmetry breaking or particular arrangement of multiple constituents is usually involved. Although simple core-shell type architectures composed of a spherical dielectric core and a concentric metallic shell layer have been proposed as good candidates that support inherent Fano resonances, these theoretical predictions have rarely seen any detailed experimental investigation. Here, we report on the experimental investigation of the magnetic and electric-based multipolar plasmonic Fano resonances in the dielectric-metal core-shell resonators that are formed by wrapping a nearly perfect metal shell layer around a dielectric sphere. We demonstrate that these Fano resonances originate from the interference between the Mie cavity and sphere plasmon resonances. Moreover, we present that the variation on either the dielectric core size or core refractive index allows for easily tuning the observed Fano resonances over a wide spectral range. Our findings are supported by excellent agreement with analytical calculations, and offer unprecedented opportunities for realizing ultrasensitive bio-sensors, lasing and nonlinear optical devices.Fano resonances have been realized in plasmonic systems and have found intriguing applications, in which, however, precisely controlled symmetry breaking or particular arrangement of multiple constituents is usually involved. Although simple core-shell type architectures composed of a spherical dielectric core and a concentric metallic shell layer have been proposed as good candidates that support inherent Fano resonances, these theoretical predictions have rarely seen any detailed experimental investigation. Here, we report on the experimental investigation of the magnetic and electric-based multipolar plasmonic Fano resonances in the dielectric-metal core-shell resonators that are formed by wrapping a

  19. Electrical detection of surface plasmon resonance phenomena by a photoelectronic device integrated with gold nanoparticle plasmon antenna

    NASA Astrophysics Data System (ADS)

    Hashimoto, Tatsuya; Fukunishi, Yurie; Zheng, Bin; Uraoka, Yukiharu; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji

    2013-02-01

    We have proposed a concept of a photoelectronic hybrid device utilizing gold nanoparticles (GNPs), which are supposed to function not only as the plasmon antenna but also as the sensing part. The photocurrent in the fabricated device, consisting of a transparent Nb-doped TiO2 channel and Au electrodes, was enhanced more than eight times at a specific wavelength with GNP arrays located between the electrodes, indicating that surface plasmon resonance was electrically detected with the hybrid device. This result will open new doors for ultra-small biosensor chips integrated with multi-functional solid-state devices.

  20. Gallium arsenide based surface plasmon resonance for glucose monitoring

    NASA Astrophysics Data System (ADS)

    Patil, Harshada; Sane, Vani; Sriram, G.; Indumathi, T. S; Sharan, Preeta

    2015-07-01

    The recent trends in the semiconductor and microwave industries has enabled the development of scalable microfabrication technology which produces a superior set of performance as against its counterparts. Surface Plasmon Resonance (SPR) based biosensors are a special class of optical sensors that become affected by electromagnetic waves. It is found that bio-molecular recognition element immobilized on the SPR sensor surface layer reveals a characteristic interaction with various sample solutions during the passage of light. The present work revolves around developing painless glucose monitoring systems using fluids containing glucose like saliva, urine, sweat or tears instead of blood samples. Non-invasive glucose monitoring has long been simulated using label free detection mechanisms and the same concept is adapted. In label-free detection, target molecules are not labeled or altered, and are detected in their natural forms. Label-free detection mechanisms involves the measurement of refractive index (RI) change induced by molecular interactions. These interactions relates the sample concentration or surface density, instead of total sample mass. After simulation it has been observed that the result obtained is highly accurate and sensitive. The structure used here is SPR sensor based on channel waveguide. The tools used for simulation are RSOFT FULLWAVE, MEEP and MATLAB etc.

  1. Spectral phase-shift detection of surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Duliakova, M.; Hlubina, P.; Ciprian, D.

    2016-12-01

    A two-step spectral interferometric technique to detect the spectral phase shift of surface plasmon resonance (SPR) in the Kretschmann configuration is proposed and demonstrated. The technique utilizes a polarimetry setup to record two channeled spectra, one including reflection of p- and s-polarized waves from an SPR structure for air when the SPR phenomenon does not occur, and the other one for an analyte when the SPR phenomenon occurs. The channeled spectra are used to detect the SPR spectral phase shift and first, an SF10 glass prism and a gold coated SF10 slide with a chromium adhesion layer is used to measure the SPR phase shift for aqueous solutions of ethanol. In addition, the position of a sharp maximum in the spectral derivative of the SPR phase shift is measured as a function of the analyte parameter. Second, the setup with a gold coated SF10 glass prism is used to measure the SPR phase shift for the same analyte. It is revealed that the detection accuracy of the measurement of the spectral derivative of the SPR phase shift in the second setup is lower than that in the first setup. For the first case, the measurements are accompanied by theoretical modeling of the SPR responses using the material dispersion characteristics.

  2. Surface Plasmon Resonance Biosensor Based on Smart Phone Platforms.

    PubMed

    Liu, Yun; Liu, Qiang; Chen, Shimeng; Cheng, Fang; Wang, Hanqi; Peng, Wei

    2015-08-10

    We demonstrate a fiber optic surface plasmon resonance (SPR) biosensor based on smart phone platforms. The light-weight optical components and sensing element are connected by optical fibers on a phone case. This SPR adaptor can be conveniently installed or removed from smart phones. The measurement, control and reference channels are illuminated by the light entering the lead-in fibers from the phone's LED flash, while the light from the end faces of the lead-out fibers is detected by the phone's camera. The SPR-sensing element is fabricated by a light-guiding silica capillary that is stripped off its cladding and coated with 50-nm gold film. Utilizing a smart application to extract the light intensity information from the camera images, the light intensities of each channel are recorded every 0.5 s with refractive index (RI) changes. The performance of the smart phone-based SPR platform for accurate and repeatable measurements was evaluated by detecting different concentrations of antibody binding to a functionalized sensing element, and the experiment results were validated through contrast experiments with a commercial SPR instrument. This cost-effective and portable SPR biosensor based on smart phones has many applications, such as medicine, health and environmental monitoring.

  3. Surface Plasmon Resonance Biosensor Based on Smart Phone Platforms

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Liu, Qiang; Chen, Shimeng; Cheng, Fang; Wang, Hanqi; Peng, Wei

    2015-08-01

    We demonstrate a fiber optic surface plasmon resonance (SPR) biosensor based on smart phone platforms. The light-weight optical components and sensing element are connected by optical fibers on a phone case. This SPR adaptor can be conveniently installed or removed from smart phones. The measurement, control and reference channels are illuminated by the light entering the lead-in fibers from the phone’s LED flash, while the light from the end faces of the lead-out fibers is detected by the phone’s camera. The SPR-sensing element is fabricated by a light-guiding silica capillary that is stripped off its cladding and coated with 50-nm gold film. Utilizing a smart application to extract the light intensity information from the camera images, the light intensities of each channel are recorded every 0.5 s with refractive index (RI) changes. The performance of the smart phone-based SPR platform for accurate and repeatable measurements was evaluated by detecting different concentrations of antibody binding to a functionalized sensing element, and the experiment results were validated through contrast experiments with a commercial SPR instrument. This cost-effective and portable SPR biosensor based on smart phones has many applications, such as medicine, health and environmental monitoring.

  4. Surface plasmon resonance: instrumental resolution using photo diode arrays

    NASA Astrophysics Data System (ADS)

    Johansen, Knut; Stålberg, Ralph; Lundström, Ingemar; Liedberg, Bo

    2000-11-01

    Surface plasmon resonance (SPR) sensors are used to study biomolecular interactions. We have performed a theoretical analysis of a SPR instrument using a convergent beam, a linear detector with various numbers of pixels and various analogue-to-digital converters (ADCs) with a corresponding resolution ranging from 8 to 16 bits. Studies of small molecules at low concentrations or with low affinities are limited by the instrumental set-up, e.g. by the resolution, linearity and noise. The amplitudes of these parameters are highly dependent on the detector, ADC and dip-finding algorithm used. We have studied several dip-finding algorithms, e.g. intensity measurements, second- and third-order polynomial fits and centroid algorithms. Each algorithm used with the ADC and the detector has a resolution associated with it. Some algorithms also have an intrinsic algorithm error that is dependent on the number of pixels and the shape of the dip. A weighted centroid algorithm that has an excellent overall performance is described. If an accuracy of 10-6 refractive index units (RIU) is satisfactory, a 12-bit ADC and a 64-pixel detector are appropriate. Theoretically, by using a 16-bit ADC and a 1024-pixel detector, a resolution of better than 10-9 RIU is obtainable.

  5. Surface plasmon resonance spectroscopy sensor and methods for using same

    DOEpatents

    Anderson, Brian Benjamin; Nave, Stanley Eugene

    2002-01-01

    A surface plasmon resonance ("SPR") probe with a detachable sensor head and system and methods for using the same in various applications is described. The SPR probe couples fiber optic cables directly to an SPR substrate that has a generally planar input surface and a generally curved reflecting surface, such as a substrate formed as a hemisphere. Forming the SPR probe in this manner allows the probe to be miniaturized and operate without the need for high precision, expensive and bulky collimating or focusing optics. Additionally, the curved reflecting surface of the substrate can be coated with one or multiple patches of sensing medium to allow the probe to detect for multiple analytes of interest or to provide multiple readings for comparison and higher precision. Specific applications for the probe are disclosed, including extremely high sensitive relative humidity and dewpoint detection for, e.g., moisture-sensitive environment such as volatile chemical reactions. The SPR probe disclosed operates with a large dynamic range and provides extremely high quality spectra despite being robust enough for field deployment and readily manufacturable.

  6. Surface plasmon resonance biosensor for enzymatic detection of small analytes.

    PubMed

    Miyazaki, Celina Massumi; Shimizu, Flávio Makoto; Mejía-Salazar, J R; Oliveira, Osvaldo N; Ferreira, Marystela

    2017-04-07

    Surface plasmon resonance (SPR) biosensing is based on the detection of small changes in the refractive index on a gold surface modified with molecular recognition materials, thus being mostly limited to detecting large molecules. In this paper, we report on a SPR biosensing platform suitable to detect small molecules by making use of the mediator-type enzyme microperoxidase-11 (MP11) in layer-by-layer films. By depositing a top layer of glucose oxidase or uricase, we were able to detect glucose or uric acid with limits of detection of 3.4 and 0.27 μmol l(-1), respectively. Measurable SPR signals could be achieved because of the changes in polarizability of MP11, as it is oxidized upon interaction with the analyte. Confirmation of this hypothesis was obtained with finite difference time domain simulations, which also allowed us to discard the possible effects from film roughness changes observed in atomic force microscopy images. The main advantage of this mediator-type enzyme approach is in the simplicity of the experimental method that does not require an external potential, unlike similar approaches for SPR biosensing of small molecules. The detection limits reported here were achieved without optimizing the film architecture, and therefore the performance can in principle be further enhanced, while the proposed SPR platform may be extended to any system where hydrogen peroxide is generated in enzymatic reactions.

  7. Surface plasmon resonance immunosensor for cortisol and cortisone determination.

    PubMed

    Frasconi, Marco; Mazzarino, Monica; Botrè, Francesco; Mazzei, Franco

    2009-08-01

    In this paper, we present a surface-plasmon-resonance-based immunosensor for the real-time detection of cortisol and cortisone levels in urine and saliva samples. The method proposed here is simple, rapid, economic, sensitive, robust, and reproducible thanks also to the special features of the polycarboxylate-hydrogel-based coatings used for the antibody immobilization. The sensor surface displays a high level of stability during repeated regeneration and affinity reaction cycles. The immunosensor shows high specificity for cortisol and cortisone; furthermore, no significant interferences from other steroids with a similar chemical structure have been observed. The suitability of the hydrogel coating for the prevention of nonspecific binding is also investigated. A good correlation is noticed between the results obtained by the proposed method and the reference liquid chromatography/tandem mass spectrometry method for the analysis of cortisol and cortisone in urine and saliva samples. Standard curves for the detection of cortisol and cortisone in saliva and urine are characterized by a detection limit less than 10 microg l(-1), sufficiently sensitive for both clinical and forensic use.

  8. Surface Plasmon Resonance Biosensor Based on Smart Phone Platforms

    PubMed Central

    Liu, Yun; Liu, Qiang; Chen, Shimeng; Cheng, Fang; Wang, Hanqi; Peng, Wei

    2015-01-01

    We demonstrate a fiber optic surface plasmon resonance (SPR) biosensor based on smart phone platforms. The light-weight optical components and sensing element are connected by optical fibers on a phone case. This SPR adaptor can be conveniently installed or removed from smart phones. The measurement, control and reference channels are illuminated by the light entering the lead-in fibers from the phone’s LED flash, while the light from the end faces of the lead-out fibers is detected by the phone’s camera. The SPR-sensing element is fabricated by a light-guiding silica capillary that is stripped off its cladding and coated with 50-nm gold film. Utilizing a smart application to extract the light intensity information from the camera images, the light intensities of each channel are recorded every 0.5 s with refractive index (RI) changes. The performance of the smart phone-based SPR platform for accurate and repeatable measurements was evaluated by detecting different concentrations of antibody binding to a functionalized sensing element, and the experiment results were validated through contrast experiments with a commercial SPR instrument. This cost-effective and portable SPR biosensor based on smart phones has many applications, such as medicine, health and environmental monitoring. PMID:26255778

  9. Dual surface plasmon resonances in Ni nanoparticles in silica

    SciTech Connect

    Majhi, Jayanta K.; Kuiri, Probodh K.

    2015-06-24

    We report the observations of two broad absorption bands (at ∼3.5 and ∼6.0 eV) in the optical absorption (OA) spectra of Ni nanoparticles (NPs) in silica. For the calculations of the OA spectra, Maxwell-Garnett type effective medium theory has been used with NP radii in the range of 1 – 50 nm. The peak positions of both the OA bands have been found to shift towards higher energy (blue-shift) with decrease in NP radius. In addition, the OA spectra are found to more sensitive for smaller NPs as compare to larger NPs. These observations are argued as due to the confinement of the mean free path of free electrons in Ni NPs. Based on this, we conclude that the observed OA bands are due to the surface plasmon resonance (SPR) absorptions irrespective of the satisfaction of the criteria of the SPR conditions, thus resolving the unclear understanding of the appearance of two absorption bands in Ni NPs.

  10. Glucose measurement by surface plasmon resonance with borate polymer binding

    NASA Astrophysics Data System (ADS)

    Li, Dachao; Yang, Jia; Wu, Peng; Yang, Di; Wang, Bo; Lin, Yuan; Xu, Kexin

    2013-02-01

    Minimally-invasive human blood glucose detection can be realized by measuring the glucose concentration of interstitial fluid to predict the blood glucose level. As the amount of transdermally extracted interstitial fluid was minimal and its composition was complex, a glucose measurement method by surface plasmon resonance (SPR) based on PAA-ran-PAAPBA polymer binding was proposed. The polymer was immobilized on the gold film of SPR sensor using layer-by-layer self-assembly technique to capture the glucose molecules in interstitial fluid to realize the detection of glucose concentration with high precision. 2~1000mg/dL glucose solutions were measured utilizing the SPR sensor by polymer binding. The fitting degrees were 0.90177 and 0.99509 in the range of 2~10mg/dL and 25~1000mg/dL respectively. The dynamic dissociation process of glucose molecules from PAA-ran-PAAPBA was verified to be able to satisfy the requirements of the human blood glucose continuous monitoring in clinics.

  11. Novel localized surface plasmon resonance based optical fiber sensor

    NASA Astrophysics Data System (ADS)

    Muri, Harald Ian D. I.; Hjelme, Dag R.

    2016-03-01

    Over the last decade various optical fiber sensing schemes have been proposed based on local surface plasmon resonance (LSPR). LSPR are interacting with the evanescent field from light propagating in the fiber core or by interacting with the light at the fiber end face. Sensor designs utilizing the fiber end face is strongly preferred from a manufacturing point of view. However, the different techniques available to immobilize metallic nanostructures on the fiber end face for LSPR sensing is limited to essentially a monolayer, either by photolithographic structuring of metal film, thermal nucleation of metal film, or by random immobilization of nanoparticles (NP). In this paper, we report on a novel LSPR based optical fiber sensor architecture. The sensor is prepared by immobilizing gold NP's in a hydrogel droplet polymerized on the fiber end face. This design has several advantages over earlier designs. It dramatically increase the number of NP's available for sensing, it offers precise control over the NP density, and the NPs are position in a true 3D aqueous environment. The sensor design is also compatible with low cost manufacturing. The sensor design can measure volumetric changes in a stimuli-responsive hydrogel or measure binding to receptors on the NP surface. It can also be used as a two-parameter sensor by utilizing both effects. We present results from proof-of-concept experiments demonstrating a pH sensor based on LSPR sensing in a poly(acrylamide-co-acrylic acid) hydrogel embedding gold nanoparticles.

  12. Surface Plasmon Resonance: An Introduction to a Surface Spectroscopy Technique

    PubMed Central

    Tang, Yijun; Zeng, Xiangqun; Liang, Jennifer

    2010-01-01

    Surface plasmon resonance (SPR) has become an important optical biosensing technology in the areas of biochemistry, biology, and medical sciences because of its real-time, label-free, and noninvasive nature. The high cost of commercial devices and consumables has prevented SPR from being introduced in the undergraduate laboratory. Here we present an affordable homemade SPR device with all of its components accessible to visualization. This design allows ease of integration with electrochemistry and makes the device suitable for education. We describe a laboratory experiment in which students examine the relationship between the SPR angle and the solution refractive index at the interface and perform a coupled SPR–electrochemistry experiment. Students also study the antibody–antigen binding activity. Most of the experimental work was done as a project by a grade 12 high-school student under proper supervision. We believe that the SPR device and the SPR laboratory will enhance undergraduate chemical education by introducing students to this important modern instrumentation and will help students to learn and understand the molecular interactions occurring at interfaces. PMID:21359107

  13. Surface Plasmon Resonance: An Introduction to a Surface Spectroscopy Technique.

    PubMed

    Tang, Yijun; Zeng, Xiangqun; Liang, Jennifer

    2010-07-01

    Surface plasmon resonance (SPR) has become an important optical biosensing technology in the areas of biochemistry, biology, and medical sciences because of its real-time, label-free, and noninvasive nature. The high cost of commercial devices and consumables has prevented SPR from being introduced in the undergraduate laboratory. Here we present an affordable homemade SPR device with all of its components accessible to visualization. This design allows ease of integration with electrochemistry and makes the device suitable for education. We describe a laboratory experiment in which students examine the relationship between the SPR angle and the solution refractive index at the interface and perform a coupled SPR-electrochemistry experiment. Students also study the antibody-antigen binding activity. Most of the experimental work was done as a project by a grade 12 high-school student under proper supervision. We believe that the SPR device and the SPR laboratory will enhance undergraduate chemical education by introducing students to this important modern instrumentation and will help students to learn and understand the molecular interactions occurring at interfaces.

  14. Polymer-based chips for surface plasmon resonance sensors

    NASA Astrophysics Data System (ADS)

    Obreja, Paula; Cristea, Dana; Kusko, Mihai; Dinescu, Adrian

    2008-06-01

    This paper presents a design and low-cost techniques for polymer-based chips for surface plasmon resonance (SPR) sensors. To obtain a polymer chip with a prism, microchannels and a chamber at microscale dimensions, replication techniques in polymers with controlled refractive index have been developed. Photoresist, polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA) and epoxy resin were used. Silicon dioxide/silicon-based molds have been obtained by anisotropic etching of silicon, and glass prisms were used as masters for replication. The photoresist molds were obtained by optical lithography and were used to obtain the microchannels and the chamber. A liquid prepolymer (PDMS, Sylgard 184) with curing agent at a ratio of 10:1 was used, and a special technique was developed in order to fabricate the components of the structure at the same time. For the deposition and direct patterning of the metallic layers onto the polymer surface, different methods were experimented with, including sputtering. The materials and techniques used to achieve SPR sensors are presented, and the possibilities and limitations of the technology are discussed.

  15. Development of surface-plasmon-resonance-based immunoassay for cephalexin

    NASA Astrophysics Data System (ADS)

    Dillon, Paul P.; Daly, Stephen J.; Browne, Johnathan; Manning, Bernadette M.; O'Kennedy, Richard; van Amerongen, Aart

    2003-03-01

    The public concern surrounding antibiotic contamination in food and food products has made it imperative to develop analytical methods for their detection. Polyclonal antibodies and protein-hapten conjugates to cephalexin were used in the development of a surface plasmon resonance (SPR)-based inhibition immunoassay to cephalexin. A conjugate consisting of cephalexin-bovine serum albumin (BSA) was immobilised on the dextran gel surface. Dissociation between the antibody and antigen was easily achieved with 10 mmol l-1 NaOH and was very reproducible. Standards of free hapten were prepared and premixed with antibody and, after a suitable incubation time, passed over the surface of the chip with the protein-hapten conjugate immobilised. The hapten in solution inhibited the binding of antibody to the surface resulting in higher response units of antibody bound at lower concentrations of free drug. Model inhibition immunoassays to cephalexin were developed in PBS and spiked milk samples. These assays had detection ranges between 4.88 to 2,500 ng ml-1 and 244 to 3,900 ng ml-1, respectively, with reproducible results.

  16. Surface plasmon resonance microscopy: Achieving a quantitative optical response

    NASA Astrophysics Data System (ADS)

    Peterson, Alexander W.; Halter, Michael; Plant, Anne L.; Elliott, John T.

    2016-09-01

    Surface plasmon resonance (SPR) imaging allows real-time label-free imaging based on index of refraction and changes in index of refraction at an interface. Optical parameter analysis is achieved by application of the Fresnel model to SPR data typically taken by an instrument in a prism based figuration. We carry out SPR imaging on a microscope by launching light into a sample and collecting reflected light through a high numerical aperture microscope objective. The SPR microscope enables spatial resolution that approaches the diffraction limit and has a dynamic range that allows detection of subnanometer to submicrometer changes in thickness of biological material at a surface. However, unambiguous quantitative interpretation of SPR changes using the microscope system could not be achieved using the Fresnel model because of polarization dependent attenuation and optical aberration that occurs in the high numerical aperture objective. To overcome this problem, we demonstrate a model to correct for polarization diattenuation and optical aberrations in the SPR data and develop a procedure to calibrate reflectivity to index of refraction values. The calibration and correction strategy for quantitative analysis was validated by comparing the known indices of refraction of bulk materials with corrected SPR data interpreted with the Fresnel model. Subsequently, we applied our SPR microscopy method to evaluate the index of refraction for a series of polymer microspheres in aqueous media and validated the quality of the measurement with quantitative phase microscopy.

  17. Innovative antimicrobial susceptibility testing method using surface plasmon resonance.

    PubMed

    Chiang, Ya-Ling; Lin, Chi-Hung; Yen, Muh-Yong; Su, Yuan-Deng; Chen, Shean-Jen; Chen, How-Foo

    2009-03-15

    Utilizing the ultra sensitivity of surface plasmon resonance (SPR) biosensor to examine drug resistance of bacteria was studied in this research. Susceptible and resistant strains of Escherichia coli JM109 to ampicillin and those of Staphylococcus epidermidis to tetracycline, served as a blind test, were examined. The bacteria adhered on the Au thin film was treated by the injection of antibiotic flow. The optical property change of the bacteria responded to antibiotics were recorded through SPR mechanism. As a result, the susceptible strain of E. coli generally revealed more than three times of SPR angle shift when compared to the resistant one; the susceptible strain of S. epidermidis revealed irregular SPR angle shift while the resistant strain kept the SPR angle almost unchanged. The new SPR method took less than 2h of antibiotic treatment time to complete the antimicrobial susceptibility test. Different from conventional applications of SPR, specific antibodies is not required in this method. As compared to the conventional assays, Kirby-Bauer disk diffusion and variations of broth microdilution usually take 1 day to weeks to issue the report. Using this SPR assay can greatly reduce the waiting period for laboratory tests, and can therefore benefit patients who need proper antibiotic treatments to control bacterial infections. The sensitivity of the SPR biosensor built for the application is around 1.4 x 10(-4) on the refractive index.

  18. Surface plasmon resonance for detecting clenbuterol: Influence of monolayer structure

    NASA Astrophysics Data System (ADS)

    Suherman; Morita, Kinichi; Kawaguchi, Toshikazu

    2015-03-01

    Surface plasmon resonance sensor equipped with a fabricated immunosensor chip is used for detecting clenbuterol in this study. Since clenbuterol is a small analyte, indirect competitive inhibition immunoassay is employed. For fabricating the immunosurface, the Au-chip was functionalized by succinimidyl-terminated alkanethiol, and the terminal N-hydroxysuccinimide group of the self-assembled monolayer was either replaced with clenbuterol or blocked with ethanolamine. Scanning tunneling microscope experiments and electrochemical measurements depicted the domain structures of the succinimide group of succinimidyl-terminated propanethiol monolayer. The surface concentration and the orientation of succinimide group was significantly dependent on the concentration of dithiobis(succinimidyl) propionate (DSP) used in fabricating the monolayer. Furthermore, the structure of monolayer significantly influenced both the surface concentration and the orientation of clenbuterol on the sensor surface. Consequently, high coverage and standing-up configuration of clenbuterol showed high affinity for clenbuterol antibody. However, high affinity constant exhibited by the sensor surface was coupled with a low sensitivity. By contrast, lowest concentration of DSP solution (0.1 mM) used in fabricating the immunosurface showed a detection sensitivity of 3 ppt - the highest reported sensitivity for clenbuterol. For regeneration the immunosurface, 0.1 M NaOH was used and the same sensor surface could be reused for performing >100 rapid immunoreaction.

  19. Using surface plasmon resonance imaging to study bacterial biofilms.

    PubMed

    Abadian, Pegah N; Tandogan, Nil; Jamieson, John J; Goluch, Edgar D

    2014-03-01

    This paper describes the use of Surface Plasmon Resonance imaging (SPRi) as an emerging technique to study bacterial physiology in real-time without labels. The overwhelming majority of bacteria on earth exist in large multicellular communities known as biofilms. Biofilms are especially problematic because they facilitate the survival of pathogens, leading to chronic and recurring infections as well as costly industrial complications. Monitoring biofilm accumulation and removal is therefore critical in these and other applications. SPRi uniquely provides label-free, high-resolution images of biomass coverage on large channel surfaces up to 1 cm(2) in real time, which allow quantitative assessment of biofilm dynamics. The rapid imaging capabilities of this technique are particularly relevant for multicellular bacterial studies, as these cells can swim several body lengths per second and divide multiple times per hour. We present here the first application of SPRi to image Escherichia coli and Pseudomonas aeruginosa cells moving, attaching, and forming biofilms across a large surface. This is also the first time that biofilm removal has been visualized with SPRi, which has important implications for monitoring the biofouling and regeneration of fluidic systems. Initial images of the removal process show that the biofilm releases from the surface as a wave along the direction of the fluid flow.

  20. Surface plasmon resonance biosensor for enzymatic detection of small analytes

    NASA Astrophysics Data System (ADS)

    Massumi Miyazaki, Celina; Makoto Shimizu, Flávio; Mejía-Salazar, J. R.; Oliveira, Osvaldo N., Jr.; Ferreira, Marystela

    2017-04-01

    Surface plasmon resonance (SPR) biosensing is based on the detection of small changes in the refractive index on a gold surface modified with molecular recognition materials, thus being mostly limited to detecting large molecules. In this paper, we report on a SPR biosensing platform suitable to detect small molecules by making use of the mediator-type enzyme microperoxidase-11 (MP11) in layer-by-layer films. By depositing a top layer of glucose oxidase or uricase, we were able to detect glucose or uric acid with limits of detection of 3.4 and 0.27 μmol l‑1, respectively. Measurable SPR signals could be achieved because of the changes in polarizability of MP11, as it is oxidized upon interaction with the analyte. Confirmation of this hypothesis was obtained with finite difference time domain simulations, which also allowed us to discard the possible effects from film roughness changes observed in atomic force microscopy images. The main advantage of this mediator-type enzyme approach is in the simplicity of the experimental method that does not require an external potential, unlike similar approaches for SPR biosensing of small molecules. The detection limits reported here were achieved without optimizing the film architecture, and therefore the performance can in principle be further enhanced, while the proposed SPR platform may be extended to any system where hydrogen peroxide is generated in enzymatic reactions.

  1. Low Temperature Locally-Controlled Growth of Wide Bandgap Nitride and Diamond Films via Plasmon Resonance-Excited Kinetic Processes

    DTIC Science & Technology

    2015-06-18

    generation of low-temperature, electrochemical and photochemical potentials within the optical near-field of nanoscale plasmonic structures. We have...Box 12211 Research Triangle Park, NC 27709-2211 plasmonics, low-temperature, nanoscale electrochemical control REPORT DOCUMENTATION PAGE 11. SPONSOR...to employ resonant plasmonic phenomenon for the generation of low-temperature, electrochemical and photochemical potentials within the optical near

  2. Resonant terahertz absorption by plasmons in grating-gate GaN HEMT structures

    NASA Astrophysics Data System (ADS)

    Muravjov, A. V.; Veksler, D. B.; Hu, X.; Gaska, R.; Pala, N.; Saxena, H.; Peale, R. E.; Shur, M. S.

    2009-05-01

    Pronounced resonant absorption and frequency dispersion associated with an excitation of collective 2D plasmons have been observed in terahertz (0.5-4THz) transmission spectra of grating-gate 2D electron gas AlGaN/GaN HEMT (high electron mobility transistor) structures at cryogenic temperatures. The resonance frequencies correspond to plasmons with wavevectors equal to the reciprocal-lattice vectors of the metal grating, which serves both as a gate electrode for the HEMT and a coupler between plasmons and incident terahertz radiation. The resonances are tunable by changing the applied gate voltage, which controls 2D electron gas concentration in the channel. The effect can be used for resonant detection of terahertz radiation and for "on-chip" terahertz spectroscopy.

  3. Energy conversion within infrared plasmonic absorption metamaterials for multi-band resonance

    NASA Astrophysics Data System (ADS)

    Li, Yongqian; Su, Lei; Xu, Xiaolun; Zhang, Chenglin; Wang, Binbin

    2015-05-01

    The energy conversion within the cross-shaped plasmonic absorber metamaterials (PAM) was investigated theoretically and numerically in the infrared range based on the Poynting's theorem of electromagnetic energy. From the microscopic details, the heat generation owing to the electric current accounts for the majority of the energy conversion, while the magnetic resonance plays a negligible role. The PAMs possess three distinct resonant peaks standing independently, which are attributed to the polarization sensitive excitation of plasmonic resonance. Field redistribution and enhancement associated with multiplex resonant electromagnetic wave passing through the PAM medium provided insight into the energy conversion processes inside the nanostructure. The research results will assist the design of novel plasmon enhanced infrared detectors with multiple-band detection.

  4. Plasmon-Based Optical Trapping of Polymer Nano-Spheres as Explored by Confocal Fluorescence Microspectroscopy: A Possible Mechanism of a Resonant Excitation Effect

    NASA Astrophysics Data System (ADS)

    Shoji, Tatsuya; Mizumoto, Yoshihiko; Ishihara, Hajime; Kitamura, Noboru; Takase, Mai; Murakoshi, Kei; Tsuboi, Yasuyuki

    2012-09-01

    In optical trapping using photon force much enhanced by localized surface plasmon (LSP) in solution, we found that a resonant excitation effect can further enhance photon force. In this LSP-based optical trapping under a resonant excitation condition, an incident laser beam excites both LSP and electronic resonant transition of a target object simultaneously. Fluorescence microspectroscopy clearly showed that nanospheres under the resonant condition were much more efficiently trapped as compared to that under a non-resonant condition. The resonant LSP-based trapping mechanism was further reinforced by theoretical calculations taking the resonant excitation effect into account. Such resonant LSP-based trapping methodology will provide a novel approach for efficient trapping of small molecules.

  5. Tiny surface plasmon resonance sensor integrated on silicon waveguide based on vertical coupling into finite metal-insulator-metal plasmonic waveguide.

    PubMed

    Lee, Dong-Jin; Yim, Hae-Dong; Lee, Seung-Gol; O, Beom-Hoan

    2011-10-10

    We propose a tiny surface plasmon resonance (SPR) sensor integrated on a silicon waveguide based on vertical coupling into a finite thickness metal-insulator-metal (f-MIM) plasmonic waveguide structure acting as a Fabry-Perot resonator. The resonant characteristics of vertically coupled f-MIM plasmonic waveguides are theoretically investigated and optimized. Numerical results show that the SPR sensor with a footprint of ~0.0375 μm2 and a sensitivity of ~635 nm/RIU can be designed at a 1.55 μm transmission wavelength.

  6. Curvature of the localized surface plasmon resonance peak.

    PubMed

    Chen, Peng; Liedberg, Bo

    2014-08-05

    Localized surface plasmon resonance (LSPR) occurring in noble metal nanoparticles (e.g., Au) is a widely used phenomenon to report molecular interactions. Traditional LSPR sensors typically monitor shifts in the peak position or extinction in response to local refractive index changes in the close vicinity of the nanoparticle surface. The ability to resolve minute shifts/extinction changes is to a large extent limited by instrumental noise. A new strategy to evaluate LSPR responses utilizing changes in the shape of the extinction spectrum (the curvature) is proposed. The response of curvature to refractive index changes is investigated theoretically using Mie theory and an analytical expression relating the curvature to the refractive index is presented. The experimentally derived curvatures for 13 nm spherical gold nanoparticles (AuNPs) exposed to solvents with different bulk refractive indices confirm the theoretical predictions. Moreover, both the calculated and experimental findings suggest that the curvature is approximately a linear function of refractive index in regimes relevant to bio and chemical sensing. We demonstrate that curvature is superior over peak shift and extinction both in terms of signal-to-noise (S/N) ratio and reliability of LSPR sensors. With a curvature, one could readily monitor submonolayer adsorption of a low molecular weight thiol molecule (M(w) = 458.6) onto 13 nm AuNPs. It is also worthwhile mentioning that curvature is virtually insensitive to instrumental instabilities and artifacts occurring during measurement. Instabilities such as baseline tilt and shift, shift in peak position as well as sharp spikes/steps in the extinction spectra do not induce artifacts in the sensorgrams of curvature.

  7. Gold and aluminum based surface plasmon resonance biosensors: sensitivity enhancement

    NASA Astrophysics Data System (ADS)

    Biednov, Mykola; Lebyedyeva, Tetyana; Shpylovyy, Pavlo

    2015-05-01

    In this work we considered Gold and Aluminum thin films coated with additional dielectric layers as sensing platforms. Operation of these sensors is based on measuring shift in the position of the reflectivity dip in angular reflectivity spectrum of the sample. Shift can be caused by changes in the refraction index of either liquid that interacts with sensors surface (refractometric measurements) or thin adjacent biolayer on top of the sensor due to immobilization of the target molecules (biosensing). Calculations based on Fresnel equations and transfer matrix formalism allowed us to make comprehensive analysis of the angular sensitivity, shape of the reflectivity dip and dynamic range of the sensors with different dielectric coatings. Calculations were performed for both cases of bio and refractometric sensing. Results showed different dependence of the sensitivity of Au an Al based sensors upon refraction index of the dielectric coating. For Au-based surface Plasmon resonance sensor up to two times increased sensitivity can be achieved using dielectric coating with high refraction index 2.3 of proper thickness. For sensors based on aluminum we were able to achieve 50% increased angular sensitivity. At the same time width of the reflectivity dip increased proportionally to the optical thickness of the dielectric coating. For estimating sensors quality we analyzed ratio of the angular sensitivity to the width of the reflectivity dip. This ratio decreased with increase in optical thickness of the dielectric, however angular sensitivity of the sensor increased significantly. Deposition of the additional dielectric layer with high refraction index such as Niobium Oxide can also improve chemical and mechanical stability of the sensor.

  8. Nanostructured digital microfluidics for enhanced surface plasmon resonance imaging.

    PubMed

    Malic, Lidija; Veres, Teodor; Tabrizian, Maryam

    2011-01-15

    The advances in genomics and proteomics have unveiled an exhaustive catalogue of biomarkers that can potentially be used as diagnostic and prognostic indicators of genetic and infectious diseases. Current thrust in biosensor development is towards rapid, real-time, label-free and highly sensitive detection of the indicative biomarkers. While surface plasmon resonance imaging (SPRi) biosensors could potentially be the best suited candidate for biomarker-based diagnosis, important milestones need to be reached. Commercially available SPRi instrumentation is currently limited by the flow-cell technology to serial-sample processing and has limited sensitivity for the detection of markers present at low concentration. In this paper, we have implemented an approach to enhance sample handling and increase the sensitivity of the SPRi detection technique. We have developed a digital microfluidic platform with an integrated nanostructured biosensor interface that allows for rapid, ultra-low volume, sensitive, and automated on-chip SPRi detection of DNA hybridization reactions. Through the exploitation of electromagnetic properties of nanofabricated periodic gold nanoposts, SPRi signal was increased by 200% with the estimated limit of detection of 500 pM (90 attomoles). Using the versatile fluidic manipulation provided by the digital microfluidics, rapid and parallel target identification was achieved on multiple array elements within 1 min using 180 nL sample volume. By delivering multiple target analytes in individually addressable low volume droplets, without external pumps and fluidic interconnects, the overall assay time, cost and complexity was reduced. The proposed platform allows extreme versatility in the manipulation of precious low volume samples which makes this technology very suitable for diagnostic applications.

  9. Quantitative blood group typing using surface plasmon resonance.

    PubMed

    Then, Whui Lyn; Aguilar, Marie-Isabel; Garnier, Gil

    2015-11-15

    The accurate and reliable typing of blood groups is essential prior to blood transfusion. While current blood typing methods are well established, results are subjective and heavily reliant on analysis by trained personnel. Techniques for quantifying blood group antibody-antigen interactions are also very limited. Many biosensing systems rely on surface plasmon resonance (SPR) detection to quantify biomolecular interactions. While SPR has been widely used for characterizing antibody-antigen interactions, measuring antibody interactions with whole cells is significantly less common. Previous studies utilized SPR for blood group antigen detection, however, showed poor regeneration causing loss of functionality after a single use. In this study, a fully regenerable, multi-functional platform for quantitative blood group typing via SPR detection is achieved by immobilizing anti-human IgG antibody to the sensor surface, which binds to the Fc region of human IgG antibodies. The surface becomes an interchangeable platform capable of quantifying the blood group interactions between red blood cells (RBCs) and IgG antibodies. As with indirect antiglobulin tests (IAT), which use IgG antibodies for detection, IgG antibodies are initially incubated with RBCs. This facilitates binding to the immobilized monolayer and allows for quantitative blood group detection. Using the D-antigen as an example, a clear distinction between positive (>500 RU) and negative (<100 RU) RBCs is achieved using anti-D IgG. Complete regeneration of the anti-human IgG surface is also successful, showing negligible degradation of the surface after more than 100 regenerations. This novel approach is validated with human-sourced whole blood samples to demonstrate an interesting alternative for quantitative blood grouping using SPR analysis.

  10. Gold Nanoparticles with Externally Controlled, Reversible Shifts of Local Surface Plasmon Resonance Bands

    PubMed Central

    Yavuz, Mustafa S.; Jensen, Gary C.; Penaloza, David P.; Seery, Thomas A. P.; Pendergraph, Samuel A.; Rusling, James F.; Sotzing, Gregory A.

    2010-01-01

    We have achieved reversible tunability of local surface plasmon resonance in conjugated polymer functionalized gold nanoparticles. This property was facilitated by the preparation of 3,4-ethylenedioxythiophene (EDOT) containing polynorbornene brushes on gold nanoparticles via surface-initiated ring-opening metathesis polymerization. Reversible tuning of the surface plasmon band was achieved by electrochemically switching the EDOT polymer between its reduced and oxidized states. PMID:19839619

  11. Plasmonically induced transparent magnetic resonance in a metallic metamaterial composed of asymmetric double bars.

    PubMed

    Dong, Zheng-Gao; Liu, Hui; Xu, Ming-Xiang; Li, Tao; Wang, Shu-Ming; Zhu, Shi-Ning; Zhang, X

    2010-08-16

    We demonstrate that the trapped magnetic resonance mode can be induced in an asymmetric double-bar structure for electromagnetic waves normally incident onto the double-bar plane, which mode otherwise cannot be excited if the double bars are equal in length. By adjusting the structural geometry, the trapped magnetic resonance becomes transparent with little resonance absorption when it happens in the dipolar resonance regime, a phenomenon so-called plasmonic analogue of electromagnetically induced transparency (EIT). This planar EIT-like metamaterial offers a great geometry simplification by combining the radiant and subradiant resonant modes in a single double-bar resonator.

  12. Fano resonance-induced negative optical scattering force on plasmonic nanoparticles.

    PubMed

    Chen, Huajin; Liu, Shiyang; Zi, Jian; Lin, Zhifang

    2015-02-24

    We demonstrate theoretically that Fano resonance can induce a negative optical scattering force acting on plasmonic nanoparticles in the visible light spectrum when an appropriate manipulating laser beam is adopted. Under the illumination of a zeroth-order Bessel beam, the plasmonic nanoparticle at its Fano resonance exhibits a much stronger forward scattering than backward scattering and consequently leads to a net longitudinal backward optical scattering force, termed Fano resonance-induced negative optical scattering force. The extinction spectra obtained based on the Mie theory show that the Fano resonance arises from the interference of simultaneously excited multipoles, which can be either a broad electric dipole mode and a narrow electric quadrupole mode, or a quadrupole and an octupole mode mediated by the broad electric dipole. Such Fano resonance-induced negative optical scattering force is demonstrated to occur for core-shell, homogeneous, and hollow metallic particles and can therefore be expected to be universal for many other nanostructures exhibiting Fano resonance, adding considerably to the flexibility of optical micromanipulation on the plasmonic nanoparticles. More interestingly, the flexible tunability of the Fano resonance by particle morphology opens up the possibility of tailoring the optical scattering force accordingly, offering an additional degree of freedom to optical selection and sorting of plasmonic nanoparticles.

  13. Cavity enhanced ultra-thin aluminum plasmonic resonator for surface enhanced infrared absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Jiang, Xiao; Nong, Jinpeng; Chen, Na; Lan, Guilian; Tang, Linlong

    2016-11-01

    Owing to the advantages of natural abundance, low cost, and amenability to manufacturing processes, aluminum has recently been recognized as a highly promising plasmonic material that attracts extensive research interest. Here, we propose a cavity-enhanced ultra-thin plasmonic resonator for surface enhanced infrared absorption spectroscopy. The considered resonator consists of a patterned ultra-thin aluminum grating strips, a dielectric spacer layer and a reflective layer. In such structure, the resonance absorption is enhanced by the cavity formed between the patterned aluminum strips and the reflective layer. It is demonstrated that the spectral features of the resonator can be tuned by adjusting the structural parameters. Furthermore, in order to achieve a deep and broad spectral line shape, the spacer layer thickness should be properly designed to realize the simultaneous resonances for the electric and the magnetic excitations. The enhanced infrared absorption characteristics can be used for infrared sensing of the environment. When the resonator is covered with a molecular layer, the resonator can be used as a surface enhanced infrared absorption substrate to enhance the absorption signal of the molecules. A high enhanced factor of 1.15×105 can be achieved when the resonance wavelength of resonator is adjusted to match the desired vibrational mode of the molecules. Such a cavity-enhanced plasmonic resonator, which is easy for practical fabrication, is expected to have potential applications for infrared sensing with high-performance.

  14. Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmons

    NASA Astrophysics Data System (ADS)

    Liu, Peter Q.; Luxmoore, Isaac J.; Mikhailov, Sergey A.; Savostianova, Nadja A.; Valmorra, Federico; Faist, Jérôme; Nash, Geoffrey R.

    2015-11-01

    Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers capabilities of confining light in subwavelength dimensions and enhancing light-matter interactions. Recently, the technological potential of graphene-based plasmonics has been recognized as the latter features large tunability, higher field-confinement and lower loss compared with metal-based plasmonics. Here, we introduce hybrid structures comprising graphene plasmonic resonators coupled to conventional split-ring resonators, thus demonstrating a type of highly tunable metamaterial, where the interaction between the two resonances reaches the strong-coupling regime. Such hybrid metamaterials are employed as high-speed THz modulators, exhibiting ~60% transmission modulation and operating speed in excess of 40 MHz. This device concept also provides a platform for exploring cavity-enhanced light-matter interactions and optical processes in graphene plasmonic structures for applications including sensing, photo-detection and nonlinear frequency generation.

  15. Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmons.

    PubMed

    Liu, Peter Q; Luxmoore, Isaac J; Mikhailov, Sergey A; Savostianova, Nadja A; Valmorra, Federico; Faist, Jérôme; Nash, Geoffrey R

    2015-11-20

    Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers capabilities of confining light in subwavelength dimensions and enhancing light-matter interactions. Recently, the technological potential of graphene-based plasmonics has been recognized as the latter features large tunability, higher field-confinement and lower loss compared with metal-based plasmonics. Here, we introduce hybrid structures comprising graphene plasmonic resonators coupled to conventional split-ring resonators, thus demonstrating a type of highly tunable metamaterial, where the interaction between the two resonances reaches the strong-coupling regime. Such hybrid metamaterials are employed as high-speed THz modulators, exhibiting ∼60% transmission modulation and operating speed in excess of 40 MHz. This device concept also provides a platform for exploring cavity-enhanced light-matter interactions and optical processes in graphene plasmonic structures for applications including sensing, photo-detection and nonlinear frequency generation.

  16. Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmons

    PubMed Central

    Liu, Peter Q.; Luxmoore, Isaac J.; Mikhailov, Sergey A.; Savostianova, Nadja A.; Valmorra, Federico; Faist, Jérôme; Nash, Geoffrey R.

    2015-01-01

    Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers capabilities of confining light in subwavelength dimensions and enhancing light–matter interactions. Recently, the technological potential of graphene-based plasmonics has been recognized as the latter features large tunability, higher field-confinement and lower loss compared with metal-based plasmonics. Here, we introduce hybrid structures comprising graphene plasmonic resonators coupled to conventional split-ring resonators, thus demonstrating a type of highly tunable metamaterial, where the interaction between the two resonances reaches the strong-coupling regime. Such hybrid metamaterials are employed as high-speed THz modulators, exhibiting ∼60% transmission modulation and operating speed in excess of 40 MHz. This device concept also provides a platform for exploring cavity-enhanced light–matter interactions and optical processes in graphene plasmonic structures for applications including sensing, photo-detection and nonlinear frequency generation. PMID:26584781

  17. Strong Enhancement of Second Harmonic Emission by Plasmonic Resonances at the Second Harmonic Wavelength.

    PubMed

    Metzger, Bernd; Gui, Lili; Fuchs, Jaco; Floess, Dominik; Hentschel, Mario; Giessen, Harald

    2015-06-10

    We perform second harmonic spectroscopy of aluminum nanoantenna arrays that exhibit plasmonic resonances at the second harmonic wavelength between 450 and 570 nm by focusing sub-30 fs laser pulses tunable from 900 to 1140 nm onto the nanoantenna arrays. We find that a plasmonic resonance at the second harmonic wavelength boosts the overall nonlinear process by more than an order of magnitude. In particular, in the measurement the resonant second harmonic polarization component is a factor of about 70 stronger when compared to the perpendicular off-resonant second harmonic polarization. Furthermore, the maximum of the second harmonic conversion efficiency is found to be slightly blue-shifted with respect to the peak of the linear optical far-field spectrum. This fact can be understood from a simple model that accounts for the almost off-resonant absorption at the fundamental wavelength and the resonant emission process at the second harmonic.

  18. Combined surface plasmon resonance and X-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Garcia, Miguel Angel; Serrano, Aida; Rodriguez de La Fuente, Oscar; Castro, German R.

    2012-02-01

    We present a system for the excitation and measurement of surface plasmons in metallic films based on the Kretschmann-Raether configuration that can be installed in a synchrotron beamline. The device was mounted an tested in a hard X-ray Absorption beamline, BM25 Spline at ESRF. Whit this device it is possible to carry on experiments combining surface plasmon and X-ray absorption spectroscopies. The surface plasmons can be use to monitor in situ changes induced by the X-rays in the metallic films or the dielectric overlayer. Similarly, the changes in the electronic configuration of the material when surface plasmons are excited can be measured by X-ray absorption spectroscopy. The resolution of the system allows to observe changes in the signals of the order of 10-3 to 10-5 depending on the particular experiment and used configuration. The system is available for experiments at the beamline.

  19. Resonant Coupling between Molecular Vibrations and Localized Surface Plasmon Resonance of Faceted Metal Oxide Nanocrystals.

    PubMed

    Agrawal, Ankit; Singh, Ajay; Yazdi, Sadegh; Singh, Amita; Ong, Gary K; Bustillo, Karen; Johns, Robert W; Ringe, Emilie; Milliron, Delia J

    2017-04-12

    Doped metal oxides are plasmonic materials that boast both synthetic and postsynthetic spectral tunability. They have already enabled promising smart window and optoelectronic technologies and have been proposed for use in surface enhanced infrared absorption spectroscopy (SEIRA) and sensing applications. Herein, we report the first step toward realization of the former utilizing cubic F and Sn codoped In2O3 nanocrystals (NCs) to couple to the C-H vibration of surface-bound oleate ligands. Electron energy loss spectroscopy is used to map the strong near-field enhancement around these NCs that enables localized surface plasmon resonance (LSPR) coupling between adjacent nanocrystals and LSPR-molecular vibration coupling. Fourier transform infrared spectroscopy measurements and finite element simulations are applied to observe and explain the nature of the coupling phenomena, specifically addressing coupling in mesoscale assembled films. The Fano line shape signatures of LSPR-coupled molecular vibrations are rationalized with two-port temporal coupled mode theory. With this combined theoretical and experimental approach, we describe the influence of coupling strength and relative detuning between the molecular vibration and LSPR on the enhancement factor and further explain the basis of the observed Fano line shape by deconvoluting the combined response of the LSPR and molecular vibration in transmission, absorption and reflection. This study therefore illustrates various factors involved in determining the LSPR-LSPR and LSPR-molecular vibration coupling for metal oxide materials and provides a fundamental basis for the design of sensing or SEIRA substrates.

  20. Resonance self-shielding methodology in MPACT

    SciTech Connect

    Liu, Y.; Collins, B.; Kochunas, B.; Martin, W.; Kim, K. S.; Williams, M.

    2013-07-01

    The resonance self-shielding methods of the neutron transport code Michigan Parallel Characteristics based Transport (MPACT) are described in this paper. Two resonance-integral table based methods are utilized to resolve the resonance self-shielding effect. The subgroup method is a mature approach used in MPACT as the basic functionality for the resonance calculation. Another new iterative method, named the embedded self-shielding method is also implemented in MPACT. Comparisons of the two methods as well as their numerical verifications are presented. The results show that MPACT is capable of modeling the resonance self-shielding in a variety of PWR benchmarking cases, including difficult fuel lattice cases with poison, control rods or mixed gadolinia fuel rods. (authors)

  1. Localized Surface Plasmons Selectively Coupled to Resonant Light in Tubular Microcavities

    NASA Astrophysics Data System (ADS)

    Yin, Yin; Li, Shilong; Böttner, Stefan; Yuan, Feifei; Giudicatti, Silvia; Saei Ghareh Naz, Ehsan; Ma, Libo; Schmidt, Oliver G.

    2016-06-01

    Vertical gold nanogaps are created on microtubular cavities to explore the coupling between resonant light supported by the microcavities and surface plasmons localized at the nanogaps. Selective coupling of optical axial modes and localized surface plasmons critically depends on the exact location of the gold nanogap on the microcavities, which is conveniently achieved by rolling up specially designed thin dielectric films into three-dimensional microtube cavities. The coupling phenomenon is explained by a modified quasipotential model based on perturbation theory. Our work reveals the coupling of surface plasmon resonances localized at the nanoscale to optical resonances confined in microtubular cavities at the microscale, implying a promising strategy for the investigation of light-matter interactions.

  2. Using the angle-dependent resonances of molded plasmonic crystals to improve the sensitivities of biosensors.

    PubMed

    Gao, Hanwei; Yang, Jiun-Chan; Lin, Julia Y; Stuparu, Andreea D; Lee, Min Hyung; Mrksich, Milan; Odom, Teri W

    2010-07-14

    This paper describes how angle-dependent resonances from molded plasmonic crystals can be used to improve real-time biosensing. First, an inexpensive and massively parallel approach to create single-use, two-dimensional metal nanopyramidal gratings was developed. Second, although constant in bulk dielectric environments, the sensitivities (resonance wavelength shift and resonance width) of plasmonic crystals to adsorbed molecular layers of varying thickness were found to depend on incident excitation angle. Third, protein binding at dilute concentrations of protein was carried out at an angle that optimized the signal to noise of our plasmonic sensing platform. This angle-dependent sensitivity, which is intrinsic to grating-based sensors, is a critical parameter that can assist in maximizing signal to noise.

  3. DNA-probe-target interaction based detection of Brucella melitensis by using surface plasmon resonance.

    PubMed

    Sikarwar, Bhavna; Singh, Virendra V; Sharma, Pushpendra K; Kumar, Ashu; Thavaselvam, Duraipandian; Boopathi, Mannan; Singh, Beer; Jaiswal, Yogesh K

    2017-01-15

    Surface plasmon resonance (SPR) immunosensor using 4-mercaptobenzoic acid (4-MBA) modified gold (4-MBA/Au) SPR chip was developed first time for the detection of Brucella melitensis (B. melitensis) based on the screening of its complementary DNA target by using two different newly designed DNA probes of IS711 gene. Herein, interaction between DNA probes and target molecule are also investigated and result revealed that the interaction is spontaneous. The kinetics and thermodynamic results derived from the experimental data showed that the interaction between complementary DNA targets and probe 1 is more effective than that of probe 2. Equilibrium dissociation constant (KD) and maximum binding capacity of analyte (Bmax) values for the interaction of complementary DNA target with the immobilized DNA probes were calculated by using kinetic evaluation software, and found to be 15.3 pM (KD) and 81.02m° (Bmax) with probe 1 and 54.9pM and 55.29m° (Bmax), respectively. Moreover, real serum samples analysis were also carried out using immobilized probe 1 and probe 2 with SPR which showed the applicability of this methodology and provides an alternative way for the detection of B. melitensis in less than 10min. This remarkable sensing response of present methodology offer a real time and label free detection of biological warfare agent and provide an opportunity to make miniaturized sensor, indicating considerable promise for diverse environmental, bio-defence, clinical diagnostics, food safety, water and security applications.

  4. Plasmonic devices based on the dual coupled graphene-integrated ring resonators

    NASA Astrophysics Data System (ADS)

    Wang, Jicheng; Xia, Xiushan; Liang, Xiuye; Chen, Jing; Liu, Dongdong

    2015-08-01

    We have proposed a couple of plasmonic devices based on graphene sheets and ring resonators. The highly frequency-tunable multi-mode plasmonically induced transparency (PIT) device based on monolayer graphene and rings for the mid-IR region is presented in theory firstly. The multi-mode transparency windows in the spectral responses and slow light effects can be achieved in plasmonic configuration composed of two graphene resonators coupled with single-layer graphene waveguide. By varying the Fermi energy of the graphene, the multi-mode PIT resonance can be dynamic controlled without reoptimizing the geometric parameters of the structures. Based on the coupled mode theory (CMT) and Fabry-Perot (FP), we numerically investigated direct coupling and indirect coupling in the graphene-integrated PIT systems. In addition, the theoretical plasmonic devices based on graphene sheets and ring resonators are also proposed to perform as 1×2 optical spatial switch or ultra -compact Mach-Zehnder interferometer. The finite element method (FEM) is carried on to verify our designs. Those designs may pave the ways for the further development of the compact high-performance plasmonic communication devices.

  5. Fano coil-type resonances: a plasmonic tool for magnetic field enhancement (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Panaro, Simone; Proietti Zaccaria, Remo; Toma, Andrea

    2016-09-01

    Spintronics and spin-based technology rely on the ultra-fast unbalance of the electronic spin population in quite localized spatial regions. However, as a matter of fact, the low susceptibility of conventional materials at high frequencies strongly limits these phenomena, rendering the efficiency of magnetically active devices insufficient for application purposes. Among the possible strategies which can be envisaged, plasmonics offers a direct approach to increase the effect of local electronic unbalancing processes. By confining and enhancing free radiation in nm-size spatial regions, plasmonic nano-assemblies have demonstrated to support very intense electric and magnetic hot-spots. In particular, very recent studies have proven the fine control of magnetic fields in Fano resonance condition. The near-field-induced out-of-phase oscillation of localized surface plasmons has manifested itself with the arising of magnetic sub-diffractive hot-spots. Here, we show how this effect can be further boosted in the mid-infrared regime via the introduction of higher order plasmonic modes. The investigated system, namely Moon Trimer Resonator, combines the high efficiency of a strongly coupled nano-assembly in Fano interferential condition with the elevated tunability of the quadrupolar resonance supported by a moon-like geometry. The fine control of the apical gap in this unique nanostructure, characterizes a plasmonic device able to tune its resonance without any consequence on the magnetic hot-spot size, thus enabling an efficient squeezing in the infrared.

  6. Near-field coupling and resonant cavity modes in plasmonic nanorod metamaterials.

    PubMed

    Song, Haojie; Zhang, Junxi; Fei, Guangtao; Wang, Junfeng; Jiang, Kang; Wang, Pei; Lu, Yonghua; Iorsh, Ivan; Xu, Wei; Jia, Junhui; Zhang, Lide; Kivshar, Yuri S; Zhang, Lin

    2016-10-14

    Plasmonic resonant cavities are capable of confining light at the nanoscale, resulting in both enhanced local electromagnetic fields and lower mode volumes. However, conventional plasmonic resonant cavities possess large Ohmic losses at metal-dielectric interfaces. Plasmonic near-field coupling plays a key role in a design of photonic components based on the resonant cavities because of the possibility to reduce losses. Here, we study the plasmonic near-field coupling in the silver nanorod metamaterials treated as resonant nanostructured optical cavities. Reflectance measurements reveal the existence of multiple resonance modes of the nanorod metamaterials, which is consistent with our theoretical analysis. Furthermore, our numerical simulations show that the electric field at the longitudinal resonances forms standing waves in the nanocavities due to the near-field coupling between the adjacent nanorods, and a new hybrid mode emerges due to a coupling between nanorods and a gold-film substrate. We demonstrate that this coupling can be controlled by changing the gap between the silver nanorod array and gold substrate.

  7. Near-field coupling and resonant cavity modes in plasmonic nanorod metamaterials

    NASA Astrophysics Data System (ADS)

    Song, Haojie; Zhang, Junxi; Fei, Guangtao; Wang, Junfeng; Jiang, Kang; Wang, Pei; Lu, Yonghua; Iorsh, Ivan; Xu, Wei; Jia, Junhui; Zhang, Lide; Kivshar, Yuri S.; Zhang, Lin

    2016-10-01

    Plasmonic resonant cavities are capable of confining light at the nanoscale, resulting in both enhanced local electromagnetic fields and lower mode volumes. However, conventional plasmonic resonant cavities possess large Ohmic losses at metal-dielectric interfaces. Plasmonic near-field coupling plays a key role in a design of photonic components based on the resonant cavities because of the possibility to reduce losses. Here, we study the plasmonic near-field coupling in the silver nanorod metamaterials treated as resonant nanostructured optical cavities. Reflectance measurements reveal the existence of multiple resonance modes of the nanorod metamaterials, which is consistent with our theoretical analysis. Furthermore, our numerical simulations show that the electric field at the longitudinal resonances forms standing waves in the nanocavities due to the near-field coupling between the adjacent nanorods, and a new hybrid mode emerges due to a coupling between nanorods and a gold-film substrate. We demonstrate that this coupling can be controlled by changing the gap between the silver nanorod array and gold substrate.

  8. Phase effects in guided mode resonances II: measuring the angular phase of a surface plasmon polariton

    NASA Astrophysics Data System (ADS)

    Theisen, M. J.; Brown, T. G.

    2015-02-01

    We show how the phase of a resonant interaction between a focused beam and a guided mode can be directly observed in a pupil imaging experiment, in which the irradiance leaving the pupil of a standard microscope is relayed to an image sensor through a combination Wollaston prism, calcite beam splitter and polarizer. We apply the method to the observation of a surface plasmon polariton resonance excited in a corrugated silver film fabricated using electron beam lithography. We discuss how this particular imaging configuration could be adapted for applications in plasmonic optical sensing.

  9. Brightening Gold Nanoparticles: New Sensing Approach Based on Plasmon Resonance Energy Transfer

    PubMed Central

    Shi, Lei; Jing, Chao; Gu, Zhen; Long, Yi-Tao

    2015-01-01

    Scattering recovered plasmonic resonance energy transfer (SR-PRET) was reported by blocking the plasmon resonance energy transfer (PRET) from gold nanoparticle (GNP) to the adsorbed molecules (RdBS). Due to the selective cleavage of the Si-O bond by F− ions, the quenching is switched off causing an increase in the brightness of the GNPs,detected using dark-field microscopy (DFM) were brightened. This method was successfully applied to the determination of fluoride ions in water. The SR-PRET provides a potential approach for a vitro/vivo sensing with high sensitivity and selectivity. PMID:25959016

  10. Optical bistability effect in plasmonic racetrack resonator with high extinction ratio.

    PubMed

    Wang, Xiaolei; Jiang, Houqiang; Chen, Junxue; Wang, Pei; Lu, Yonghua; Ming, Hai

    2011-09-26

    In this paper, optical bistability effect in an ultracompact plasmonic racetrack resonator with nonlinear optical Kerr medium is investigated both analytically and numerically. The properties of optical bistability and pump threshold are studied at 1.55 µm with various detuning parameters by an analytical model. The transmission switch from the upper branch to the lower branch with a pulse is also demonstrated by a finite-difference time-domain method. An extinction ratio of 97.8% and a switching time of 0.38 ps can be achieved with proper detuning parameter. Such a plasmonic resonator design provides a promising realization for highly effective optical modulators and switch.

  11. Plasmonic resonance scattering from silver nanowire illuminated by tightly focused singular beam.

    PubMed

    Normatov, Alexander; Spektor, Boris; Leviatan, Yehuda; Shamir, Joseph

    2010-08-15

    We investigate scattering features of tightly focused singular beams by placing a cylindrical nanowire in the vicinity of a line phase singularity. Applying an illumination wavelength corresponding to silver cylinder plasmonic resonance, we compare the scattering response with that of a perfect conductor. The rigorous modeling employs a 2D version of the Richards-Wolf focusing method and the source model technique. It is found that a cylinder with a plasmonic resonance produces a strong scattering response by deflecting the power flow toward the optical singularity region, where otherwise the power approaches zero.

  12. Electromagnetic wave band structure due to surface plasmon resonances in a complex plasma

    NASA Astrophysics Data System (ADS)

    Vladimirov, S. V.; Ishihara, O.

    2016-07-01

    The dielectric properties of complex plasma containing either metal or dielectric spherical inclusions (macroparticles, dust) are investigated. We focus on surface plasmon resonances on the macroparticle surfaces and their effect on electromagnetic wave propagation. It is demonstrated that the presence of surface plasmon oscillations can significantly modify plasma electromagnetic properties by resonances and cutoffs in the effective permittivity. This leads to related branches of electromagnetic waves and to the wave band gaps. The conditions necessary to observe the band-gap structure in laboratory dusty plasma and/or space (cosmic) dusty plasmas are discussed.

  13. A single particle plasmon resonance study of 3D conical nanoantennas.

    PubMed

    Schäfer, Christian; Gollmer, Dominik A; Horrer, Andreas; Fulmes, Julia; Weber-Bargioni, Alexander; Cabrini, Stefano; Schuck, P James; Kern, Dieter P; Fleischer, Monika

    2013-09-07

    Metallic nanocones are well-suited optical antennas for near-field microscopy and spectroscopy, exhibiting a number of different plasmonic modes. A major challenge in using nanocones for many applications is maximizing the signal at the tip while minimizing the background from the base. It is shown that nanocone plasmon resonance properties can be shifted over a wide range of wavelengths by variation of the substrate, material, size and shape, enabling potential control over specific modes and field distributions. The individual resonances are identified and studied by correlated single particle dark field scattering and scanning electron microscopy in combination with numerical simulations.

  14. Enhanced sensitivity of surface plasmon resonance phase-interrogation biosensor by using oblique deposited silver nanorods

    NASA Astrophysics Data System (ADS)

    Chung, Hung-Yi; Chen, Chih-Chia; Wu, Pin Chieh; Tseng, Ming Lun; Lin, Wen-Chi; Chen, Chih-Wei; Chiang, Hai-Pang

    2014-09-01

    Sensitivity of surface plasmon resonance phase-interrogation biosensor is demonstrated to be enhanced by oblique deposited silver nanorods. Silver nanorods are thermally deposited on silver nanothin film by oblique angle deposition (OAD). The length of the nanorods can be tuned by controlling the deposition parameters of thermal deposition. By measuring the phase difference between the p and s waves of surface plasmon resonance heterodyne interferometer with different wavelength of incident light, we have demonstrated that maximum sensitivity of glucose detection down to 7.1 × 10-8 refractive index units could be achieved with optimal deposition parameters of silver nanorods.

  15. Enhanced sensitivity of surface plasmon resonance phase-interrogation biosensor by using oblique deposited silver nanorods.

    PubMed

    Chung, Hung-Yi; Chen, Chih-Chia; Wu, Pin Chieh; Tseng, Ming Lun; Lin, Wen-Chi; Chen, Chih-Wei; Chiang, Hai-Pang

    2014-01-01

    Sensitivity of surface plasmon resonance phase-interrogation biosensor is demonstrated to be enhanced by oblique deposited silver nanorods. Silver nanorods are thermally deposited on silver nanothin film by oblique angle deposition (OAD). The length of the nanorods can be tuned by controlling the deposition parameters of thermal deposition. By measuring the phase difference between the p and s waves of surface plasmon resonance heterodyne interferometer with different wavelength of incident light, we have demonstrated that maximum sensitivity of glucose detection down to 7.1 × 10(-8) refractive index units could be achieved with optimal deposition parameters of silver nanorods.

  16. Tunable and angle-insensitive plasmon resonances in graphene ribbon arrays with multispectral diffraction response

    SciTech Connect

    Li, Kangwen; Ma, Xunpeng; Zhang, Zuyin; Xu, Yun Song, Guofeng

    2014-03-14

    Plasmon resonances in graphene ribbon arrays are investigated numerically by means of the Finite Element Method. Numerical analysis shows that a series of multipolar resonances take place when graphene ribbon arrays are illuminated by a TM polarized electromagnetic wave. Moreover, these resonances are angle-independent, and can be tuned greatly by the width and the doping level of the graphene ribbons. Specifically, we demonstrate that for graphene arrays with several sets of graphene ribbons, which have different widths or doping levels, each of these multipolar resonances will be split into several ones. In addition, as plasmon resonances can confine electromagnetic field at the ribbon edges, graphene ribbons with different widths or doping levels offer intriguing application for electrically tunable spectral imaging.

  17. Dielectric tuned surface plasmon resonances on metallic gratings

    NASA Astrophysics Data System (ADS)

    Hauser, Adam; Flaherty, Bill; Law, Ka Ming; Mikheev, Evgeny; Kajdos, Adam; Stemmer, Susanne; Allen, S. James

    2015-03-01

    We explore the effect of substrate dielectric constant on the dispersion of infrared surface plasmons supported by micron scale metal gratings. Of particular interest are substrate dielectrics that can be tuned by electric fields and thereby make possible gated plasmonic devices. Angle resolved s and p polarized reflectivity is used to observe the plasmon dispersion for Pt gratings on various oxide dielectrics and heterostructures, LSAT, SrTiO3, Nb:SrTiO3 and LSAT/SrTiO3/GdTiO3. Most striking is the shift in the plasmon dispersion upon Nb doping of SrTiO3 caused by the free carrier contribution to the dielectric constant. We focus our attention on a metal-oxide-metal heterostructure, Pt/BaxSr1-xTiO3/Pt-grating that serves to confine the infrared field to the electric field modulated region enhancing the potential for a gated plasmonic structure. Supported by the ONR MURI ``Extreme electron density electronics'' N00014-12-0976.

  18. Multipitched Diffraction Gratings for Surface Plasmon Resonance-Enhanced Infrared Reflection Absorption Spectroscopy.

    PubMed

    Petefish, Joseph W; Hillier, Andrew C

    2015-11-03

    We demonstrate the application of metal-coated diffraction gratings possessing multiple simultaneous pitch values for surface enhanced infrared absorption (SEIRA) spectroscopy. SEIRA increases the magnitude of vibrational signals in infrared measurements by one of several mechanisms, most frequently involving the enhanced electric field associated with surface plasmon resonance (SPR). While the majority of SEIRA applications to date have employed nanoparticle-based plasmonic systems, recent advances have shown how various metals and structures lead to similar signal enhancement. Recently, diffraction grating couplers have been demonstrated as a highly tunable platform for SEIRA. Indeed, gratings are an experimentally advantageous platform due to the inherently tunable nature of surface plasmon excitation at these surfaces since both the grating pitch and incident angle can be used to modify the spectral location of the plasmon resonance. In this work, we use laser interference lithography (LIL) to fabricate gratings possessing multiple pitch values by subjecting photoresist-coated glass slides to repetitive exposures at varying orientations. After metal coating, these gratings produced multiple, simultaneous plasmon peaks associated with the multipitched surface, as identified by infrared reflectance measurements. These plasmon peaks could then be coupled to vibrational modes in thin films to provide localized enhancement of infrared signals. We demonstrate the flexibility and tunability of this platform for signal enhancement. It is anticipated that, with further refinement, this approach might be used as a general platform for broadband enhancement of infrared spectroscopy.

  19. Imaging of polarization rotation in transmission resonances of periodic plasmonic structures

    NASA Astrophysics Data System (ADS)

    Arora, Pankaj; Krishnan, Ananth

    2014-05-01

    We imaged polarization rotation of transmitted light in 1D Periodic Plasmonic Structures (PPS) fabricated on thin metal coated dielectric substrate. Several PPS of 50% duty cycle and extremely low aspect ratio (height to width ratio) of 0.1 were designed using rigorous coupled wave analysis to exhibit transmission plasmonic resonances at optical wavelengths (400 nm to 700 nm). PPS were fabricated using electron beam lithography, evaporation and lift-off process on glass substrates coated with thin metal. The PPS were characterized using normally incident broadband visible light and crossaxis Polarizer Analyzer setup, with the transmitted light imaged in direct and momentum space using a camera. When the cross axis Polarizer Analyzer were positioned at +45° & -45° respectively w.r.t. plane of incidence, bright emissions of Green, Yellow or Red colors corresponding to transmission plasmonic resonances of the PPS with different periods, were observed in both direct and Fourier planes, instead of completely dark images. From the measured emission momentum in Fourier plane images and spectra of collected light, the emissions were attributed to the excitations of surface plasmons and the reason for surface plasmon excitation in this arrangement is strong coupling of hybrid modes with each other caused by the anisotropy introduced by grating which strongly enhances the efficiency of Polarization rotation. The presented structures behave as frequency selective half wave plates in transmission configuration and could also be used to eliminate the effect of direct beam while imaging the coupling to surface plasmons in periodic structures.

  20. Surface plasmon resonance measurements of plasma antibody avidity during primary and secondary responses to anthrax protective antigen.

    PubMed

    Lynch, Heather E; Stewart, Shelley M; Kepler, Thomas B; Sempowski, Gregory D; Alam, S Munir

    2014-02-01

    Establishment of humoral immunity against pathogens is dependent on events that occur in the germinal center and the subsequent induction of high-affinity neutralizing antibodies. Quantitative assays that allow monitoring of affinity maturation and duration of antibody responses can provide useful information regarding the efficacy of vaccines and adjuvants. Using an anthrax protective antigen (rPA) and alum model antigen/adjuvant system, we describe a methodology for monitoring antigen-specific serum antibody concentration and avidity by surface plasmon resonance during primary and secondary immune responses. Our analyses showed that following a priming dose in mice, rPA-specific antibody concentration and avidity increases over time and reaches a maximal response in about six weeks, but gradually declines in the absence of antigenic boost. Germinal center reactions were observed early with maximal development achieved during the primary response, which coincided with peak antibody avidity responses to primary immunization. Boosting with antigen resulted in a rapid increase in rPA-specific antibody concentration and five-fold increase in avidity, which was not dependent on sustained GC development. The described methodology couples surface plasmon resonance-based plasma avidity measurements with germinal center analysis and provides a novel way to monitor humoral responses that can play a role in facilitating vaccine and adjuvant development.

  1. Mining the salivary proteome with grating-coupled surface plasmon resonance imaging and surface plasmon coupled emission microarrays.

    PubMed

    Molony, Ryan D; Rice, James M; Yuk, Jong Seol; Shetty, Vivek; Dey, Dipak; Lawrence, David A; Lynes, Michael A

    2012-08-01

    Biological indicators have numerous and widespread utility in personalized medicine, but the measurement of these indicators also poses many technological and practical challenges. Blood/plasma has typically been used as the sample source with which to measure these indicators, but the invasiveness associated with sample procurement has led to increased interest in saliva as an attractive alternative. However, there are unique issues associated with the measurement of saliva biomarkers. These issues are compounded by the imperfect correlation between saliva and plasma with respect to biomarker profiles. In this manuscript, we address the technical challenges associated with saliva biomarker quantification. We describe a high-content microarray assay that employs both grating-coupled surface plasmon resonance imaging and surface plasmon-coupled emission modalities in a highly sensitive assay with a large dynamic range. This powerful approach provides the tools to map the proteome of saliva, which in turn should greatly enhance the utility of salivary biomarker profiles in personalized medicine.

  2. Plasmonic resonances in ordered and disordered aluminum nanocavities arrays.

    NASA Astrophysics Data System (ADS)

    Campuzano, R. G.; Mendoza, D.

    2017-01-01

    Nanocavities arrays were synthesized by electrochemical anodization of aluminum using oxalic and phosphoric acids as electrolytes. The morphology and topography of these structures were evaluated by SEM and AFM. Plasmonic properties of Al cavities arrays with different ordering and dimensions were analysed based on specular reflectivity. Al cavities arrays fabricated with phosphoric acid dramatically reduced the optical reflectivity as compared with unstructured Al. At the same time pronounced reflectivity dips were detectable in the 300nm-400nm range, which were ascribed to (0,1) plasmonic mode, and also a colored appearance in the samples is noticeably depending on the observation angle. These changes are not observed in samples made with oxalic acid and this fact was explained, based on a theoretical model, in terms that the surface plasmons are excited far in the UV range.

  3. Radiation-Suppressed plasmonic open resonators designed by nonmagnetic transformation optics

    PubMed Central

    Xu, Hongyi; Wang, Xingjue; Yu, Tianyuan; Sun, Handong; Zhang, Baile

    2012-01-01

    How to confine light energy associated with surface plasmon polaritons (SPPs) in a physical space with minimal radiation loss whereas creating maximum interacting section with surrounding environment is of particular interest in plasmonic optics. By virtue of transformation optics, we propose a design method of forming a polygonal surface-plasmonic resonator in fully open structures by applying the nonmagnetic affine transformation optics strategy. The radiation loss can be suppressed because SPPs that propagate in the designed open structures will be deceived as if they were propagating on a flat metal/dielectric interface without radiation. Because of the nonmagnetic nature of the transformation strategy, this design can be implemented with dielectric materials available in nature. An experimentally verifiable model is subsequently proposed for future experimental demonstration. Our design may find potential applications in omnidirectional sensing, light harvesting, energy storage and plasmonic lasing. PMID:23136641

  4. Plasmon resonant gold-coated liposomes for spectrally coded content release

    NASA Astrophysics Data System (ADS)

    Leung, Sarah J.; Troutman, Timothy S.; Romanowski, Marek

    2009-02-01

    We have recently introduced liposome-supported plasmon resonant gold nanoshells (Troutman et al., Adv. Mater. 2008, 20, 2604-2608). These plasmon resonant gold-coated liposomes are degradable into components of a size compatible with renal clearance, potentially enabling their use as multifunctional agents in applications in nanomedicine, including imaging, diagnostics, therapy, and drug delivery. The present research demonstrates that laser illumination at the wavelength matching the plasmon resonance band of a gold-coated liposome leads to the rapid release of encapsulated substances, which can include therapeutic and diagnostic agents. Leakage of encapsulated contents is monitored through the release of self-quenched fluorescein, which provides an increase in fluorescence emission upon release. Moreover, the resonant peak of these gold-coated liposomes is spectrally tunable in the near infrared range by varying the concentration of gold deposited on the surface of liposomes. Varying the plasmon resonant wavelengths of gold-coated liposomes can provide a method for spectrally-coding their light-mediated content release, so that the release event is initiated by the specific wavelength of light used to illuminate the liposomes. The development of spectrally-coded release can find applications in controlled delivery of multiple agents to support complex diagnostic tests and therapeutic interventions.

  5. Plasmon resonant gold-coated liposomes for spectrally coded content release.

    PubMed

    Leung, Sarah J; Troutman, Timothy S; Romanowski, Marek

    2009-02-01

    We have recently introduced liposome-supported plasmon resonant gold nanoshells (Troutman et al., Adv. Mater. 2008, 20, 2604-2608). These plasmon resonant gold-coated liposomes are degradable into components of a size compatible with renal clearance, potentially enabling their use as multifunctional agents in applications in nanomedicine, including imaging, diagnostics, therapy, and drug delivery. The present research demonstrates that laser illumination at the wavelength matching the plasmon resonance band of a gold-coated liposome leads to the rapid release of encapsulated substances, which can include therapeutic and diagnostic agents. Leakage of encapsulated contents is monitored through the release of self-quenched fluorescein, which provides an increase in fluorescence emission upon release. Moreover, the resonant peak of these gold-coated liposomes is spectrally tunable in the near infrared range by varying the concentration of gold deposited on the surface of liposomes. Varying the plasmon resonant wavelengths of gold-coated liposomes can provide a method for spectrally-coding their light-mediated content release, so that the release event is initiated by the specific wavelength of light used to illuminate the liposomes. The development of spectrally-coded release can find applications in controlled delivery of multiple agents to support complex diagnostic tests and therapeutic interventions.

  6. Strong Light Confinement in Metal-Coated Si Nanopillars: Interplay of Plasmonic Effects and Geometric Resonance.

    PubMed

    Kim, Sujung; Kim, Eunah; Lee, Yeon Ui; Ko, Eunkyo; Park, Hyeong-Ho; Wu, Jeong Weon; Kim, Dong-Wook

    2017-12-01

    We investigated the influence of metal coating on the optical characteristics of Si nanopillar (NP) arrays with and without thin metal layers coated on the sample surface. The reflection dips of the metal-coated arrays were much broader and more pronounced than those of the bare arrays. The coated metal layers consisted of two parts-the metal disks on the Si NP top and the holey metal backreflectors on the Si substrate. The Mie-like geometrical resonance in the NPs, the localized surface plasmons in the metal disks, and the propagation of surface plasmon polariton along the backreflector/substrate interface could contribute to the reflection spectra. Finite-difference time-domain simulation results showed that the interplay of the plasmonic effects and the geometric resonance gave rise to significantly enhanced light confinement and consequent local absorption in the metal-Si hybrid nanostructures.

  7. Broadband light trapping in thin organic photovoltaic cells using plasmonic resonant antennas

    NASA Astrophysics Data System (ADS)

    Le, Khai Q.

    2013-08-01

    A numerical investigation of plasmonic resonant antennas influence on optical absorption efficiency of organic photovoltaic (PV) cells with thin active layers is reported. Integrating cylindrical Ag antennas on PV cells can enhance absorption efficiency by up to 22%, over a broad bandwidth of operation. This corresponds to an increase in integrated AM1.5G absorption at normal incidence from 48 to 58.5%. Broadband enhancement is observed for transverse-electric and transverse-magnetic polarized incident light, over a wide angle range. It is attributed to plasmonic antennas converting incident sunlight to surface plasmon resonant modes, localized around the antenna/polymer active layer interface. This results in a strong field enhancement in the active layer and enhances absorption efficiency.

  8. Optical magnetism and plasmonic Fano resonances in metal-insulator-metal oligomers.

    PubMed

    Verre, R; Yang, Z J; Shegai, T; Käll, M

    2015-03-11

    The possibility of achieving optical magnetism at visible frequencies using plasmonic nanostructures has recently been a subject of great interest. The concept is based on designing structures that support plasmon modes with electron oscillation patterns that imitate current loops, that is, magnetic dipoles. However, the magnetic resonances are typically spectrally narrow, thereby limiting their applicability in, for example, metamaterial designs. We show that a significantly broader magnetic response can be realized in plasmonic pentamers constructed from metal-insulator-metal (MIM) sandwich particles. Each MIM unit acts as a magnetic meta-atom and the optical magnetism is rendered quasi-broadband through hybridization of the in-plane modes. We demonstrate that scattering spectra of individual MIM pentamers exhibit multiple Fano resonances and a broad subradiant spectral window that signals the magnetic interaction and a hierarchy of coupling effects in these intricate three-dimensional nanoparticle oligomers.

  9. Strong Light Confinement in Metal-Coated Si Nanopillars: Interplay of Plasmonic Effects and Geometric Resonance

    NASA Astrophysics Data System (ADS)

    Kim, Sujung; Kim, Eunah; Lee, Yeon Ui; Ko, Eunkyo; Park, Hyeong-Ho; Wu, Jeong Weon; Kim, Dong-Wook

    2017-02-01

    We investigated the influence of metal coating on the optical characteristics of Si nanopillar (NP) arrays with and without thin metal layers coated on the sample surface. The reflection dips of the metal-coated arrays were much broader and more pronounced than those of the bare arrays. The coated metal layers consisted of two parts—the metal disks on the Si NP top and the holey metal backreflectors on the Si substrate. The Mie-like geometrical resonance in the NPs, the localized surface plasmons in the metal disks, and the propagation of surface plasmon polariton along the backreflector/substrate interface could contribute to the reflection spectra. Finite-difference time-domain simulation results showed that the interplay of the plasmonic effects and the geometric resonance gave rise to significantly enhanced light confinement and consequent local absorption in the metal-Si hybrid nanostructures.

  10. Plasmon-Induced Resonant Energy Transfer: a coherent dipole-dipole coupling mechanism

    NASA Astrophysics Data System (ADS)

    Bristow, Alan D.; Cushing, Scott K.; Li, Jiangtian; Wu, Nianqiang

    Metal-insulator-semiconductor core-shell nanoparticles have been used to demonstrate a dipole-dipole coupling mechanism that is entirely dependent on the dephasing time of the localized plasmonic resonance. Consequently, the short-time scale of the plasmons leads to broad energy uncertainty that allows for excitation of charge carriers in the semiconductor via stimulation of photons with energies below the energy band gap. In addition, this coherent energy transfer process overcomes interfacial losses often associated with direct charge transfer. This work explores the efficiency of the energy transfer process, the dipole-dipole coupling strength with dipole separation, shell thickness and plasmonic resonance overlap. We demonstrate limits where the coherent nature of the coupling is switched off and charge transfer processes can dominate. Experiments are performed using transient absorption spectroscopy. Results are compared to calculations using a quantum master equation. These nanostructures show strong potential for improving solar light-harvesting for power and fuel generation.

  11. Effect of optical sensitisation on a surface plasmon resonance

    SciTech Connect

    Vinogradov, S V; Kononov, M A; Savranskii, V V; Valyanskii, S I; Urbaitis, M F

    2003-08-31

    A change in the excitation angle of surface plasmons is found in a three-layer thin-film Ag - Al{sub 2}O{sub 3} - AgI structure upon its optical sensitisation with the Arsenazo III dye [2,7-Bis(2-arsonophenylazo)chromotropic acid Disodium salt]. (special issue devoted to the memory of academician a m prokhorov)

  12. Tri-layered composite plasmonic structure with a nanohole array for multiband enhanced absorption at visible to NIR frequencies: plasmonic and metamaterial resonances

    NASA Astrophysics Data System (ADS)

    Behera, Gangadhar; Ramakrishna, S. Anantha

    2016-02-01

    A tri-layered composite structure of gold/ZnS/gold, with the top gold layer patterned into a periodic array of circular holes, was fabricated by laser interference lithography and lift-off processes. This plasmonic composite absorbing structure showed a series of enhanced absorption peaks across the visible to NIR frequencies with an peak absorption exceeding 95% at 0.52 μm wavelength. These absorption peaks were reproduced in electromagnetic simulations of the structures. The peaks are shown to arise from the various resonances of the system: the localized surface plasmon resonances of the holes, the surface plasmon polaritons on the various interfaces and the shape dependent electromagnetic resonances of the holes. The measured angular dispersion of the absorption peaks indicated the SPP origin of the resonances while the computer simulations of the electromagnetic fields could be used to understand the nature of the localized resonances.

  13. Engineered absorption enhancement and induced transparency in coupled molecular and plasmonic resonator systems.

    PubMed

    Adato, Ronen; Artar, Alp; Erramilli, Shyamsunder; Altug, Hatice

    2013-06-12

    Coupled plasmonic resonators have become the subject of significant research interest in recent years as they provide a route to dramatically enhanced light-matter interactions. Often, the design of these coupled mode systems draws intuition and inspiration from analogies to atomic and molecular physics systems. In particular, they have been shown to mimic quantum interference effects, such as electromagnetically induced transparency (EIT) and Fano resonances. This analogy also been used to describe the surface-enhanced absorption effect where a plasmonic resonance is coupled to a weak molecular resonance. These important phenomena are typically described using simple driven harmonic (or linear) oscillators (i.e., mass-on-a-spring) coupled to each other. In this work, we demonstrate the importance of an essential interdependence between the rate at which the system can be driven by an external field and its damping rate through radiative loss. This link is required in systems exhibiting time-reversal symmetry and energy conservation. Not only does it ensure an accurate and physically consistent description of resonant systems but leads directly to interesting new effects. Significantly, we demonstrate this dependence to predict a transition between EIT and electromagnetically induced absorption that is solely a function of the ratio of the radiative to intrinsic loss rates in coupled resonator systems. Leveraging the temporal coupled mode theory, we introduce a unique and intuitive picture that accurately describes these effects in coupled plasmonic/molecular and fully plasmonic systems. We demonstrate our approach's key features and advantages analytically as well as experimentally through surface-enhanced absorption spectroscopy and plasmonic metamaterial applications.

  14. Near-Field Spectroscopy and Imaging of Subwavelength Plasmonic Terahertz Resonators

    DOE PAGES

    Mitrofanov, Oleg; Khromova, Irina; Siday, Thomas; ...

    2016-04-22

    We describe the temporal evolution of the terahertz (THz) field leading to the excitation of plasmonic resonances in carbon microfibers. The field evolution is mapped in space and time for the 3/2 wavelength resonance using a subwavelength aperture THz near-field probe with an embedded THz photoconductive detector. The excitation of surface waves at the fiber tips leads to the formation of a standing wave along the fiber. Local THz time-domain spectroscopy at one of the standing wave crests shows a clear third-order resonance peak at 1.65 THz, well described by the Lorentz model. Lastly, this application of the subwavelength aperturemore » THz near-field microscopy for mode mapping and local spectroscopy demonstrates the potential of near-field methods for studies of subwavelength plasmonic THz resonators.« less

  15. Near-Field Spectroscopy and Imaging of Subwavelength Plasmonic Terahertz Resonators

    SciTech Connect

    Mitrofanov, Oleg; Khromova, Irina; Siday, Thomas; Thompson, Robert J.; Ponomarev, Andrey N.; Brener, Igal; Reno, John L.

    2016-04-22

    We describe the temporal evolution of the terahertz (THz) field leading to the excitation of plasmonic resonances in carbon microfibers. The field evolution is mapped in space and time for the 3/2 wavelength resonance using a subwavelength aperture THz near-field probe with an embedded THz photoconductive detector. The excitation of surface waves at the fiber tips leads to the formation of a standing wave along the fiber. Local THz time-domain spectroscopy at one of the standing wave crests shows a clear third-order resonance peak at 1.65 THz, well described by the Lorentz model. Lastly, this application of the subwavelength aperture THz near-field microscopy for mode mapping and local spectroscopy demonstrates the potential of near-field methods for studies of subwavelength plasmonic THz resonators.

  16. A reconfigurable subwavelength plasmonic fano nano-antenna based on split ring resonator

    NASA Astrophysics Data System (ADS)

    Hosseinbeig, Ahmad; Pirooj, Azadeh; Zarrabi, Ferdows B.

    2017-02-01

    In this article, a reconfigurable subwavelength plasmonic nano-antenna with Fano resonance effect is presented based on the dual ring structure. In order to achieve reconfigurable characteristics, the interaction of gold with graphene is studied. SiN substrate with refractive index of 1.98 and gold with Palik optical characteristic modified for metal layer are utilized in the design of the proposed nano-antenna. Simulations are performed by using CST Microwave Studio. The biasing effect on extinction cross section is studied for 0 to 0.8 eV. It is shown that the gap method is useful for exciting the Fano resonance in the dual ring nano-antenna and there is only a plasmonic resonance in the simple dual ring antenna. The proposed nano-antenna is useful for THz medical spectroscopy due to its simple design and the ability to control the second resonance frequency by changing the bias of the graphene.

  17. Matching plasmon resonances to the C=C and C-H bonds in estradiol

    NASA Astrophysics Data System (ADS)

    Mbomson, Ifeoma G.; McMeekin, Scott; De La Rue, Richard; Johnson, Nigel P.

    2015-03-01

    We tune nanoantennas to resonate within mid-infrared wavelengths to match the vibrational resonances of C=C and C-H of the hormone estradiol. Modelling and fabrication of the nanoantennas produce plasmon resonances between 2 μm to 7 μm. The hormone estradiol was dissolved in ethanol and evaporated, leaving thickness of a few hundreds of nanometres on top of gold asymmetric split H-like shaped on a fused silica substrate. The reflectance was measured and a red-shift is recorded from the resonators plasmonic peaks. Fourier transform infrared spectroscopy is use to observe enhanced spectra of the stretching modes for the analyte which belongs to alkenyl biochemical group.

  18. D-shape polymer optical fibres for surface plasmon resonance sensing

    NASA Astrophysics Data System (ADS)

    Gasior, K.; Martynkien, T.; Wojcik, G.; Mergo, P.; Urbanczyk, W.

    2016-12-01

    We experimentally studied three different D-shape polymer optical fibres with an exposed core for their applications as surface plasmon resonance sensors. The first one was a conventional D-shape fibre with no microstructure while in two others the fibre core was surrounded by two rings of air holes. In one of the microstructured fibres we introduced special absorbing inclusions placed outside the microstructure to attenuate leaky modes. We compared the performance of the surface plasmon resonance sensors based on the three fibres. We showed that the fibre bending enhances the resonance in all investigated fibres. The measured sensitivity of about 610 nm/RIUfor the refractive index of glycerol solution around 1.350 is similar in all fabricated sensors. However, the spectral width of the resonance curve is significantly lower for the fibre with inclusions suppressing the leaky modes.

  19. Surface plasmon optical antennae in the infrared region with high resonant efficiency and frequency selectivity.

    PubMed

    Ueno, Kosei; Sun, Quan; Mino, Masahiro; Itoh, Takumi; Oshikiri, Tomoya; Misawa, Hiroaki

    2016-08-08

    Infrared light has received attention for sensor applications, including fingerprint spectroscopy, in the bioengineering and security fields. Surface plasmon physics enables the operation of a light harvesting optical antenna. Gold nanochains exhibit localized surface plasmon resonance (LSPR) in the infrared region with high frequency selectivity. However, a feasible design for optical antennae with a higher resonant efficiency and frequency selectivity as a function of structural design and periodicity is still unknown. In the present study, we investigated the relationship between the resonant efficiency and frequency selectivity as a function of the structural design of gold nanochains and explored structural periodicity for obtaining highly frequency-selective optical antennae. An optical antenna design with higher resonant efficiency is proposed on the basis of its efficient interaction with non-polarized light.

  20. A band-pass plasmonic filter with dual-square ring resonator

    NASA Astrophysics Data System (ADS)

    Duan, Gaoyan; Lang, Peilin; Wang, Lulu; Yu, Li; Xiao, Jinghua

    2014-09-01

    In this paper, we show the simulation of a plasmonic band-pass filter which consists of two surface plasmon polaritons (SPPs) waveguides and a resonator in metal-insulator-metal (MIM) structure. The resonator is formed by two square rings and a patch between them. The patch is a tiny rectangle cavity in order to transfer the SPPs from one ring to the other. The finite element method (FEM) method is employed in simulation. The results show that the dual-ring resonator performs better than a single ring does. The 3 dB bandwidth near the peak wavelength λ = 1054 nm is merely 31.7 nm. The resonant wavelength can be shifted by changing the side length of the square ring. This narrow band-pass filter is easy to fabricate and has potential applications in future integrated optical circuits.

  1. Surface plasmon resonance (SPR) detection of Staphylococcal Enterotoxin A in food samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An automated and rapid method for detection of staphylococcal enterotoxins (SE) is needed. A sandwich assay was developed using a surface plasmon resonance (SPR) biosensor for detection of staphylococcal enterotoxin A (SEA) at subpicomolar concentration. Assay conditions were optimized for capturing...

  2. Detection of mycotoxins using imaging surface plasmon resonance (iSPR)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant progress has been made in the development of biosensors that can be used to detect mycotoxins. One technology that has been extensively tested is surface plasmon resonance (SPR). In 2003 a multi-toxin method was reported that detected aflatoxin B1 (AFB1), zearalenone (ZEA), fumonisin B1 ...

  3. Surface Plasmon Resonance Label-Free Monitoring of Antibody Antigen Interactions in Real Time

    ERIC Educational Resources Information Center

    Kausaite, Asta; van Dijk, Martijn; Castrop, Jan; Ramanaviciene, Almira; Baltrus, John P.; Acaite, Juzefa; Ramanavicius, Arunas

    2007-01-01

    Detection of biologically active compounds is one of the most important topics in molecular biology and biochemistry. One of the most promising detection methods is based on the application of surface plasmon resonance for label-free detection of biologically active compounds. This method allows one to monitor binding events in real time without…

  4. Nanorod mediated surface plasmon resonance sensor based on effective medium theory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel nanorod mediated surface plasmon resonance (SPR) sensor was investigated for enhancing sensitivity of the sensor. The theoretical model containing an anisotropic layer of nanorod was investigated using four-layer Fresnel equations and effective medium theory. The properties of the nanorod me...

  5. Rapid Detection of Nivalenol and Deoxynivalenol in Wheat Using Surface Plasmon Resonance Immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface plasmon resonance immunoassay using a monoclonal antibody was developed to measure nivalenol (NIV) and deoxynivalenol (DON) contamination in wheat. A DON-immobilized sensor chip having high sensitivity and stability was prepared, and an SPR detection procedure was developed. The competitiv...

  6. Using a surface plasmon resonance biosensor for rapid detection of salmonella typhimurium in chicken carcass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodborne pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance (SPR) biosensor was sensitive to the presence of Salmonella Typhimurium in chicken carcass. The Spr...

  7. Detection of benzimidazole carbamates and amino metabolites in liver by surface plasmon resonance-biosensor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two surface plasmon resonance (SPR) biosensor screening assays were developed and validated to detect 11 benzimidazole carbamate (BZT) and four amino-benzimidazole veterinary drug residues in liver tissue. The assays used polyclonal antibodies, raised in sheep, to detect BZTs and amino-benzimidazole...

  8. Multiplex surface plasmon resonance imaging platform for label-free detection of foodborne pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonellae are among the leading causes of foodborne outbreaks in the United States, and more rapid and efficient detection methods are needed. Surface plasmon resonance imaging (SPRi) is an emerging optical technique, which allows for rapid and label-free screening of multiple targets simultaneous...

  9. Thermal energy transfer by plasmon-resonant composite nanoparticles at pulse laser irradiation.

    PubMed

    Avetisyan, Yuri A; Yakunin, Alexander N; Tuchin, Valery V

    2012-04-01

    Heating of composite plasmon-resonant nanoparticles (spherical gold nanoshells) under pulse laser illumination is considered. The numerical solution of the time-dependent heat conduction equation accounting for spatial inhomogeneities of absorbed laser radiation is performed. Important features of temperature kinetics and thermal flux inside nanoparticles are analyzed. Possible applications of the observed effects in nanotechnology and medicine are discussed.

  10. Cholera toxin binding affinity and specificity for gangliosides determined by surface plasmon resonance

    SciTech Connect

    Kuziemko, G.M.; Stroh, M.; Stevens, R.C. |

    1996-05-21

    The present study determines the affinity of cholera toxin for the ganglioside series GM1, GM2, GM3, GD1A, GD1B, GT1B, asialo GM1, globotriosyl ceramide, and lactosyl ceramide using real time biospecific interaction analysis (surface plasmon resonance, SPR). SPR shows that cholera toxin preferably binds to gangliosides in the following sequence: GM1 > GM2 > GD1A > GM3 > GT1B > GD1B > asialo-GM1. The measured binding affinity of cholera toxin for the ganglioside sequence ranges from 4.61 {times} 10{sup {minus}12} M for GM1 to 1.88 {times} 10{sup {minus}10} M for asialo GM1. The picomolar values obtained by surface plasmon resonance are similar to K{sub d} values determined with whole-cell binding assays. Both whole-cell assays ans SPR measurements on synthetic membranes are higher than free solution measurements by several orders of magnitude. This difference may be caused by the effects of avidity and charged lipid head-groups, which may play a major role in the binding between cholera toxin, the receptor, and the membrane surface. The primary difference between free solution binding studies and surface plasmon resonance studies is that the latter technique is performed on surfaces resembling the cell membrane. Surface plasmon resonance has the further advantage of measuring apparent kinetic association and dissociation rates in real time, providing direct information about binding events at the membrane surface. 34 refs., 8 figs., 2 tabs.

  11. Analysis and design of terahertz antennas based on plasmonic resonant graphene sheets

    SciTech Connect

    Tamagnone, M.; Gomez-Diaz, J. S.; Perruisseau-Carrier, J.

    2012-12-01

    Resonant graphene antennas used as true interfaces between terahertz (THz) space waves and a source/detector are presented. It is shown that in addition to the high miniaturization related to the plasmonic nature of the resonance, graphene-based THz antenna favorably compare with typical metal implementations in terms of return loss and radiation efficiency. Graphene antennas will contribute to the development of miniature, efficient, and potentially transparent all-graphene THz transceivers for emerging communication and sensing application.

  12. Design of plasmonic photonic crystal resonant cavities for polarization sensitive infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Rosenberg, Jessie; Shenoi, Rajeev V.; Krishna, Sanjay; Painter, Oskar

    2010-02-01

    We design a polarization-sensitive resonator for use in midinfrared photodetectors, utilizing a photonic crystal cavity and a single or double-metal plasmonic waveguide to achieve enhanced detector efficiency due to superior optical confinement within the active region. As the cavity is highly frequency and polarization-sensitive, this resonator structure could be used in chip-based infrared spectrometers and cameras that can distinguish among different materials and temperatures to a high degree of precision.

  13. Three-dimensional composite metallodielectric nanostructure for enhanced surface plasmon resonance sensing

    NASA Astrophysics Data System (ADS)

    Chen, Haiping Matthew; Pang, Lin; Kher, Aditya; Fainman, Yeshaiahu

    2009-02-01

    The authors simulated, fabricated, and characterized a mushroomlike composite metallodielectric nanostructure that shows improved characteristics for surface plasmon resonance sensing applications with an enhancement in the normal electric field compared to the conventional nanohole structure. A fabrication method is introduced to give controllable linewidth by an oblique metal deposition process. A sensor built with the composite nanostructure was then used to determine the hydrophilicity of its surface by monitoring the resonant wavelength shift and computing the corresponding adsorption thickness.

  14. Dielectric Metal-Based Multilayers for Surface Plasmon Resonance with Enhanced Quality Factor of the Plasmonic Waves

    NASA Astrophysics Data System (ADS)

    Tran, Nhu Hoa Thi; Phan, Bach Thang; Yoon, Won Jung; Khym, Sungwon; Ju, Heongkyu

    2017-03-01

    We present improved quality factors of surface plasmon resonance (SPR) in a prism-based Krätschman configuration by using double the number of metal-dielectric layers for extended long-range surface plasmon. These multilayers lead to the coupling of multi-plasmonic waves for enhanced depth-to-width ratio (Γ) of the SPR dip of the reflectance curve. We use a transfer matrix approach to numerically simulate the curve of reflectance versus incident angle with each layer thickness optimized. We find that the four layers comprising doubled Teflon-Ag multilayers produce Γ higher than a single layer of Ag by a factor of about 122. These enhanced Γ (related to enhanced quality factor of the SPR wave) that lead to enlarged depth of SPR evanescent field penetration, can readily find applications in fluorescence detection with its efficiency elevated, which is required for fluorescence-based assays where weak fluorescent signals are expected, such as biological diagnosis that uses small volumes of liquid containing fluorescent dyes.

  15. Control of the plasmonic resonance of a graphene coated plasmonic nanoparticle array combined with a nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    De Sio, Luciano; Cataldi, Ugo; Bürgi, Thomas; Tabiryan, Nelson; Bunning, Timothy J.

    2016-07-01

    We report on the fabrication and characterization of a switchable plasmonic device based on a conductive graphene oxide (cGO) coated plasmonic nanoparticle (NP) array, layered with nematic liquid crystal (NLC) as an active medium. A monolayer of NPs has been immobilized on a glass substrate through electrostatic interaction, and then grown in place using nanochemistry. This monolayer is then coated with a thin (less then 100nm) cGO film which acts simultaneously as both an electro-conductive and active medium. The combination of the conductive NP array with a separate top cover substrate having both cGO and a standard LC alignment layer is used for aligning a NLC film in a hybrid configuration. The system is analysed in terms of morphological and electro-optical properties. The spectral response of the sample characterized after each element is added (air, cGO, NLC) reveals a red-shift of the localized plasmonic resonance (LPR) frequency of approximately 62nm with respect to the NP array surrounded by air. The application of an external voltage (8Vpp) is suitable to modulate (blue shift) the LPR frequency by approximately 22nm.

  16. Biochemical component identification by plasmonic improved whispering gallery mode optical resonance based sensor

    NASA Astrophysics Data System (ADS)

    Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Saetchnikov, Anton V.; Schweiger, Gustav; Ostendorf, Andreas

    2014-05-01

    Experimental data on detection and identification of variety of biochemical agents, such as proteins, microelements, antibiotic of different generation etc. in both single and multi component solutions under varied in wide range concentration analyzed on the light scattering parameters of whispering gallery mode optical resonance based sensor are represented. Multiplexing on parameters and components has been realized using developed fluidic sensor cell with fixed in adhesive layer dielectric microspheres and data processing. Biochemical component identification has been performed by developed network analysis techniques. Developed approach is demonstrated to be applicable both for single agent and for multi component biochemical analysis. Novel technique based on optical resonance on microring structures, plasmon resonance and identification tools has been developed. To improve a sensitivity of microring structures microspheres fixed by adhesive had been treated previously by gold nanoparticle solution. Another technique used thin film gold layers deposited on the substrate below adhesive. Both biomolecule and nanoparticle injections caused considerable changes of optical resonance spectra. Plasmonic gold layers under optimized thickness also improve parameters of optical resonance spectra. Biochemical component identification has been also performed by developed network analysis techniques both for single and for multi component solution. So advantages of plasmon enhancing optical microcavity resonance with multiparameter identification tools is used for development of a new platform for ultra sensitive label-free biomedical sensor.

  17. Monitoring drug-serum protein interactions for early ADME prediction through Surface Plasmon Resonance technology.

    PubMed

    Fabini, Edoardo; Danielson, U Helena

    2017-03-28

    Many molecules fail to reach the market due to poor pharmacokinetic (PK) properties, rendering the potential drug virtually unavailable for the primary target despite efficient administration to the body. PK properties of endogenous and exogenous compounds in mammals are dependent, among other factors, on their ability to interact with serum proteins. The extent of binding can greatly influence their ADME (adsorption, distribution, metabolism and execration) profile. Reliable and cost-effective bioavailability studies, early in the drug discovery process, can lead to an improvement of the success rate for compounds entering clinical trials. Optical biosensors based on surface plasmon resonance (SPR) detection emerged as an efficient approach to obtain large amounts of information about the binding of small molecules to serum proteins. Simple, automated and fast assays provide a good throughput, versatility and highly informative data output, rendering the methodology particularly suited for early screening. The ability to provide basic information on PK can be easily coupled to structure-activity relationship analysis. In this review, features of the technology and its employment for the study of serum protein-small molecule interactions are presented and discussed.

  18. Study of cell-matrix adhesion dynamics using surface plasmon resonance imaging ellipsometry.

    PubMed

    Kim, Se-Hwa; Chegal, Won; Doh, Junsang; Cho, Hyun Mo; Moon, Dae Won

    2011-04-06

    The interaction of cells with extracellular matrix, termed cell-matrix adhesions, importantly governs multiple cellular phenomena. Knowledge of the functional dynamics of cell-matrix adhesion could provide critical clues for understanding biological phenomena. We developed surface plasmon resonance imaging ellipsometry (SPRIE) to provide high contrast images of the cell-matrix interface in unlabeled living cells. To improve the contrast and sensitivity, the null-type imaging ellipsometry technique was integrated with an attenuated total reflection coupler. We verified that the imaged area of SPRIE was indeed a cell-matrix adhesion area by confocal microscopy imaging. Using SPRIE, we demonstrated that three different cell types exhibit distinct features of adhesion. SPRIE was applied to diverse biological systems, including during cell division, cell migration, and cell-cell communication. We imaged the cell-matrix anchorage of mitotic cells, providing the first label-free imaging of this interaction to our knowledge. We found that cell-cell communication can alter cell-matrix adhesion, possibly providing direct experimental evidence for cell-cell communication-mediated changes in cell adhesion. We also investigated shear-stress-induced adhesion dynamics in real time. Based on these data, we expect that SPRIE will be a useful methodology for studying the role of cell-matrix adhesion in important biological phenomena.

  19. Angle-tunable enhanced infrared reflection absorption spectroscopy via grating-coupled surface plasmon resonance.

    PubMed

    Petefish, Joseph W; Hillier, Andrew C

    2014-03-04

    Surface enhanced infrared absorption (SEIRA) spectroscopy is an attractive method for increasing the prominence of vibrational modes in infrared spectroscopy. To date, the majority of reports associated with SEIRA utilize localized surface plasmon resonance from metal nanoparticles to enhance electromagnetic fields in the region of analytes. Limited work has been performed using propagating surface plasmons as a method for SEIRA excitation. In this report, we demonstrate angle-tunable enhancement of vibrational stretching modes associated with a thin poly(methyl methacrylate) (PMMA) film that is coupled to a silver-coated diffraction grating. Gratings are fabricated using laser interference lithography to achieve precise surface periodicities, which can be used to generate surface plasmons that overlap with specific vibrational modes in the polymer film. Infrared reflection absorption spectra are presented for both bare silver and PMMA-coated silver gratings at a range of angles and polarization states. In addition, spectra were obtained with the grating direction oriented perpendicular and parallel to the infrared source in order to isolate plasmon enhancement effects. Optical simulations using the rigorous coupled-wave analysis method were used to identify the origin of the plasmon-induced enhancement. Angle-dependent absorption measurements achieved signal enhancements of more than 10-times the signal in the absence of the plasmon.

  20. Plasmon Resonances in Self-Assembled Two-Dimensional Au Nanocrystal Metamolecules.

    PubMed

    Greybush, Nicholas J; Liberal, Iñigo; Malassis, Ludivine; Kikkawa, James M; Engheta, Nader; Murray, Christopher B; Kagan, Cherie R

    2017-03-28

    We explore the evolution of plasmonic modes in two-dimensional nanocrystal oligomer "metamolecules" as the number of nanocrystals is systematically varied. Precise, hexagonally ordered Au nanocrystal oligomers with 1-31 members are assembled via capillary forces into polygonal topographic templates defined using electron-beam lithography. The visible and near-infrared scattering response of individual oligomers is measured by spatially resolved, polarized darkfield scattering spectroscopy. The response is highly sensitive to in-plane versus out-of-plane incident polarization, and we observe an exponentially saturating red shift in plasmon resonance wavelength as the number of nanocrystals per oligomer increases, in agreement with theoretical predictions. Simulations further elucidate the modes supported by the oligomers, including electric dipole and magnetic dipole resonances and their Fano interference. The single-oligomer sensitivity of our measurements also reveals the role of positional disorder in determining the wavelength and character of the plasmonic response. The progression of oligomer metamolecule structures studied here advances our understanding of fundamental plasmonic interactions in the transition regime between few-member plasmonic clusters and extended two-dimensional arrays.

  1. Standing-wave resonances in plasmonic nanoumbrella cavities for color generation and colorimetric refractive index sensor

    NASA Astrophysics Data System (ADS)

    Fan, Jiaorong; Li, Zhongyuan; Chen, Zhuojie; Wu, Wengang

    2016-10-01

    We theoretically investigate the hybridization of the elemental surface plasmons in umbrella-shape plasmonic nanostructures and experimentally demonstrate the implementation of plasmonic multicolor metasurfaces as well as their application in colorimetric sensing. The three-dimension metallic umbrella arrays consist of a periodic canopy-capped-nanopillars with metal-coated sidewall and a backplane metal-film to form vertical nanocavity of canopy and film. Plasmonic coupling and energy confinement in nanocavity induce a noticeably resonance narrowing of multispectral reflection. The metasurfaced nanostructures appeared in vibrant and tunable colors with broad gamut derived from color blending mechanism due to multiple, narrow-band resonances. Vivid colors varied from red, yellow, green, blue to violet are easily achieved. It is also shown that such plasmonic metasurfaces can work as the feasible and real-time colorimetric refractive index sensor by measuring the distinct color variation to glucose concentration changes. Our sensor scheme shows its spectral sensitivity in the periodic umbrella array with respect to the refractive index change to be 242.5 nm/RIU with a figure of merit of 7.3. Furthermore, a refractive index resolution of colorimetric sensing up to 0.025 RIU has been accomplished.

  2. Optical properties of surface plasmon resonances of coupled metallic nanorods.

    PubMed

    Smythe, Elizabeth J; Cubukcu, Ertugrul; Capasso, Federico

    2007-06-11

    We present a systematic study of optical antenna arrays, in which the effects of coupling between the antennas, as well as of the antenna length, on the reflection spectra are investigated and compared. Such arrays can be fabricated on the facet of a fiber, and we propose a photonic device, a plasmonic optical antenna fiber probe, that can potentially be used for in-situ chemical and biological detection and surface-enhanced Raman scattering.

  3. Study on Dielectric Function Models for Surface Plasmon Resonance Structure

    PubMed Central

    Adikan, Faisal Rafiq Mahamd

    2014-01-01

    The most common permittivity function models are compared and identifying the best model for further studies is desired. For this study, simulations using several different models and an analytical analysis on a practical surface Plasmon structure were done with an accuracy of ∼94.4% with respect to experimental data. Finite element method, combined with dielectric properties extracted from the Brendel-Bormann function model, was utilized, the latter being chosen from a comparative study on four available models. PMID:24616635

  4. Dressing plasmon resonance with particle-microcavity architecture for efficient nano-optical trapping and sensing.

    PubMed

    Zhang, Haixi; Zhou, Yanyan; Yu, Xia; Luan, Feng; Xu, Jianbin; Ong, Hock-Chun; Ho, Ho-Pui

    2014-02-15

    We propose a particle-microcavity scheme for efficient optical trapping and sensing. When a resonant plasmonic nanoparticle (NP) is placed inside a microcavity with high Q-factor, sensitivity is enhanced in the far-field extinction while near-field around the NP is barely affected. Stable near-field and high sensitivity for optical trapping and ultrasensitive detection of nanosized targets are therefore realized simultaneously. Such a particle-microcavity system opens up a new hybrid nanophotonic device platform that combines the unique merits of conventional and plasmonic integrated photonics.

  5. Complex dielectric constant of various biomolecules as a function of wavelength using surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Paliwal, Ayushi; Tomar, Monika; Gupta, Vinay

    2014-07-01

    Present study focuses on determination of complex dielectric constant of biomolecules as function of frequency by means of surface plasmon resonance (SPR) technique without losing their biofunctionality. Surface plasmon modes have been excited in Kretschmann configuration at interface of ZnO-Au thin films. Various biomolecules (glucose oxidase, cholesterol oxidase, urease, and uricase) have been immobilized successfully on surface of ZnO thin film by electrostatic interaction. SPR reflectance curves for all biomolecules were recorded separately at different wavelengths (407-635 nm). Complex dielectric constant was determined by fitting the experimental SPR data with Fresnel's equations. Dielectric constant of all biomolecules shows frequency dispersion and attributed to ionic polarization.

  6. Surface plasmon resonance of Au-Cu bimetallic nanoparticles predicted by a quasi-chemical model

    NASA Astrophysics Data System (ADS)

    Su, Yen-Hsun; Wang, Wen-Lin

    2013-10-01

    Au-Cu alloys are functional materials with nonlinear optical applications. However, the optical properties of such alloys are difficult to predict due to the random mixing of materials. In this paper, we present a quasi-chemical model to simulate the optical properties of Au-Cu alloy systems based on the mixing of Gibbs free energy. This model is also able to predict the position of the surface plasmon resonance peaks for Au-Cu alloy nanoparticles. The model can be applied to predict the optical properties of alloy systems in the fields of plasmonics and nanophotonics.

  7. High performing phase-based surface plasmon resonance sensing from metallic nanohole arrays

    SciTech Connect

    Cao, Z. L.; Wong, S. L.; Ong, H. C.; Wu, S. Y.; Ho, H. P.

    2014-04-28

    We show the spectral figure-of-merit (FOM) from nanohole arrays can be larger than 1900/RIU by phase-based surface plasmon resonance. By using temporal coupled mode theory, we find the p-s polarization phase jump is the sharpest when both the absorption and radiative decay rates of surface plasmon polaritons are matched, yielding an extremely small spectral differential phase linewidth and thus superior FOM. The result is supported by numerical simulation and experiment. As a demonstration, we show the phase detection outperforms the conventional spectral counterpart significantly by sensing the binding of bovine serum albumin antibodies under identical condition.

  8. Fiber Optic Surface Plasmon Resonance-Based Biosensor Technique: Fabrication, Advancement, and Application.

    PubMed

    Liang, Gaoling; Luo, Zewei; Liu, Kunping; Wang, Yimin; Dai, Jianxiong; Duan, Yixiang

    2016-05-03

    Fiber optic-based biosensors with surface plasmon resonance (SPR) technology are advanced label-free optical biosensing methods. They have brought tremendous progress in the sensing of various chemical and biological species. This review summarizes four sensing configurations (prism, grating, waveguide, and fiber optic) with two ways, attenuated total reflection (ATR) and diffraction, to excite the surface plasmons. Meanwhile, the designs of different probes (U-bent, tapered, and other probes) are also described. Finally, four major types of biosensors, immunosensor, DNA biosensor, enzyme biosensor, and living cell biosensor, are discussed in detail for their sensing principles and applications. Future prospects of fiber optic-based SPR sensor technology are discussed.

  9. Novel Piezoelectric Effect and Surface Plasmon Resonance-Based Elements for MEMS Applications

    PubMed Central

    Ponelyte, Sigita; Palevicius, Arvydas

    2014-01-01

    This paper covers research on novel thin films with periodical microstructure—optical elements, exhibiting a combination of piezoelectric and surface plasmon resonance effects. The research results showed that incorporation of Ag nanoparticles in novel piezoelectric—plasmonic elements shift a dominating peak in the visible light spectrum. This optical window is essential in the design of optical elements for sensing systems. Novel optical elements can be tunable under defined bias and change its main grating parameters (depth and width) influencing the response of diffraction efficiencies. These elements allow opening new avenues in the design of more sensitive and multifunctional microdevices. PMID:24747733

  10. Surface plasmon resonance optical sensor and antibacterial activities of biosynthesized silver nanoparticles.

    PubMed

    Bindhu, M R; Umadevi, M

    2014-01-01

    Silver nanoparticles were prepared using aqueous fruit extract of Ananas comosus as reducing agent. These silver nanoparticles showed surface plasmon peak at 439 nm. They were monodispersed and spherical in shape with an average particle size of 10 nm. The crystallinity of these nanoparticles was evident from clear lattice fringes in the HRTEM images and bright circular spots in the SAED pattern. The antibacterial activities of prepared nanoparticles were found to be size-dependent, the smaller nanoparticles showing more bactericidal effect. Aqueous Zn(2+) and Cu(4+) selectivity and sensitivity study of this green synthesized nanoparticle was performed by optical sensor based surface plasmon resonance (SPR) at room temperature.

  11. Surface plasmon resonance optical sensor and antibacterial activities of biosynthesized silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Bindhu, M. R.; Umadevi, M.

    2014-03-01

    Silver nanoparticles were prepared using aqueous fruit extract of Ananas comosus as reducing agent. These silver nanoparticles showed surface plasmon peak at 439 nm. They were monodispersed and spherical in shape with an average particle size of 10 nm. The crystallinity of these nanoparticles was evident from clear lattice fringes in the HRTEM images and bright circular spots in the SAED pattern. The antibacterial activities of prepared nanoparticles were found to be size-dependent, the smaller nanoparticles showing more bactericidal effect. Aqueous Zn2+ and Cu4+ selectivity and sensitivity study of this green synthesized nanoparticle was performed by optical sensor based surface plasmon resonance (SPR) at room temperature.

  12. Nanofocusing beyond the near-field diffraction limit via plasmonic Fano resonance.

    PubMed

    Song, Maowen; Wang, Changtao; Zhao, Zeyu; Pu, Mingbo; Liu, Ling; Zhang, Wei; Yu, Honglin; Luo, Xiangang

    2016-01-21

    The past decade has witnessed a great deal of optical systems designed for exceeding the Abbe's diffraction limit. Unfortunately, a deep subwavelength spot is obtained at the price of extremely short focal length, which is indeed a near-field diffraction limit that could rarely go beyond in the nanofocusing device. One method to mitigate such a problem is to set up a rapid oscillatory electromagnetic field that converges at the prescribed focus. However, abrupt modulation of phase and amplitude within a small fraction of a wavelength seems to be the main obstacle in the visible regime, aggravated by loss and plasmonic features that come into function. In this paper, we propose a periodically repeated ring-disk complementary structure to break the near-field diffraction limit via plasmonic Fano resonance, originating from the interference between the complex hybrid plasmon resonance and the continuum of propagating waves through the silver film. This plasmonic Fano resonance introduces a π phase jump in the adjacent channels and amplitude modulation to achieve radiationless electromagnetic interference. As a result, deep subwavelength spots as small as 0.0045λ(2) at 36 nm above the silver film have been numerically demonstrated. This plate holds promise for nanolithography, subdiffraction imaging and microscopy.

  13. Localized surface plasmon resonances in spatially dispersive nano-objects: phenomenological treatise.

    PubMed

    Ginzburg, Pavel; Zayats, Anatoly V

    2013-05-28

    Nonlocal optical response of materials, important at the nanometric scale, influences numerous optical phenomena, such as electromagnetic field confinement and spectral characteristics of plasmonic resonances. Here, we present a general phenomenological approach to account for nonlocal material polarizabilities in nanoscale metal particles. The problem of nonlocal plasmonic resonances is formulated by an integro-differential equation in a space domain and solved by adopting its weak form, implemented in the finite element method, thus, dispensing with the requirements on additional boundary conditions. As an example, nonlocal smearing effects in plasmonic nanorods of various cross sections and nanotubes have been considered. Clear signature of nonlocality manifests itself in the interference fringes in the potential profile and a significant frequency shift of the localized surface plasmon resonances. These effects are especially important for nanoparticles with geometrical features comparable to the de Broglie wavelengths of electrons participating in the light-matter interactions. The proposed method provides a universal tool for phenomenological account of nonlocalities of any kind with the only requirement of linearity in system's response.

  14. Plasmonic hysteresis: temperature dependent resonance of vanadium-dioxide coated gold nanoparticle arrays

    NASA Astrophysics Data System (ADS)

    Ferrara, Davon; Nag, Joyeeta; Donev, Eugene; Suh, Jae; Haglund, Richard

    2009-03-01

    The optical properties of metal nanostructures are dominated by the free-electron, or plasmonic, response of the material. In the case of metal nanoparticles, this leads to a resonant extinction with wavelength determined by the particles' size, shape, material, and surrounding dielectric. Vanadium-dioxide has a hysteretic transition from a semiconductor to a metal about 68C accompanied by a change in its structural, electrical and optical properties. Using vanadium dioxide as a thermochromic dielectric switch, we map out the hysteresis of the plasmonic resonance of gold nanoparticle arrays coated with the metal-oxide as a function of temperature. To study this plasmonic dependence on temperature, a sample of 20nm thick Au nanoparticle arrays with various particle sizes and grating constants were coated with a 60nm thick vanadium dioxide film. We find that near the transition, the particle plasmon resonance can shift position over 250nm. Measurements of the line shape show the effects of strong correlation in the vicinity of the switching temperatures.

  15. Analysis of a highly birefringent asymmetric photonic crystal fibre based on a surface plasmon resonance sensor

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Wang, Famei; Zheng, Shijie; Sun, Tao; Lv, Jingwei; Liu, Qiang; Yang, Lin; Mu, Haiwei; Chu, Paul K.

    2016-07-01

    A highly birefringent photonic crystal fibre is proposed and characterized based on a surface plasmon resonance sensor. The birefringence of the sensor is numerically analyzed by the finite-element method. In the numerical simulation, the resonance wavelength can be directly positioned at this birefringence abrupt change point and the depth of the abrupt change of birefringence reflects the intensity of excited surface plasmon. Consequently, the novel approach can accurately locate the resonance peak of the system without analyzing the loss spectrum. Simulated average sensitivity is as high as 1131 nm/RIU, corresponding to a resolution of 1 × 10-4 RIU in this sensor. Therefore, results obtained via the approach not only show polarization independence and less noble metal consumption, but also reveal better performance in terms of accuracy and computation efficiency.

  16. Effect of finite metallic grating size on Rayleigh anomaly-surface plasmon polariton resonances

    PubMed Central

    Ren, Fanghui; Kim, Kyoung-Youm; Chong, Xinyuan; Wang, Alan X.

    2015-01-01

    Rayleigh anomalies (RAs) and surface plasmon polaritons (SPPs) on subwavelength metallic gratings play pivotal roles in many interesting phenomena such as extraordinary optical transmission. In this work, we present a theoretical analysis of the effect of finite metallic grating size on RA-SPP resonances based on the combination of rigorous coupled wave analysis and finite aperture diffraction. One-dimensional arrays of gold subwavelength gratings with different device sizes were fabricated and the optical transmission spectra were measured. As the grating size shrinks, the broadening of the RA-SPP resonances is predicted by the theoretical model. For the first order RA-SPP resonances, the results from this model are in good agreement with the spectra measured from the fabricated plasmonic gratings. PMID:26561155

  17. Plasmon coupling of magnetic resonances in an asymmetric gold semishell

    NASA Astrophysics Data System (ADS)

    Ye, Jian; Kong, Yan; Liu, Cheng

    2016-05-01

    The generation of magnetic dipole resonances in metallic nanostructures is of great importance for constructing near-zero or even negative refractive index metamaterials. Commonly, planar two-dimensional (2D) split-ring resonators or relevant structures are basic elements of metamaterials. In this work, we introduce a three-dimensional (3D) asymmetric Au semishell composed of two nanocups with a face-to-face geometry and demonstrate two distinct magnetic resonances spontaneously in the visible-near infrared optical wavelength regime. These two magnetic resonances are from constructive and destructive hybridization of magnetic dipoles of individual nanocups in the asymmetric semishell. In contrast, complete cancellation of magnetic dipoles in the symmetric semishell leads to only a pronounced electric mode with near-zero magnetic dipole moment. These 3D asymmetric resonators provide new ways for engineering hybrid resonant modes and ultra-high near-field enhancement for the design of 3D metamaterials.

  18. Localized surface plasmon polariton resonance in holographically structured Al-doped ZnO

    NASA Astrophysics Data System (ADS)

    George, David; Li, Li; Jiang, Yan; Lowell, David; Mao, Michelle; Hassan, Safaa; Ding, Jun; Cui, Jingbiao; Zhang, Hualiang; Philipose, Usha; Lin, Yuankun

    2016-07-01

    In this paper, we studied the localized surface plasmon polariton (SPP) resonance in hole arrays in transparent conducting aluminum-doped zinc oxide (AZO). CMOS-compatible fabrication process was demonstrated for the AZO devices. The localized SPP resonance was observed and confirmed by electromagnetic simulations. Using a standing wave model, the observed SPP was dominated by the standing-wave resonance along (1,1) direction in square lattices. This research lays the groundwork for a fabrication technique that can contribute to the core technology of future integrated photonics through its extension into tunable conductive materials.

  19. A novel optical pressure sensor based on surface plasmon polariton resonator

    NASA Astrophysics Data System (ADS)

    Wu, Jing; Lang, Peilin; Chen, Xi; Zhang, Ru

    2016-02-01

    We propose a Metal-Insulator-Metal structure consists of two surface plasmon polaritons (SPPs) and an H-shaped resonator. The reflectance spectrum is numerically simulated by the two-dimensional finite-difference time-domain method. The results show that this structure can act as a pressure sensor. To our knowledge, this is the first proposal to utilize the SPP resonator to form a pressure sensor. The size of the SPP resonator can be as small as a few hundred nanometers. The nano-scale pressure sensor opens a wide field for potential applications in biological and biomedical engineering.

  20. Resonance Coupling in Plasmonic Nanomatryoshka Homo- and Heterodimers

    DTIC Science & Technology

    2016-08-16

    creativecommons.org/licenses/by/4.0/). [http://dx.doi.org/10.1063/1.4953351] I. INTRODUCTION The optical characteristics of noble metallic structures in nanoscale...compositions.13–18 In this report, we extend our study to the NM structure with different metal compositions and sizes. This method allows us...ing the structural dimensions and choosing the same metal for both units, we observed bonding (σ and π) and antibonding (σ∗ and π∗) plasmon modes for

  1. Surface plasmon-polariton resonance at diffraction of THz radiation on semiconductor gratings

    NASA Astrophysics Data System (ADS)

    Spevak, I. S.; Kuzmenko, A. A.; Tymchenko, M.; Gavrikov, V. K.; Shulga, V. M.; Feng, J.; Sun, H. B.; Kamenev, Yu. E.; Kats, A. V.

    2016-08-01

    Resonance diffraction of THz hidrogen cyanide laser radiation on a semiconductor (InSb) grating is studied both experimentally and theoretically. The specular reflectivity suppression due to the resonance excitation of the THz surface plasmon-polariton is observed on a pure semiconductor grating and on semiconductor gratings covered with a thin dielectric layer. The dielectric coating of the grating results in the resonance shift and widening depending both on the layer thickness and dielectric properties. A simple analytical theory of the resonance diffraction on rather shallow gratings covered with a dielectric layer is presented, and the results are in a good accordance with the experimental data. Analytical expressions for the resonance shift and broadening are essential for the resonance properties understanding and useful for sensing data interpretation of the agents deposited on the grating surface.

  2. Achieving High Spatial Resolution Surface Plasmon Resonance Microscopy with Image Reconstruction.

    PubMed

    Yu, Hui; Shan, Xiaonan; Wang, Shaopeng; Tao, Nongjian

    2017-03-07

    Surface plasmon resonance microscopy (SPRM) is a powerful platform for biomedical imaging and molecular binding kinetics analysis. However, the spatial resolution of SPRM along the plasmon propagation direction (longitudinal) is determined by the decaying length of the plasmonic wave, which can be as large as tens of microns. Different methods have been proposed to improve the spatial resolution, but each at the expense of decreased sensitivity or temporal resolution. Here we present a method to achieve high spatial resolution SPRM based on deconvolution of complex field. The method does not require additional optical setup and improves the spatial resolution in the longitudinal direction. We applied the method to image nanoparticles and achieved close-to-diffraction limit resolution in both longitudinal and transverse directions.

  3. Surface-enhanced Raman spectroscopy on a surface plasmon resonance biosensor platform for gene diagnostics

    NASA Astrophysics Data System (ADS)

    Yuan, W.; Ho, H. P.; Suen, Y. K.; Kong, S. K.; Lin, Chinlon; Prasad, Paras N.; Li, J.; Ong, Daniel H. C.

    2008-02-01

    We propose to integrate the surface-enhanced Raman spectroscopy (SERS) detection capability with a surface plasmon resonance (SPR) biosensor platform. As a demonstration setup, the experimental scheme is built from a Total Internal Reflection Fluorescence (TIRF) microscope. The sample surface is a gold-coated plasmonic crystal substrate. Two oligonucleotide (ODN) probes that have been labeled with two different Raman active dyes are used to achieve a sandwich assay of target ODNs or polynucleotide. Upon complementary hybridizations between the target and probe ODNs, the target can be identified by detecting the narrow-band spectroscopic fingerprints of the Raman tags. This concept has high potential for achieving multiplexed detection of ODN targets because a very large number of probes can be incorporated to the plasmonic crystal substrate, which may find applications in gene based diseases diagnostics. We also explored the detection of single molecules and achieved some preliminary results.

  4. Evaluation of an affinity-amplified immunoassay of graphene oxide using surface plasmon resonance biosensors

    NASA Astrophysics Data System (ADS)

    Chiu, Nan-Fu; Huang, Teng-Yi; Kuo, Chun-Chuan

    2015-05-01

    We describe a fundamental study on the plasmonic properties and advanced biosensing mechanisms of functionalized graphene. We discuss a specific design using modified carboxyl groups, which can modulate surface plasmon (SP) coupling and provide an advantage for their binding to the sensing layer with high-performance affinity in an immunological reaction. The functionalized graphene-based surface plasmon resonance (SPR) biosensors have three advantages: high performance, high sensitivity, and excellent molecular kinetic response. In the future, functionalized graphene sheets will make a unique contribution to photonic and SPR diagnosis devices. We wish to highlight the essential characteristics of functionalized graphene-based SPR biosensors to assist researchers in developing and advancing suitable biosensors for unique applications.

  5. Electrically controlled plasmonic lasing resonances with silver nanoparticles embedded in amplifying nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Wang, Chin; Deng, Luogen

    2014-11-01

    We demonstrated an electrical control of coherent plasmonic random lasing with very diluted Ag nanoparticles dispersed in a dye-doped nematic liquid crystal (NLC), in which the external electric field dependent emission intensity and frequency-splitting were recorded. A modified rate equation model is proposed to interpret the observed coherent lasing, which is a manifestation of the double enhancements caused by the plasmon-polariton near-fields of Ag particles on the population inversion of laser dye molecules and on the optical energy density of lasing modes. The featured laser quenching as weakening the applied field indicates that the present lasing resonances are very sensitive to the fluctuant dielectric perturbations in the NLC host, and are thus most likely associated with some coupled plasmonic oscillations among the metal nanoparticles.

  6. Recent Development of Plasmonic Resonance-Based Photocatalysis and Photovoltaics for Solar Utilization.

    PubMed

    Fan, Wenguang; Leung, Michael K H

    2016-02-02

    Increasing utilization of solar energy is an effective strategy to tackle our energy and energy-related environmental issues. Both solar photocatalysis (PC) and solar photovoltaics (PV) have high potential to develop technologies of many practical applications. Substantial research efforts are devoted to enhancing visible light activation of the photoelectrocatalytic reactions by various modifications of nanostructured semiconductors. This review paper emphasizes the recent advancement in material modifications by means of the promising localized surface plasmonic resonance (LSPR) mechanisms. The principles of LSPR and its effects on the photonic efficiency of PV and PC are discussed here. Many research findings reveal the promise of Au and Ag plasmonic nanoparticles (NPs). Continual investigation for increasing the stability of the plasmonic NPs will be fruitful.

  7. Localized surface plasmon resonance and refractive index sensitivity of vacuum-evaporated nanostructured gold thin films

    NASA Astrophysics Data System (ADS)

    Rai, V. N.; Srivastava, A. K.; Mukherjee, C.; Deb, S. K.

    2016-01-01

    Plasmonic properties of vacuum-evaporated nanostructured gold thin films having different types of nanoparticles are presented. The films with thickness ≥6 nm show the presence of nanorods having non-cylindrical shape with triangular base. Two characteristic plasmon bands have been recorded in absorption spectra. First one occurs below 500 nm and the other one at higher wavelength side. Both the peaks show dependence on the dielectric property of surroundings. The higher wavelength localized surface plasmon resonance peak shifts to higher wavelength with an increase in the nanoparticle size, surface roughness and refractive index of the surrounding (methylene blue dye coating). This shows that such thin films can be used as sensor for organic molecules with a refractive index sensitivity ranging from 250 to 305 nm/RIU (refractive index unit).

  8. Comparing resonant photon tunneling via cavity modes and Tamm plasmon polariton modes in metal-coated Bragg mirrors.

    PubMed

    Leosson, K; Shayestehaminzadeh, S; Tryggvason, T K; Kossoy, A; Agnarsson, B; Magnus, F; Olafsson, S; Gudmundsson, J T; Magnusson, E B; Shelykh, I A

    2012-10-01

    Resonant photon tunneling was investigated experimentally in multilayer structures containing a high-contrast (TiO(2)/SiO(2)) Bragg mirror capped with a semitransparent gold film. Transmission via a fundamental cavity resonance was compared with transmission via the Tamm plasmon polariton resonance that appears at the interface between a metal film and a one-dimensional photonic bandgap structure. The Tamm-plasmon-mediated transmission exhibits a smaller dependence on the angle and polarization of the incident light for similar values of peak transmission, resonance wavelength, and finesse. Implications for transparent electrical contacts based on resonant tunneling structures are discussed.

  9. Theoretical limit of localized surface plasmon resonance sensitivity to local refractive index change and its comparison to conventional surface plasmon resonance sensor.

    PubMed

    Zalyubovskiy, Sergiy J; Bogdanova, Maria; Deinega, Alexei; Lozovik, Yurii; Pris, Andrew D; An, Kwang Hyup; Hall, W Paige; Potyrailo, Radislav A

    2012-06-01

    In this paper, the theoretical sensitivity limit of the localized surface plasmon resonance (LSPR) to the surrounding dielectric environment is discussed. The presented theoretical analysis of the LSPR phenomenon is based on perturbation theory. Derived results can be further simplified assuming quasistatic limit. The developed theory shows that LSPR has a detection capability limit independent of the particle shape or arrangement. For a given structure, sensitivity is directly proportional to the resonance wavelength and depends on the fraction of the electromagnetic energy confined within the sensing volume. This fraction is always less than unity; therefore, one should not expect to find an optimized nanofeature geometry with a dramatic increase in sensitivity at a given wavelength. All theoretical results are supported by finite-difference time-domain calculations for gold nanoparticles of different geometries (rings, split rings, paired rings, and ring sandwiches). Numerical sensitivity calculations based on the shift of the extinction peak are in good agreement with values estimated by perturbation theory. Numerical analysis shows that, for thin (≤10 nm) analyte layers, sensitivity of the LSPR is comparable with a traditional surface plasmon resonance sensor and LSPR has the potential to be significantly less sensitive to temperature fluctuations.

  10. The influence of edge and corner evolution on plasmon properties and resonant edge effect in gold nanoplatelets.

    PubMed

    Xu, Xi-Bin; Luo, Jiang-Shan; Liu, Miao; Wang, Yu-Ying; Yi, Zao; Li, Xi-Bo; Yi, You-Gen; Tang, Yong-Jian

    2015-01-28

    In this paper a simulation of the properties of surface plasmons on gold nanoplatelets with various cross-sections inscribed in a circle and an investigation of their field distributions to assign multiple SPRs are described. The manipulated propagation can be obtained through the evolution of edges and corners. Furthermore, the particle morphology and the associated spectral positions alone do not uniquely reflect the important details of the local field distribution or the resonance modes. The plasmon modes were investigated and found to be mainly excited along the edges and in the side and sloped side surfaces. The strong field distributions can generally be found around the corners and how the plasmons transmit through the corners to adjacent edges was also investigated. Besides the plasmons excited along the edges as were found for the triangular nanoplatelets, plasmons were excited in the interior region of the triangular surfaces and were also investigated. Despite this in the infrared region, plasmon modes were found to be along the edges for the hexagonal nanoplatelets. Also, it can be seen that the change of nanoplatelet thickness can support different plasmon modes ranging from dipolar resonance mode to quadrupole resonance mode. The thickness far below the skin depth can display complex plasmon modes along the edges and on the side and sloping side surfaces as well as the strong coupling between the top and bottom surfaces. The observed plasmon resonance modes in this simulation reflect the interference of all these contributions including the plasmons along the edges and on the side surfaces. This is an essential step towards a thorough understanding of plasmon modes and the effect of edge and corner evolution in polygonous nanoplatelets.

  11. Spoof surface plasmons resonance effect and tunable electric response of improved metamaterial in the terahertz regime

    NASA Astrophysics Data System (ADS)

    Wang, Yue; Zhang, Li-Ying; Mei, Jin-Shuo; Zhang, Wen-Chao; Tong, Yi-Jing

    2015-12-01

    We propose an improved design and numerical study of an optimized tunable plasmonics artificial material resonator in the terahertz regime. We demonstrate that tunability can be realized with a transmission intensity as much as ˜61% in the lower frequency resonance, which is implemented through the effect of photoconductive switching under photoexcitation. In the higher frequency resonance, we show that spoof surface plasmons along the interface of metal/dielectric provide new types of electromagnetic resonances. Our approach opens up possibilities for the interface of metamaterial and plasmonics to be applied to optically tunable THz switching. Project supported by the National Natural Science Foundation of China (Grant No. 61201075), the Natural Science Foundation of Heilongjiang Province, China (Grant No. F2015039), the Young Scholar Project of Heilongjiang Provincial Education Bureau, China (Grant No. 1254G021), the China Postdoctoral Science Foundation (Grant No. 2012M511507), and the Science Funds for the Young Innovative Talents of Harbin University of Science and Technology, China (Grant No. 201302).

  12. Giant enhancement of second harmonic generation by engineering double plasmonic resonances at nanoscale.

    PubMed

    Ren, Ming-Liang; Liu, Si-Yun; Wang, Ben-Li; Chen, Bao-Qin; Li, Jiafang; Li, Zhi-Yuan

    2014-11-17

    We have investigated second harmonic generation (SHG) from Ag-coated LiNbO₃(LN) core-shell nanocuboids and found that giant SHG can occur via deliberately designed double plasmonic resonances. By controlling the aspect ratio, we can tune fundamental wave (FW) and SHG signal to match the longitudinal and transverse plasmonic modes simultaneously, and achieve giant enhancement of SHG by 3 × 10(5) in comparison to a bare LN nanocuboid and by about one order of magnitude to the case adopting only single plasmonic resonance. The underlying key physics is that the double-resonance nanoparticle enables greatly enhanced trapping and harvesting of incident FW energy, efficient internal transfer of optical energy from FW to the SHG signal, and much improved power to transport the SHG energy from the nanoparticle to the far-field region. The proposed double-resonance nanostructure can serve as an efficient subwavelength coherent light source through SHG and enable flexible engineering of light-matter interaction at nanoscale.

  13. Localized and propagating surface plasmon resonances in aperture-based third harmonic generation.

    PubMed

    Nezami, Mohammadreza S; Gordon, Reuven

    2015-12-14

    We investigate the influence of localized and propagating surface plasmons on third harmonic generation from rectangular apertures in metal films. We designed optimal aperture array structures by using finite-difference time-domain simulations with nonlinear scattering theory. From this design space, we fabricated and measured the third harmonic in the region of maximal performance. We find the highest third harmonic conversion efficiency when the localized resonance is tuned to the fundamental wavelength and the propagating (Bragg) resonance is tuned to the third harmonic; this is 2.5 times larger than the case where the both localized and propagating are tuned to the fundamental wavelength. The two remaining configurations where also investigated with much lower conversion efficiency. When the Bragg resonance is tuned to the third harmonic, directivity improves the collection of third harmonic emission. On the other hand, due to the inherent absorption of gold at the third harmonic, tuning the localized surface plasmon resonance to the third harmonic is less beneficial. All cases showed quantitative agreement with the original theoretical analysis. This work points towards an optimal design criterion for harmonic generation from thin plasmonic metasurfaces.

  14. Tunable THz wave absorption by graphene-assisted plasmonic metasurfaces based on metallic split ring resonators

    NASA Astrophysics Data System (ADS)

    Ahmadivand, Arash; Sinha, Raju; Karabiyik, Mustafa; Vabbina, Phani Kiran; Gerislioglu, Burak; Kaya, Serkan; Pala, Nezih

    2017-01-01

    Graphene plasmonics has been introduced as a novel platform to design various nano- and microstructures to function in a wide range of spectrum from optical to THz frequencies. Herein, we propose a tunable plasmonic metamaterial in the THz regime by using metallic (silver) concentric microscale split ring resonator arrays on a multilayer metasurface composed of silica and silicon layers. We obtained an absorption percentage of 47.9% including two strong Fano resonant dips in THz regime for the purely plasmonic metamaterial without graphene layer. Considering the data of an atomic graphene sheet (with the thickness of 0.35 nm) in both analytical and experimental regimes obtained by prior works, we employed a graphene layer under concentric split ring resonator arrays and above the multilayer metasurface to enhance the absorption ratio in THz bandwidth. Our numerical and analytical results proved that the presence of a thin graphene layer enhances the absorption coefficient of MM to 64.35%, at the highest peak in absorption profile that corresponds to the Fano dip position. We also have shown that changing the intrinsic characteristics of graphene sheet leads to shifts in the position of Fano dips and variations in the absorption efficiency. The maximum percentage of absorption ( 67%) was obtained for graphene-based MM with graphene layer with dissipative loss factor of 1477 Ω. Employing the antisymmetric feature of the split ring resonators, the proposed graphene-based metamaterial with strong polarization dependency is highly sensitive to the polarization angle of the incident THz beam.

  15. Absorption enhancement in amorphous silicon thin films via plasmonic resonances in nickel silicide nanoparticles

    NASA Astrophysics Data System (ADS)

    Hachtel, Jordan; Shen, Xiao; Pantelides, Sokrates; Sachan, Ritesh; Gonzalez, Carlos; Dyck, Ondrej; Fu, Shaofang; Kalnayaraman, Ramki; Rack, Phillip; Duscher, Gerd

    2013-03-01

    Silicon is a near ideal material for photovoltaics due to its low cost, abundance, and well documented optical properties. The sole detriment of Si in photovoltaics is poor absorption in the infrared. Nanoparticle surface plasmon resonances are predicted to increase absorption by scattering to angles greater than the critical angle for total internal reflection (16° for a Si/air interface), trapping the light in the film. Experiments confirm that nickel silicide nanoparticles embedded in amorphous silicon increases absorption significantly in the infrared. However, it remains to be seen if electron-hole pair generation is increased in the solar cell, or whether the light is absorbed by the nanoparticles themselves. The nature of the absorption is explored by a study of the surface plasmon resonances through electron energy loss spectrometry and scanning transmission electron microscopy experiments, as well as first principles density functional theory calculations. Initial experimental results do not show strong plasmon resonances on the nanoparticle surfaces. Calculations of the optical properties of the nickel silicide particles in amorphous silicon are performed to understand why this resonance is suppressed. Work supported by NSF EPS 1004083 (TN-SCORE).

  16. Competition Between Resonant Plasmonic Coupling and Electrostatic Interaction in Reduced Graphene Oxide Quantum Dots.

    PubMed

    Karna, Sanjay; Mahat, Meg; Choi, Tae-Youl; Shimada, Ryoko; Wang, Zhiming; Neogi, Arup

    2016-11-22

    The light emission from reduced graphene oxide quantum dots (rGO-QDs) exhibit a significant enhancement in photoluminescence (PL) due to localized surface plasmon (LSP) interactions. Silver and gold nanoparticles (NPs) coupled to rGO nanoparticles exhibit the effect of resonant LSP coupling on the emission processes. Enhancement of the radiative recombination rate in the presence of Ag-NPs induced LSP tuned to the emission energy results in a four-fold increase in PL intensity. The localized field due to the resonantly coupled LSP modes induces n-π* transitions that are not observed in the absence of the resonant interaction of the plasmons with the excitons. An increase in the density of the Ag-NPs result in a detuning of the LSP energy from the emission energy of the nanoparticles. The detuning is due to the cumulative effect of the red-shift in the LSP energy and the electrostatic field induced blue shift in the PL energy of the rGO-QDs. The detuning quenches the PL emission from rGO-QDs at higher concentration of Ag NPs due to non-dissipative effects unlike plasmon induced Joule heating that occurs under resonance conditions. An increase in Au nanoparticles concentration results in an enhancement of PL emission due to electrostatic image charge effect.

  17. Competition Between Resonant Plasmonic Coupling and Electrostatic Interaction in Reduced Graphene Oxide Quantum Dots

    PubMed Central

    Karna, Sanjay; Mahat, Meg; Choi, Tae-Youl; Shimada, Ryoko; Wang, Zhiming; Neogi, Arup

    2016-01-01

    The light emission from reduced graphene oxide quantum dots (rGO-QDs) exhibit a significant enhancement in photoluminescence (PL) due to localized surface plasmon (LSP) interactions. Silver and gold nanoparticles (NPs) coupled to rGO nanoparticles exhibit the effect of resonant LSP coupling on the emission processes. Enhancement of the radiative recombination rate in the presence of Ag-NPs induced LSP tuned to the emission energy results in a four-fold increase in PL intensity. The localized field due to the resonantly coupled LSP modes induces n-π* transitions that are not observed in the absence of the resonant interaction of the plasmons with the excitons. An increase in the density of the Ag-NPs result in a detuning of the LSP energy from the emission energy of the nanoparticles. The detuning is due to the cumulative effect of the red-shift in the LSP energy and the electrostatic field induced blue shift in the PL energy of the rGO-QDs. The detuning quenches the PL emission from rGO-QDs at higher concentration of Ag NPs due to non-dissipative effects unlike plasmon induced Joule heating that occurs under resonance conditions. An increase in Au nanoparticles concentration results in an enhancement of PL emission due to electrostatic image charge effect. PMID:27872487

  18. Resonance hybridization and near field properties of strongly coupled plasmonic ring dimer-rod nanosystem

    SciTech Connect

    Koya, Alemayehu Nana; Ji, Boyu; Hao, Zuoqiang; Lin, Jingquan

    2015-09-21

    Combined effects of polarization, split gap, and rod width on the resonance hybridization and near field properties of strongly coupled gold dimer-rod nanosystem are comparatively investigated in the light of the constituent nanostructures. By aligning polarization of the incident light parallel to the long axis of the nanorod, introducing small split gaps to the dimer walls, and varying width of the nanorod, we have simultaneously achieved resonance mode coupling, huge near field enhancement, and prolonged plasmon lifetime. As a result of strong coupling between the nanostructures and due to an intense confinement of near fields at the split and dimer-rod gaps, the extinction spectrum of the coupled nanosystem shows an increase in intensity and blueshift in wavelength. Consequently, the near field lifespan of the split-nanosystem is prolonged in contrast to the constituent nanostructures and unsplit-nanosystem. On the other hand, for polarization of the light perpendicular to the long axis of the nanorod, the effect of split gap on the optical responses of the coupled nanosystem is found to be insignificant compared to the parallel polarization. These findings and such geometries suggest that coupling an array of metallic split-ring dimer with long nanorod can resolve the huge radiative loss problem of plasmonic waveguide. In addition, the Fano-like resonances and immense near field enhancements at the split and dimer-rod gaps imply the potentials of the nanosystem for practical applications in localized surface plasmon resonance spectroscopy and sensing.

  19. Competition Between Resonant Plasmonic Coupling and Electrostatic Interaction in Reduced Graphene Oxide Quantum Dots

    NASA Astrophysics Data System (ADS)

    Karna, Sanjay; Mahat, Meg; Choi, Tae-Youl; Shimada, Ryoko; Wang, Zhiming; Neogi, Arup

    2016-11-01

    The light emission from reduced graphene oxide quantum dots (rGO-QDs) exhibit a significant enhancement in photoluminescence (PL) due to localized surface plasmon (LSP) interactions. Silver and gold nanoparticles (NPs) coupled to rGO nanoparticles exhibit the effect of resonant LSP coupling on the emission processes. Enhancement of the radiative recombination rate in the presence of Ag-NPs induced LSP tuned to the emission energy results in a four-fold increase in PL intensity. The localized field due to the resonantly coupled LSP modes induces n-π* transitions that are not observed in the absence of the resonant interaction of the plasmons with the excitons. An increase in the density of the Ag-NPs result in a detuning of the LSP energy from the emission energy of the nanoparticles. The detuning is due to the cumulative effect of the red-shift in the LSP energy and the electrostatic field induced blue shift in the PL energy of the rGO-QDs. The detuning quenches the PL emission from rGO-QDs at higher concentration of Ag NPs due to non-dissipative effects unlike plasmon induced Joule heating that occurs under resonance conditions. An increase in Au nanoparticles concentration results in an enhancement of PL emission due to electrostatic image charge effect.

  20. Suppression of surface plasmon resonance in Au nanoparticles upon transition to the liquid state.

    PubMed

    Gerasimov, V S; Ershov, A E; Gavrilyuk, A P; Karpov, S V; Ågren, H; Polyutov, S P

    2016-11-14

    Significant suppression of resonant properties of single gold nanoparticles at the surface plasmon frequency during heating and subsequent transition to the liquid state has been demonstrated experimentally and explained for the first time. The results for plasmonic absorption of the nanoparticles have been analyzed by means of Mie theory using experimental values of the optical constants for the liquid and solid metal. The good qualitative agreement between calculated and experimental spectra support the idea that the process of melting is accompanied by an abrupt increase of the relaxation constants, which depends, beside electron-phonon coupling, on electron scattering at a rising number of lattice defects in a particle upon growth of its temperature, and subsequent melting as a major cause for the observed plasmonic suppression. It is emphasized that observed effect is fully reversible and may underlie nonlinear optical responses of nanocolloids and composite materials containing plasmonic nanoparticles and their aggregates in conditions of local heating and in general, manifest itself in a wide range of plasmonics phenomena associated with strong heating of nanoparticles.

  1. Directional thermal emission control by coupling between guided mode resonances and tunable plasmons in multilayered graphene

    NASA Astrophysics Data System (ADS)

    Ito, Kota; Iizuka, Hideo

    2016-10-01

    Directional thermal radiation is attracting interest because of its applicability to thermal management systems and mid-infrared light sources. Plasmons in a single graphene layer are tunable by the chemical potential, while the lateral wavenumber of the plasmon dispersion is too large for the directional coupling to the far field. In this paper, we achieve directional thermal radiation by utilizing tunable plasmons in multilayered graphene. The lateral wavenumber of the plasmon is shown to be reduced as the number of graphene layers increases, and the reduction is analytically explained. The thermally excited graphene plasmon couples to the guided mode resonance in a silicon grating through evanescent waves so as to realize angular-selective far-field emission. We develop a modal analysis in order to investigate the coupling condition. In addition, the directional thermal emission including asymmetric one can be tuned by varying the chemical potential of graphene layers. The calculated emissivity obtained by changing both the chemical potential and the height of the grating suggests the control of the angular heat flux profile.

  2. Multi-resonant plasmonic nanodome arrays for label-free biosensing applications

    NASA Astrophysics Data System (ADS)

    Choi, Charles J.; Semancik, Steve

    2013-08-01

    The characteristics and utility of plasmonic nanodome arrays capable of supporting multiple resonance modes are described. A low-cost, large-area replica molding process is used to produce, on flexible plastic substrates, two-dimensional periodic arrays of cylinders that are subsequently coated with SiO2 and Ag thin films to form dome-shaped structures, with 14 nm spacing between the features, in a precise and reproducible fashion. Three distinct optical resonance modes, a grating diffraction mode and two localized surface plasmon resonance (LSPR) modes, are observed experimentally and confirmed by finite-difference-time-domain (FDTD) modeling which is used to calculate the electromagnetic field distribution of each resonance around the nanodome array structure. Each optical mode is characterized by measuring sensitivity to bulk refractive index changes and to surface effects, which are examined using stacked polyelectrolyte layers. The utility of the plasmonic nanodome array as a functional interface for biosensing applications is demonstrated by performing a bioassay to measure the binding affinity constant between protein A and human immunoglobulin G (IgG) as a model system. The nanoreplica molding process presented in this work allows for simple, inexpensive, high-throughput fabrication of nanoscale plasmonic structures over a large surface area (120 × 120 mm2) without the requirement for high resolution lithography or additional processes such as etching or liftoff. The availability of multiple resonant modes, each with different optical properties, allows the nanodome array surface to address a wide range of biosensing problems with various target analytes of different sizes and configurations.

  3. Surface plasmon resonance induced excellent solar control for VO₂@SiO₂ nanorods-based thermochromic foils.

    PubMed

    Zhou, Yijie; Huang, Aibin; Li, Yamei; Ji, Shidong; Gao, Yanfeng; Jin, Ping

    2013-10-07

    Transition-metal oxide nanocrystals are novel candidates for being used as the hosts of localized surface plasmon resonance because they exhibit fascinating properties arising from the unique characteristics of their outer-d valence electrons. VO₂(M) nanocrystal is well-known due to its reversible metal-insulator transition (MIT) temperature near room temperature (∼68 °C) corresponding to the appearance/disappearance of localized surface plasmon resonance across the MIT. In this study, a microemulsion-based method was introduced to synthesize VO₂(M)@SiO₂ nanoparticles which were applied to prepare VO₂-based thermochromic foils owing to a strong and tunable surface plasmon resonance in the metallic state. The optical transmittance spectra demonstrates that the employment of surface plasmon resonance in VO₂-based thermochromic foils greatly improves their solar regulating efficiency up to 18.54%, and provides an unprecedented insight in optimizing VO₂-based thermochromic windows for solar control.

  4. Wavelength dependent specific plasmon resonance coupling of single silver nanoparticles with EGFP.

    PubMed

    Lee, Kerry J; Huang, Tao; Nallathamby, Prakash D; Xu, Xiao-Hong Nancy

    2015-11-14

    Noble metal nanoparticles (NPs) possess unique plasmonic properties, enabling them to serve as sub-diffraction light sources and nano- antennae for a wide range of applications. Here we report the specific interaction of single Ag NPs with single EGFP molecules and a high dependence of their interaction upon localized-surface-plasmon-resonance (LSPR) spectra of single Ag NPs and EGFP. The LSPR spectra of single red Ag NPs show a stunning 60 nm blue-shift during their incubation with EGFP, whereas they remain unchanged during their incubation with bovine serum albumin (BSA). Interestingly, the peak wavelengths of the LSPR spectra of green and blue Ag NPs remain essentially unchanged during their incubation with either EGFP or BSA. These interesting findings suggest that plasmon-resonance-energy-transfer (PRET) from single Ag NPs to EGFP might follow a two-photon excitation mechanism to excite EGFP and the fluorescence of the excited EGFP might couple with the plasmon of single NPs leading to a blue-shift of the red NPs. These distinctive phenomena are only observed by real-time single NP spectroscopic measurements. This study offers exciting new opportunities to design new sensing and imaging tools with high specificity and sensitivity to study long-range molecular interactions and dynamic events in single live cells, and to probe the underlying molecular mechanisms of PRET.

  5. Wavelength dependent specific plasmon resonance coupling of single silver nanoparticles with EGFP

    NASA Astrophysics Data System (ADS)

    Lee, Kerry J.; Huang, Tao; Nallathamby, Prakash D.; Xu, Xiao-Hong Nancy

    2015-10-01

    Noble metal nanoparticles (NPs) possess unique plasmonic properties, enabling them to serve as sub-diffraction light sources and nano- antennae for a wide range of applications. Here we report the specific interaction of single Ag NPs with single EGFP molecules and a high dependence of their interaction upon localized-surface-plasmon-resonance (LSPR) spectra of single Ag NPs and EGFP. The LSPR spectra of single red Ag NPs show a stunning 60 nm blue-shift during their incubation with EGFP, whereas they remain unchanged during their incubation with bovine serum albumin (BSA). Interestingly, the peak wavelengths of the LSPR spectra of green and blue Ag NPs remain essentially unchanged during their incubation with either EGFP or BSA. These interesting findings suggest that plasmon-resonance-energy-transfer (PRET) from single Ag NPs to EGFP might follow a two-photon excitation mechanism to excite EGFP and the fluorescence of the excited EGFP might couple with the plasmon of single NPs leading to a blue-shift of the red NPs. These distinctive phenomena are only observed by real-time single NP spectroscopic measurements. This study offers exciting new opportunities to design new sensing and imaging tools with high specificity and sensitivity to study long-range molecular interactions and dynamic events in single live cells, and to probe the underlying molecular mechanisms of PRET.

  6. Electron photoemission in plasmonic nanoparticle arrays: analysis of collective resonances and embedding effects

    NASA Astrophysics Data System (ADS)

    Zhukovsky, Sergei V.; Babicheva, Viktoriia E.; Uskov, Alexander V.; Protsenko, Igor E.; Lavrinenko, Andrei V.

    2014-09-01

    We theoretically study the characteristics of photoelectron emission in plasmonic nanoparticle arrays. Nanoparticles are partially embedded in a semiconductor, forming Schottky barriers at metal/semiconductor interfaces through which photoelectrons can tunnel from the nanoparticle into the semiconductor; photodetection in the infrared range, where photon energies are below the semiconductor band gap (insufficient for band-to-band absorption in semiconductor), is therefore possible. The nanoparticles are arranged in a sparse rectangular lattice so that the wavelength of the lattice-induced Rayleigh anomalies can overlap the wavelength of the localized surface plasmon resonance of the individual particles, bringing about collective effects from the nanoparticle array. Using full-wave numerical simulations, we analyze the effects of lattice constant, embedding depth, and refractive index step between the semiconductor layer and an adjacent transparent conductive oxide layer. We show that the presence of refractive index mismatch between media surrounding the nanoparticles disrupts the formation of a narrow absorption peak associated with the Rayleigh anomaly, so the role of collective lattice effects in the formation of plasmonic resonance is diminished. We also show that 5-20 times increase of photoemission can be achieved on embedding of nanoparticles without taking into account dynamics of ballistic electrons. The results obtained can be used to increase efficiency of plasmon-based photodetectors and photovoltaic devices. The results may provide clues to designing an experiment where the contributions of surface and volume photoelectric effects to the overall photocurrent would be defined.

  7. Three-dimensional cavity nanoantennas with resonant-enhanced surface plasmons as dynamic color-tuning reflectors.

    PubMed

    Fan, J R; Wu, W G; Chen, Z J; Zhu, J; Li, J

    2017-03-09

    As plasmonic antennas for surface-plasmon-assisted control of optical fields at specific frequencies, metallic nanostructures have recently emerged as crucial optical components for fascinating plasmonic color engineering. Particularly, plasmonic resonant nanocavities can concentrate lightwave energy to strongly enhance light-matter interactions, making them ideal candidates as optical elements for fine-tuning color displays. Inspired by the color mixing effect found on butterfly wings, a new type of plasmonic, multiresonant, narrow-band (the minimum is about 45 nm), high-reflectance (the maximum is about 95%), and dynamic color-tuning reflector is developed. This is achieved from periodic patterns of plasmonic resonant nanocavities in free-standing capped-pillar nanostructure arrays. Such cavity-coupling structures exhibit multiple narrow-band selective and continuously tunable reflections via plasmon standing-wave resonances. Consequently, they can produce a variety of dark-field vibrant reflective colors with good quality, strong color signal and fine tonal variation at the optical diffraction limit. This proposed multicolor scheme provides an elegant strategy for realizing personalized and customized applications in ultracompact photonic data storage and steganography, colorimetric sensing, 3D holograms and other plasmon-assisted photonic devices.

  8. Surface plasmon resonance scattered by a dielectric sphere

    NASA Astrophysics Data System (ADS)

    Hong, Xin; Yin, Xuejie

    2016-11-01

    It is well known that when total internal reflection occurs at the interface between high to low refractive index, evanescent field will go into the media with low refractive index. This field can be scattered by a small dielectric particle on the surface. In this paper, with the aim to enhance the scattering field we introduced a thin gold film, the filed modified by the metallic film was theoretically calculated by FDTD solver. Further a polystyrene bead at the diameter of 200nm and 800nm was employed to test the model. Theoretical and experimental results agree well with each other that the locally excitated surface plasmon play a dominant role in the field enhancement scattered by the sphere.

  9. Novel multichannel surface plasmon resonance photonic crystal fiber biosensor

    NASA Astrophysics Data System (ADS)

    Hameed, Mohamed Farhat O.; Alrayk, Yassmin K. A.; Shaalan, A. A.; El Deeb, Walid S.; Obayya, S. S. A.

    2016-04-01

    In this paper, a novel design of highly sensitive biosensor based on photonic crystal fiber is presented and analyzed using full vectorial finite element method. The suggested design depends on using silver layer as a plasmonic active material coated by a gold layer to protect silver oxidation. The reported sensor is based on the detection using the quasi transverse electric (TE) and quasi transverse magnetic (TM) modes which offers the possibility of multi-channel/multi-analyte sensing. The sensor geometrical parameters are optimized to achieve high sensitivity for the two polarized modes. High refractive index sensitivity of about 4750 nm/RIU (refractive index unit) and 4300 nm/RIU with corresponding resolutions of 2.1×10-5 RIU, and 2.33×10-5 RIU can be obtained for the quasi TM and quasi TE modes, respectively.

  10. Sensors based on visible collective resonances of plasmonic lattices

    NASA Astrophysics Data System (ADS)

    Sadeghi, Seyed M.; Wing, Waylin J.; Campbell, Quinn

    2016-09-01

    We show arrays of large gold nanodisks on glass substrates can support strong optical features with narrow spectral widths associated with their collective plasmonic-lattice modes. Our results show that these modes can offer significant sensitivity to the refractive index of the environment, far more than those of individual nanodisks. We show the visible collective modes supported by such arrays can distinctively detect a monolayer of biotin with high resolution. We use donor (CdSe/ZnS) and acceptor (CuInS/ZnS) quantum dots to investigate the field properties of these arrays after deposition of a thick layer of a silicon. We demonstrate a distinct increase of emission of CuInS/ZnS quantum dots, indicating the possibility of enhancement of energy transfer between these two types of quantum dots.

  11. Subpicomolar sensing of delta-opioid receptor ligands by molecular-imprinted polymers using plasmon-waveguide resonance spectroscopy.

    PubMed

    Devanathan, Savitha; Salamon, Zdzislaw; Nagar, Anoop; Narang, Subhash; Schleich, Donald; Darman, Paul; Hruby, Victor; Tollin, Gordon

    2005-04-15

    Here we report, for the first time, the formation of a biomimetic covalently imprinted polymeric sensor for a target ligand, the delta-opioid G-protein coupled receptor agonist DPDPE, which reproducibly exhibits subpicomolar binding affinity in an aqueous environment. In addition to having a well-defined and homogeneous binding site, the imprinted polymer template is quite stable to storage in both the dry and wet states and has at least 6 orders of magnitude higher affinities than exhibited by similar peptide-based molecular-imprinted polymers (MIPs) thus far. A highly sensitive optical detection methodology, plasmon-waveguide resonance spectroscopy, was employed, capable of measuring binding in real time and discriminating between ligand molecules, without requiring labeling protocols (fluorophores or radioisotopes). The DPDPE-imprinted polymer showed a broad structure-activity relationship profile, not unlike that found for protein receptors. Such sensitivity and robustness of MIPs suggests potential applications ranging from biowarfare agent detection to pharmaceutical screening.

  12. Polarization-Independent Multiple Fano Resonances in Plasmonic Nonamers for Multimode-Matching Enhanced Multiband Second-Harmonic Generation.

    PubMed

    Liu, Shao-Ding; Leong, Eunice Sok Ping; Li, Guang-Can; Hou, Yidong; Deng, Jie; Teng, Jing Hua; Ong, Hock Chun; Lei, Dang Yuan

    2016-01-26

    Plasmonic oligomers composed of metallic nanoparticles are one class of the most promising platforms for generating Fano resonances with unprecedented optical properties for enhancing various linear and nonlinear optical processes. For efficient generation of second-harmonic emissions at multiple wavelength bands, it is critical to design a plasmonic oligomer concurrently having multiple Fano resonances spectrally matching the fundamental excitation wavelengths and multiple plasmon resonance modes coinciding with the harmonic wavelengths. Thus far, the realization of such a plasmonic oligomer remains a challenge. This study demonstrates both theoretically and experimentally that a plasmonic nonamer consisting of a gold nanocross surrounded by eight nanorods simultaneously sustains multiple polarization-independent Fano resonances in the near-infrared region and several higher-order plasmon resonances in the visible spectrum. Due to coherent amplification of the nonlinear excitation sources by the Fano resonances and efficient scattering-enhanced outcoupling by the higher-order modes, the second-harmonic emission of the nonamer is significantly increased at multiple spectral bands, and their spectral positions and radiation patterns can be flexibly manipulated by easily tuning the length of the surrounding nanorods in the nonamer. These results provide us with important implications for realizing ultrafast multichannel nonlinear optoelectronic devices.

  13. Surface plasmon resonance hydrogen sensor based on metallic grating with high sensitivity.

    PubMed

    Lin, Kaiqun; Lu, Yonghua; Chen, Junxue; Zheng, Rongsheng; Wang, Pei; Ming, Hai

    2008-11-10

    High sensitivity is obtained at larger resonant incident angle if negative diffraction order of metallic grating is used to excite the surface plasmon. A highly sensitive grating-based surface plasmon resonance (SPR) sensor is designed for the hydrogen detection. A thin palladium (Pd) film deposited on the grating surface is used as transducer. The influences of grating period and the thickness of Pd on the performance of sensor are investigated using rigorous coupled-wave analysis (RCWA) method. The sensitivity as well as the width of the SPR curves and reflective amplitude is considered simultaneously for designing the grating-based SPR hydrogen sensor, and a set of optimized structural parameters is presented. The performance of grating-based SPR sensor is also compared with that of conventional prism-based SPR sensor.

  14. Microfluidic Surface Plasmon Resonance Sensors: From Principles to Point-of-Care Applications

    PubMed Central

    Wang, Da-Shin; Fan, Shih-Kang

    2016-01-01

    Surface plasmon resonance (SPR) is a label-free, highly-sensitive, and real-time sensing technique. Conventional SPR sensors, which involve a planar thin gold film, have been widely exploited in biosensing; various miniaturized formats have been devised for portability purposes. Another type of SPR sensor which utilizes localized SPR (LSPR), is based on metal nanostructures with surface plasmon modes at the structural interface. The resonance condition is sensitive to the refractive index change of the local medium. The principles of these two types of SPR sensors are reviewed and their integration with microfluidic platforms is described. Further applications of microfluidic SPR sensors to point-of-care (POC) diagnostics are discussed. PMID:27472340

  15. A new method for measuring wetness of flowing steam based on surface plasmon resonance

    PubMed Central

    2014-01-01

    A novel method for real-time and inline wetness measurement based on surface plasmon resonance (SPR) is presented in this paper. The Kretschmann geometry is adopted to excite surface plasmon waves in our measurement system. In order to prevent water coating, an ultrathin layer of hydrophobic coating is formed on the surface of Au layer. The experimental results show that the level of steam wetness can be obtained via the area ratio of water and air on the prism, which is determined by analyzing the SPR spectrum of wet steam based on a Gaussian model. In addition, during the online measurement of flowing wet steam wetness, significant shifts in the resonant position of the SPR spectrum occurred, which can be attributed to the strong interaction of the adjacent water droplets. PMID:24418483

  16. Multilayered core-satellite nanoassemblies with fine-tunable broadband plasmon resonances.

    PubMed

    Xiong, Wei; Sikdar, Debabrata; Yap, Lim Wei; Premaratne, Malin; Li, Xinyong; Cheng, Wenlong

    2015-02-28

    We report on a robust nanotemplating approach to synthesize plasmonic multilayered core-satellite (MCS) nanoassemblies. Templated with gold nanorods, ultrathin Au/Ag alloy cages and satellite gold nanoparticles can be constructed sequentially by galvanic replacement reactions and electrostatic self-assembly, respectively, forming structurally well-defined MCS. The MCS nanoassemblies exhibit strong broadband plasmon resonances from ∼440 to ∼1100 nm, and their resonant features can be fine-tuned by adjusting the size and number density of satellite nanoparticles and by adjusting the thickness of the silica spacer between cage and satellite particles. Such fine-engineered MCS nanoassemblies enable precise programming of the strength and distribution of "hot spots" to maximize the overall enhancement of surface enhanced Raman scattering.

  17. Microfluidic Devices Integrating Microcavity Surface-Plasmon-Resonance Sensors: Glucose Oxidase Binding-Activity Detection

    PubMed Central

    Amarie, Dragos; Alileche, Abdelkrim; Dragnea, Bogdan; Glazier, James A.

    2010-01-01

    We have developed miniature (≈1 μm diameter) microcavity surface-plasmon-resonance sensors (MSPRS), integrated them with microfluidics and tested their sensitivity to refractive-index changes. We tested their biosensing capability by distinguishing the interaction of glucose oxidase (Mr 160 kDa) with its natural substrate (β-D-glucose, Mr 180 Da) from its interactions with non-specific substrates (L-glucose, D-mannose and 2-deoxy-D-glucose). We ran the identical protocol we had used with the MSPRS on a Biacore 3000 instrument using their bare gold chip. Only the MSPRS was able to detect β-D-glucose binding to glucose oxidase. Each MSPRS can detect the binding to its surface of fewer than 35,000 glucose-oxidase molecules (representing 9.6 fg or 60 zmol of protein), about 106 times fewer than classical surface-plasmon-resonance biosensors. PMID:19968248

  18. Double active control of the plasmonic resonance of a gold nanoparticle array

    NASA Astrophysics Data System (ADS)

    de Sio, Luciano; Cunningham, Alastair; Verrina, Vanessa; Tone, Caterina Maria; Caputo, Roberto; Bürgi, Thomas; Umeton, Cesare

    2012-11-01

    A two-fold active control of the plasmonic resonance of randomly distributed gold nanoparticles (GNPs) has been achieved. GNPs have been immobilized on an Indium Tin Oxide (ITO) coated glass substrate and then covered with a liquid crystalline compound. The system has been investigated by means of atomic force and scanning electron microscopy, revealing the presence of isolated and well distributed GNPs. The application of an external electric field to the sample has a two-fold consequence: the re-orientation of the hybrid-aligned liquid crystal layer and the formation of a carrier accumulation layer in the proximity of the ITO substrate. The refractive indices of both liquid crystal and accumulation layers are influenced by the applied field in a competitive way and produce a ``dancing behavior'' of the GNP's plasmonic resonance spectral position.

  19. Surface plasmon resonance biosensor based on large size square-lattice photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Bing, Pibin; Li, Zhongyang; Yuan, Sheng; Yao, Jianquan; Lu, Ying

    2016-04-01

    A surface plasmon resonance biosensor based on large size square-lattice photonic crystal fiber has been designed and simulated by finite element method. The square-lattice airholes are first coated with a calcium fluoride layer to provide mode confinement, then a nanoscale gold layer is deposited to excite the plasmon mode, and finally, the sample is infiltrated into the holes. The numerical results reveal that the resonance properties are easily affected by many parameters. The refractive index resolution of corresponding sensor can reach 4.3 × 10-6 RIU when the optimum parameters are set as the radius of curvature of the airhole r = 2 μm, the thickness of the core struts c = 200 nm, the auxiliary dielectric layer s = 1 μm, and the gold film d = 40 nm. In addition, the effective area and nonlinear coefficient are calculated.

  20. Microfluidic Surface Plasmon Resonance Sensors: From Principles to Point-of-Care Applications.

    PubMed

    Wang, Da-Shin; Fan, Shih-Kang

    2016-07-27

    Surface plasmon resonance (SPR) is a label-free, highly-sensitive, and real-time sensing technique. Conventional SPR sensors, which involve a planar thin gold film, have been widely exploited in biosensing; various miniaturized formats have been devised for portability purposes. Another type of SPR sensor which utilizes localized SPR (LSPR), is based on metal nanostructures with surface plasmon modes at the structural interface. The resonance condition is sensitive to the refractive index change of the local medium. The principles of these two types of SPR sensors are reviewed and their integration with microfluidic platforms is described. Further applications of microfluidic SPR sensors to point-of-care (POC) diagnostics are discussed.

  1. A polarization-sensitive mid-infrared plasmonic absorber for multi-band resonance

    NASA Astrophysics Data System (ADS)

    Li, Yongqian; Wang, Binbin; Xu, Xiaolun; Su, Lei; Zhou, Zili

    2014-05-01

    The aim of this work is to present a multi-band absorption metamaterials. One dual cross-shape perfect absorber metamaterials (PAMs) was developed to obtain multi-band spectrum at mid-infrared. The PAMs possess three distinct resonant peaks standing independently, which are attributed to the polarization sensitive excitation of plasmonic resonance. The optical parameters retrieved by S-parameters method were investigated, which provides a satisfactory qualitative description of the multiple-band spectra responses. On the other hand, the near-field plasmonic behaviors and redistribution of the electromagnetic field were probed theoretically and numerically into the PAMs structure, which also explains the observed absorption behavior of the PAMs ensemble based upon the microscopic perspective. The multiplex spectrum enables the infrared perfect absorber metamaterials (PAMs) a powerful tool for direct access to vibrational fingerprints of single molecular structure.

  2. Experimental evidence of localized plasmon resonance in composite materials containing single-wall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Shuba, M. V.; Paddubskaya, A. G.; Plyushch, A. O.; Kuzhir, P. P.; Slepyan, G. Ya.; Maksimenko, S. A.; Ksenevich, V. K.; Buka, P.; Seliuta, D.; Kasalynas, I.; Macutkevic, J.; Valusis, G.; Thomsen, C.; Lakhtakia, A.

    2012-04-01

    Experimental proof of localized plasmon resonance was found in thin films containing either single-walled carbon nanotubes (SWNT) or SWNT bundles of different length. All samples were prepared by a simple technique that permitted the selection of different SWNT lengths in different samples without significant differences in electronic properties. Fourier-transform infrared spectroscopy showed that an optical-density peak, the same as a terahertz conductivity peak, shifts to higher frequencies as the SWNT lengths are reduced—in agreement with a similar tendency predicted for the localized plasmon resonance in finite-length SWNTs [Slepyan , Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.81.205423 81, 205423 (2010)].

  3. Dynamically tunable plasmon-induced absorption in resonator-coupled graphene waveguide

    NASA Astrophysics Data System (ADS)

    Wen, Mengting; Wang, Lingling; Zhai, Xiang; Lin, Qi; Xia, Shengxuan

    2016-11-01

    We demonstrate plasmon-induced absorption (PIA) in an ultra-compact graphene waveguide system which is composed of a single graphene sheet with two air cavities side-coupled to a graphene nanoribbon. By designing two coherent optical pathways, the pronounced PIA can be achieved due to the extreme destructive interference between the radiant and subradiant modes supported by the two graphene nanoribbons. The resonant strength shows strong dependence on the coupling distance between the two graphene nanoribbons and the resonance wavelength can be dynamically tuned by varying their Fermi energy. Furthermore, the group delay time up to -0.14 ps can be reached at the PIA window, suggesting unique fast-light feature. In addition, the double PIA phenomenon is also analyzed by introducing another graphene nanoribbon. Our results may pave the way for controlling the transmission of a light signal in the design of ultra-compact plasmonic devices.

  4. Anomalously strong plasmon resonances in aluminium bronze by modification of the electronic density-of-states

    NASA Astrophysics Data System (ADS)

    Shahcheraghi, N.; Keast, V. J.; Gentle, A. R.; Arnold, M. D.; Cortie, M. B.

    2016-10-01

    We use a combination of experimental measurements and density functional theory calculations to show that modification of the band structure of Cu by additions of Al causes an unexpected enhancement of the dielectric properties. The effect is optimized in alloys with Al contents between 10 and 15 at.% and would result in strong localized surface plasmon resonances at suitable wavelengths of light. This result is surprising as, in general, alloying of Cu increases its DC resistivity and would be expected to increase optical loss. The wavelengths for the plasmon resonances in the optimized alloy are significantly blue-shifted relative to those of pure Cu and provide a new material selection option for the range 2.2-2.8 eV.

  5. An implantable fiber-optic surface plasmon resonance glucose sensor based on LPFG

    NASA Astrophysics Data System (ADS)

    Li, Dachao; Zhu, Rui; Wu, Peng; Yang, Jia; Xu, Kexin

    2012-01-01

    Minimally-invasive blood glucose monitoring is a very efficient and important way to control blood glucose level of diabetes. An implantable fiber-optic surface plasmon resonance sensor for minimally-invasive blood glucose monitoring is presented. As the fiber-optic SPR sensor is sensitive to temperature and moreover the human body temperature drift plays a great effect on measurement results when the sensor is implanted in human body, long period fiber grating (LPFG) is utilized for temperature compensation to improve measurement accuracy. The fiber-optic surface plasmon resonance sensor is theoretically analyzed and the parameters such as the length of sensor, diameter of fiber, thickness of Chrome and gold are calculated and simulated. The parameters of LPFG is analyzed and simulated, such as length, period and modulation depth. The structural parameters of the sensor are optimized through the calculation and simulation.

  6. Dielectric Function for Gold in Plasmonics Applications: Size Dependence of Plasmon Resonance Frequencies and Damping Rates for Nanospheres.

    PubMed

    Derkachova, Anastasiya; Kolwas, Krystyna; Demchenko, Iraida

    Realistic representation of the frequency dependence of dielectric function of noble metals has a significant impact on the accuracy of description of their optical properties and farther applications in plasmonics, nanoscience, and nanotechnology. Drude-type models successfully used in describing material properties of silver, for gold are known to be not perfect above the threshold energy at 1.8 eV. We give the improved, simple dielectric function for gold which accounts for the frequency dependence of the interband transitions over 1.8 eV and, in addition, for the finite size effects in gold nanoparticles. On that basis, we provide the improved characterization of the spectral performance of gold nanoparticles. Furthermore, we give the direct size dependence of the resonance frequencies and total damping rates of localized surface plasmons of gold nanoparticles (retardation effects are taken into full account) in diverse dielectric environments. The results are compared to the data obtained experimentally for gold monodisperse colloidal nanospheres, as well with the experimental results of other authors.

  7. Nanofocusing beyond the near-field diffraction limit via plasmonic Fano resonance

    NASA Astrophysics Data System (ADS)

    Song, Maowen; Wang, Changtao; Zhao, Zeyu; Pu, Mingbo; Liu, Ling; Zhang, Wei; Yu, Honglin; Luo, Xiangang

    2016-01-01

    The past decade has witnessed a great deal of optical systems designed for exceeding the Abbe's diffraction limit. Unfortunately, a deep subwavelength spot is obtained at the price of extremely short focal length, which is indeed a near-field diffraction limit that could rarely go beyond in the nanofocusing device. One method to mitigate such a problem is to set up a rapid oscillatory electromagnetic field that converges at the prescribed focus. However, abrupt modulation of phase and amplitude within a small fraction of a wavelength seems to be the main obstacle in the visible regime, aggravated by loss and plasmonic features that come into function. In this paper, we propose a periodically repeated ring-disk complementary structure to break the near-field diffraction limit via plasmonic Fano resonance, originating from the interference between the complex hybrid plasmon resonance and the continuum of propagating waves through the silver film. This plasmonic Fano resonance introduces a π phase jump in the adjacent channels and amplitude modulation to achieve radiationless electromagnetic interference. As a result, deep subwavelength spots as small as 0.0045λ2 at 36 nm above the silver film have been numerically demonstrated. This plate holds promise for nanolithography, subdiffraction imaging and microscopy.The past decade has witnessed a great deal of optical systems designed for exceeding the Abbe's diffraction limit. Unfortunately, a deep subwavelength spot is obtained at the price of extremely short focal length, which is indeed a near-field diffraction limit that could rarely go beyond in the nanofocusing device. One method to mitigate such a problem is to set up a rapid oscillatory electromagnetic field that converges at the prescribed focus. However, abrupt modulation of phase and amplitude within a small fraction of a wavelength seems to be the main obstacle in the visible regime, aggravated by loss and plasmonic features that come into function. In this

  8. Nanotechnology-Based Surface Plasmon Resonance Affinity Biosensors for In Vitro Diagnostics

    PubMed Central

    Antiochia, Riccarda; Bollella, Paolo; Favero, Gabriele

    2016-01-01

    In the last decades, in vitro diagnostic devices (IVDDs) became a very important tool in medicine for an early and correct diagnosis, a proper screening of targeted population, and also assessing the efficiency of a specific therapy. In this review, the most recent developments regarding different configurations of surface plasmon resonance affinity biosensors modified by using several nanostructured materials for in vitro diagnostics are critically discussed. Both assembly and performances of the IVDDs tested in biological samples are reported and compared. PMID:27594884

  9. Refractive index sensing with Fano resonant plasmonic nanostructures: a symmetry based nonlinear approach.

    PubMed

    Butet, Jérémy; Martin, Olivier J F

    2014-12-21

    Sensing using surface plasmon resonances is one of the most promising practical applications of plasmonic nanostructures and Fano resonances allow achieving a lower detection limit thanks to their narrow spectral features. However, a narrow spectral width of the subradiant mode in a plasmonic system, as observed in the weak coupling regime, is in general associated with a low modulation of the complete spectral response. In this article, we show that this limitation can be overcome by a nonlinear approach based on second harmonic generation and its dependence on symmetry at the nanoscale. The Fano resonant systems considered in this work are gold nanodolmens. Their linear and nonlinear responses are evaluated using a surface integral equation method. The numerical results demonstrate that a variation of the refractive index of the surrounding medium modifies the coupling between the dark and bright modes, resulting in a modification of the electromagnetic wave scattered at the second harmonic wavelength, especially the symmetry of the nonlinear emission. Reciprocally, we show that evaluating the asymmetry of the nonlinear emission provides a direct measurement of the gold nanodolmens dielectric environment. Interestingly, the influence of the refractive index of the surrounding medium on the nonlinear asymmetry parameter is approximately 10 times stronger than on the spectral position of the surface plasmon resonance: hence, smaller refractive index changes can be detected with this new approach. Practical details for an experimental realization of this sensing scheme are discussed and the resolution is estimated to be as low as Δn = 1.5 × 10(-3), respectively 1.5 × 10(-5), for an acquisition time of 60 s for an isolated gold nanodolmen, respectively an array of 10 × 10 nanodolmens.

  10. Development of a Surface Plasmon Resonance n-dodecane Vapor Sensor

    PubMed Central

    Aguirre, Narcizo Muñoz; Pérez, Lilia Martínez; Colín, Jose Alfredo; Buenrostro-Gonzalez, Eduardo

    2007-01-01

    Using a high density polyethylene thin film over gold layer, a Surface Plasmon Resonance sensor for detecting n-dodecane vapor is developed. Preliminary results will be presented, showing that samples in the range of a few hundred ppm(V) of n-dodecane vapor in butane gas can be sensed. Also, studying the response as a function of time, it is demonstrated that the sensing process is quickly reversible.

  11. Self-calibrated dynamical optical biochip system using surface plasmon resonance imaging: application to genotyping

    NASA Astrophysics Data System (ADS)

    Hottin, Jérôme; Moreau, Julien; Spadavecchia, Jolanda; Bellemain, Alain; Lecerf, Laure; Goossens, Michel; Canva, Michael

    2008-04-01

    The present paper summarizes some of our work in the field of genetic diagnosis using Surface Plasmon Resonance Imaging. The optical setup and its capability are presented, as well as the gold surface functionalization used. Results obtained with oligonucleotides targets, specific to Cystic Fibrosis disease, in high and low concentration are shown. The self-calibration method we have developed to reduce data dispersion in genetic diagnosis applications is described.

  12. Localized Surface Plasmon Resonance as a Biosensing Platform for Developing Countries

    PubMed Central

    Hammond, Jules L.; Bhalla, Nikhil; Rafiee, Sarah D.; Estrela, Pedro

    2014-01-01

    The discovery of the phenomena known as localized surface plasmon resonance (LSPR) has provided the basis for many research areas, ranging from materials science to biosensing. LSPR has since been viewed as a transduction platform that could yield affordable, portable devices for a multitude of applications. This review aims to outline the potential applications within developing countries and the challenges that are likely to be faced before the technology can be effectively employed. PMID:25587417

  13. Cavitands: Container Molecules for Surface Plasmon Resonance (SPR)-Based Chemical Vapor Detection

    DTIC Science & Technology

    2005-01-01

    spin coated onto surface plasmon resonance substrates (50-nm thick gold-coated cover glass). Spin coating was performed at 4000 rpm for 60 s at...room temperature. Th e spin coating parameters gave a fi lm thickness (confi rmed using spectroscopic ellipsometry) of nearly 4 nm. For targets, a...fact that the polymer fi lms were about twice as thick as the cavitand fi lms obtained under identical spin - coating conditions. Th is clearly

  14. Long-wave approximation for hybridization modeling of local surface plasmonic resonance in nanoshells.

    PubMed

    Li, Ben Q; Liu, Changhong

    2011-01-15

    A hybridization model for the localized surface plasmon resonance of a nanoshell is developed within the framework of long-wave approximation. Compared with the existing hybridization model derived from the hydrodynamic simulation of free electron gas, this approach is much simpler and gives identical results for a concentric nanoshell. Also, with this approach, the limitations associated with the original hybridization model are succinctly stated. Extension of this approach to hybridization modeling of more complicated structures such as multiplayered nanoshells is straightforward.

  15. Reference-compensated surface plasmon resonance biosensor for detection of foodborne pathogens

    NASA Astrophysics Data System (ADS)

    Homola, Jiri; Dostalek, Jakub; Chen, Shengfu; Rasooly, Avraham; Jiang, Shaoyi; Yee, Sinclair S.

    2001-05-01

    We present a dual-channel surface plasmon resonance (SPR) biosensor and demonstrate its applicability to detection of foodborne pathogens such as Staphylococcal enterotoxin B (SEB). Experimental results indicate that the SPR biosensor can detect SEB at very low concentrations: 5 ng/ml in pure samples directly, 0.5 ng/ml in both pure samples and in milk using a sandwich assay.

  16. Multilayered core-satellite nanoassemblies with fine-tunable broadband plasmon resonances

    NASA Astrophysics Data System (ADS)

    Xiong, Wei; Sikdar, Debabrata; Yap, Lim Wei; Premaratne, Malin; Li, Xinyong; Cheng, Wenlong

    2015-02-01

    We report on a robust nanotemplating approach to synthesize plasmonic multilayered core-satellite (MCS) nanoassemblies. Templated with gold nanorods, ultrathin Au/Ag alloy cages and satellite gold nanoparticles can be constructed sequentially by galvanic replacement reactions and electrostatic self-assembly, respectively, forming structurally well-defined MCS. The MCS nanoassemblies exhibit strong broadband plasmon resonances from ~440 to ~1100 nm, and their resonant features can be fine-tuned by adjusting the size and number density of satellite nanoparticles and by adjusting the thickness of the silica spacer between cage and satellite particles. Such fine-engineered MCS nanoassemblies enable precise programming of the strength and distribution of ``hot spots'' to maximize the overall enhancement of surface enhanced Raman scattering.We report on a robust nanotemplating approach to synthesize plasmonic multilayered core-satellite (MCS) nanoassemblies. Templated with gold nanorods, ultrathin Au/Ag alloy cages and satellite gold nanoparticles can be constructed sequentially by galvanic replacement reactions and electrostatic self-assembly, respectively, forming structurally well-defined MCS. The MCS nanoassemblies exhibit strong broadband plasmon resonances from ~440 to ~1100 nm, and their resonant features can be fine-tuned by adjusting the size and number density of satellite nanoparticles and by adjusting the thickness of the silica spacer between cage and satellite particles. Such fine-engineered MCS nanoassemblies enable precise programming of the strength and distribution of ``hot spots'' to maximize the overall enhancement of surface enhanced Raman scattering. Electronic supplementary information (ESI) available: A method for preparing CGNRs and AuNPs. EDX mapping and UV-vis spectra for silica coated CGNR. A model for simulation and an additional E-field for MCS nanoassemblies. See DOI: 10.1039/c4nr06756h

  17. Surface plasmon enhanced interfacial electron transfer and resonance Raman, surface-enhanced resonance Raman studies of cytochrome C mutants

    SciTech Connect

    Zheng, Junwei

    1999-11-08

    Surface plasmon resonance was utilized to enhance the electron transfer at silver/solution interfaces. Photoelectrochemical reductions of nitrite, nitrate, and CO2 were studied on electrochemically roughened silver electrode surfaces. The dependence of the photocurrent on photon energy, applied potential and concentration of nitrite demonstrates that the photoelectrochemical reduction proceeds via photoemission process followed by the capture of hydrated electrons. The excitation of plasmon resonances in nanosized metal structures resulted in the enhancement of the photoemission process. In the case of photoelectrocatalytic reduction of CO2, large photoelectrocatalytic effect for the reduction of CO2 was observed in the presence of surface adsorbed methylviologen, which functions as a mediator for the photoexcited electron transfer from silver metal to CO2 in solution. Photoinduced reduction of microperoxidase-11 adsorbed on roughened silver electrode was also observed and attributed to the direct photoejection of free electrons of silver metal. Surface plasmon assisted electron transfer at nanostructured silver particle surfaces was further determined by EPR method.

  18. Plasmon resonances in linear noble-metal chains

    NASA Astrophysics Data System (ADS)

    Gao, Bin; Ruud, Kenneth; Luo, Yi

    2012-11-01

    The electronic excitations of three noble-metall chains—copper, silver, and gold—have been investigated at the time-dependent density functional theory level. The reduced single-electron density matrix is propagated according to the Liouville-von Neumann equation in the real-time domain after an impulse excitation. The propagation in the real-time domain enables us to investigate the formation and size evolution of electronic excitations in these metallic chains with different number of atoms, up to a total of 26 atoms. The longitudinal oscillations at lower excitation energies are dominated by s → p transitions in these chains and have collective or central resonances, while the first peak involving d → p transitions in the longitudinal mode appears at a higher excitation energy and shows collective resonances. In the transverse oscillations, there are in most cases d → p transitions in each resonance, which can be attributed to either central or end resonances. Convergence of the oscillations, in particular those involving the collective and central resonances in the three noble-metal chains can only be observed for chains with 18 atoms or more. Different spectroscopic characteristics among these three metallic chains can be attributed to their different electronic structures, in particular the relativistic effects in the gold chains have a dramatic effect on their electronic structures and excitations.

  19. Magneto-optical plasmonic heterostructure with ultranarrow resonance for sensing applications

    PubMed Central

    Ignatyeva, Daria O.; Knyazev, Grigory A.; Kapralov, Pavel O.; Dietler, Giovanni; Sekatskii, Sergey K.; Belotelov, Vladimir I.

    2016-01-01

    Currently, sensors invade into our everyday life to bring higher life standards, excellent medical diagnostic and efficient security. Plasmonic biosensors demonstrate an outstanding performance ranking themselves among best candidates for different applications. However, their sensitivity is still limited that prevents further expansion. Here we present a novel concept of magnetoplasmonic sensor with ultranarrow resonances and high sensitivity. Our approach is based on the combination of a specially designed one-dimensional photonic crystal and a ferromagnetic layer to realize ultralong-range propagating magnetoplasmons and to detect alteration of the environment refractive index via observation of the modifications in the Transversal Magnetooptical Kerr Effect spectrum. The fabrication of such a structure is relatively easy in comparison with e.g. nanopatterned samples. The fabricated heterostructure shows extremely sharp (angular width of 0.06°) surface plasmon resonance and even sharper magnetoplasmonic resonance (angular width is 0.02°). It corresponds to the propagation length as large as 106 μm which is record for magnetoplasmons and promising for magneto-optical interferometry and plasmonic circuitry as well as magnetic field sensing. The magnitude of the Kerr effect of 11% is achieved which allows for detection limit of 1∙10−6. The prospects of further increase of the sensitivity of this approach are discussed. PMID:27306301

  20. Surface plasmon resonance biosensors for highly sensitive detection in real samples

    NASA Astrophysics Data System (ADS)

    Sepúlveda, B.; Carrascosa, L. G.; Regatos, D.; Otte, M. A.; Fariña, D.; Lechuga, L. M.

    2009-08-01

    In this work we summarize the main results obtained with the portable surface plasmon resonance (SPR) device developed in our group (commercialised by SENSIA, SL, Spain), highlighting its applicability for the real-time detection of extremely low concentrations of toxic pesticides in environmental water samples. In addition, we show applications in clinical diagnosis as, on the one hand, the real-time and label-free detection of DNA hybridization and single point mutations at the gene BRCA-1, related to the predisposition in women to develop an inherited breast cancer and, on the other hand, the analysis of protein biomarkers in biological samples (urine, serum) for early detection of diseases. Despite the large number of applications already proven, the SPR technology has two main drawbacks: (i) not enough sensitivity for some specific applications (where pM-fM or single-molecule detection are needed) (ii) low multiplexing capabilities. In order solve such drawbacks, we work in several alternative configurations as the Magneto-optical Surface Plasmon Resonance sensor (MOSPR) based on a combination of magnetooptical and ferromagnetic materials, to improve the SPR sensitivity, or the Localized Surface Plasmon Resonance (LSPR) based on nanostructures (nanoparticles, nanoholes,...), for higher multiplexing capabilities.

  1. Active multiple plasmon-induced transparencies with detuned asymmetric multi-rectangle resonators

    NASA Astrophysics Data System (ADS)

    Liu, Dongdong; Wang, Jicheng; Lu, Jian

    2016-11-01

    The phenomenon of plasmon-induced transparency (PIT) is realized in surface plasmon polariton waveguide at the visible and near-infrared ranges. By adding one and two resonant cavities, the PIT peak(s) was (were) achieved due to destructive interference between the side-coupled rectangle cavity and the bus waveguide. The proposed structures were demonstrated by the finite element method. The simulation results showed that for three rectangle resonators system, not only can we manipulate each single PIT window, but also the double PIT windows simultaneously by adjusting one of the geometrical parameters of the system; for four rectangle resonators system, by changing the widths, the lengths and the refractive index of three cavities simultaneously, we would realize treble PIT peaks and induce an off-to-on PIT optical response. Our novel plasmonic structures and the findings pave the way for new design and engineering of highly integrated optical circuit such as nanoscale optical switching, nanosensor and wavelength-selecting nanostructure.

  2. Plasmon resonances of Ag(001) and Ag(111) studied by power density absorption and photoyield

    NASA Astrophysics Data System (ADS)

    Raseev, Georges

    2013-09-01

    This paper models the surface and bulk plasmon resonances in photoabsorption and photoelectron spectra (PES) of the Ag(001) and the Ag(111) surfaces in the region of 2.8-10 eV excited with a p or transverse magnetic linearly polarized laser incident at 45°. Using the recently developed vector potential from electron density-coupled integro-differential equations (VPED-CIDE, [1,2]) model, we calculate the electron escaping probability from the power density absorption, Feibelman's parameter d⊥, the reflectance and the Fermi PE cross section. In the PES experiment the work function is lowered from 4.5 to 2.8 eV by adsorption of sodium. In our model, this lowering is introduced by adding a phenomenological term to the DFT-LDA model potential of Chulkov et al. [3]. For both Ag(001) and Ag(111), the calculated observables display two plasmon resonances, the multipole surface at 3.70 eV and the bulk at 3.90 eV, in fair agreement with the experimental PES of Barman et al. [4,5] and the reflectance. Except for the Fermi PE cross section of Ag(001) which does not display the multipole surface plasmon resonance at 3.70 eV. This poor result is probably due to a poor calculation of the conduction band wave functions obtained from the Schrödinger equation using the modified DFT-LDA model potential of Chulkov et al.

  3. Surface plasmon resonance label-free monitoring of antibody antigen interactions in real time

    SciTech Connect

    Kausaite, A.; van Dijk, M.; Castrop, J.; Ramanaviciene, A.; Baltrus, J.P.; Acaite, J.; Ramanavicius, A.

    2007-01-01

    Detection of biologically active compounds is one of the most important topics in molecular biology and biochemistry. One of the most promising detection methods is based on the application of surface plasmon resonance for label-free detection of biologically active compounds. This method allows one to monitor binding events in real time without labeling. The system can therefore be used to determine both affinity and rate constants for interactions between various types of molecules. Here, we describe the application of a surface plasmon resonance biosensor for label-free investigation of the interaction between an immobilized antigen bovine serum albumin (BSA) and antibody rabbit anti-cow albumin IgG1 (anti-BSA). The formation of a self-assembled monolayer (SAM) over a gold surface is introduced into this laboratory training protocol as an effective immobilization method, which is very promising in biosensing systems based on detection of affinity interactions. In the next step, covalent attachment via artificially formed amide bonds is applied for the immobilization of proteins on the formed SAM surface. These experiments provide suitable experience for postgraduate students to help them understand immobilization of biologically active materials via SAMs, fundamentals of surface plasmon resonance biosensor applications, and determination of non-covalent biomolecular interactions. The experiment is designed for master and/or Ph.D. students. In some particular cases, this protocol might be adoptable for bachelor students that already have completed an extended biochemistry program that included a background in immunology.

  4. Plasmon resonance in new AsSb–AlGaAs metal–semiconductor metamaterials

    SciTech Connect

    Ushanov, V. I. Chaldyshev, V. V. Bert, N. A.; Nevedomsky, V. N.; Il’inskaya, N. D.; Lebedeva, N. M.; Preobrazhenskii, V. V.; Putyato, M. A.; Semyagin, B. R.

    2015-12-15

    Optical extinction in a metal–semiconductor metamaterial based on a AlGaAs matrix, which contains random arrays of AsSb plasmon nanoinclusions, is studied. The metamaterial is grown by molecular beam epitaxy at a low temperature. A system of nanoinclusions of various sizes is formed by annealing at temperatures 400, 500, and 600°C. Investigation of the sample’s microstructure by transmission electron microscopy shows that the average size of nanoinclusions at the used annealing temperatures is 4–7, 5–8, and 6–9 nm, respectively. It is shown experimentally that AsSb nanoparticle arrays in the AlGaAs matrix cause the resonant absorption of light. It is established that the plasmon-resonance parameters found in the metamaterial are almost independent of the sizes of the AsSb nanoinclusions. The plasmon-resonance energy is (1.47 ± 0.01) eV, while its full width at half maximum is (0.19 ± 0.01) eV.

  5. Colorimetric determination of Timolol concentration based on localized surface plasmon resonance of silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Amirjani, Amirmostafa; Bagheri, Mozhgan; Heydari, Mojgan; Hesaraki, Saeed

    2016-09-01

    In this work, a rapid and simple colorimetric method based on the surface plasmon resonance of silver nanoparticles (AgNPs) was developed for the detection of the drug Timolol. The method used is based on the interaction of Timolol with the surface of the as-synthesized AgNPs, which promotes aggregation of the nanoparticles. This aggregation exploits the surface plasmon resonance through the electric dipole-dipole interaction and coupling among the agglomerated particles, hence bringing forth distinctive changes in the spectra as well as the color of colloidal silver. UV-vis spectrophotometery was used to monitor the changes of the localized surface plasmon resonance of AgNPs at wavelengths of 400 and 550 nm. The developed colorimetric sensor has a wide dynamic range of 1.0 × 10-7 M-1.0 × 10-3 M for detection of Timolol with a low detection limit of 1.2 × 10-6 M. The proposed method was successfully applied for the determination of Timolol concentration in ophthalmic eye-drop solution with a response time lower than 40 s.

  6. Magneto-optical plasmonic heterostructure with ultranarrow resonance for sensing applications

    NASA Astrophysics Data System (ADS)

    Ignatyeva, Daria O.; Knyazev, Grigory A.; Kapralov, Pavel O.; Dietler, Giovanni; Sekatskii, Sergey K.; Belotelov, Vladimir I.

    2016-06-01

    Currently, sensors invade into our everyday life to bring higher life standards, excellent medical diagnostic and efficient security. Plasmonic biosensors demonstrate an outstanding performance ranking themselves among best candidates for different applications. However, their sensitivity is still limited that prevents further expansion. Here we present a novel concept of magnetoplasmonic sensor with ultranarrow resonances and high sensitivity. Our approach is based on the combination of a specially designed one-dimensional photonic crystal and a ferromagnetic layer to realize ultralong-range propagating magnetoplasmons and to detect alteration of the environment refractive index via observation of the modifications in the Transversal Magnetooptical Kerr Effect spectrum. The fabrication of such a structure is relatively easy in comparison with e.g. nanopatterned samples. The fabricated heterostructure shows extremely sharp (angular width of 0.06°) surface plasmon resonance and even sharper magnetoplasmonic resonance (angular width is 0.02°). It corresponds to the propagation length as large as 106 μm which is record for magnetoplasmons and promising for magneto-optical interferometry and plasmonic circuitry as well as magnetic field sensing. The magnitude of the Kerr effect of 11% is achieved which allows for detection limit of 1•10-6. The prospects of further increase of the sensitivity of this approach are discussed.

  7. [Spectra modulated surface plasmon resonance sensor based on side polished multi-mode optical fiber].

    PubMed

    Luo, Yun-Han; Chen, Xiao-Long; Xu, Meng-Yun; Ge, Jia; Zhang, Yi-Long; He, Yong-Hong; Tang, Jie-Yuan; Yu, Jian-Hui; Zhang, Jun; Chen, Zhe; Chen, Xing-Dan

    2014-03-01

    Surface plasmon resonance, which utilizes the resonance of optical evanescent wave with the metal surface plasmon wave, has been developed into a high sensitivity, rapid, label-less measurement method for chemical and biological analysis. In order to improve the spectral sensitivity in refractive index for a side polished fiber surface plasmon resonance sensor, the whole cladding layer and part of core of a multimode fiber was polished off. Additionally, an extra chrome layer with relatively high refractive index was coated on the polished zone before a gold film. The results showed that the sensor can measure the refractive index range from 1.333 to 1. 431 RIU, with the average spectral sensitivity of 4.11 x 10(3) nm RIU(-1), which is better than the reported results. Especially, in the refractive index range of 1. 417 1. 431 RIU, the sensitivity reaches to 1.09 x 10(4) nm RIU(-1). The minimum resolution of approximately 3.6 x 10(-5) RIU was estimated by a combination analysis with the sensor sensitivity and stability. The superiorities possessed by the proposed sensor in high sensitivity, wide detection range, small size and good stability and reproducibility, etc., make it a good candidate for food testing, environmental monitoring, biomedical testing and other related fields.

  8. Fano resonance in graphene-MoS2 heterostructure-based surface plasmon resonance biosensor and its potential applications

    NASA Astrophysics Data System (ADS)

    Zheng, Gaige; Zou, Xiujuan; Chen, Yunyun; Xu, Linhua; Rao, Weifeng

    2017-04-01

    We propose a new configuration of surface plasmon resonance (SPR) sensor that is based on graphene-MoS2 hybrid structures for ultrasensitive detection of molecules. The present configuration is consisted of chalcogenide glass (2S2G) prism, Ag, coupling layer, guiding layer, graphene-MoS2 heterostructure and analyte. We perform numerical and analytical study of the impact of the thickness and refractive index (RI) of the coupling and guiding layer in a planar sensing structure within the Kretschmann configuration on the resonance properties of the excitation. Results of reflectivity calculations clearly demonstrate the sharp Fano-type resonance appears in the curve of SPR because of the coupling between surface plasmon polariton (SPP) and planar waveguide (PWG) modes. The properties of the Fano resonance (FR) strongly depend on the parameters of the structure. The calculated magnetic field profiles manifest that the hybrid nature of the electromagnetic (EM) modes excited in the present structure. The proposed system displays an enhancement factor of sensitivity by intensity more than 2 × 103-fold when compared to the SPR sensing scheme.

  9. Sub-wavelength Unidirectional Antenna Realized by Stacked Spoof Localized Surface Plasmon Resonators

    PubMed Central

    Qin, Feifei; Zhang, Qiang; Xiao, Jun-Jun

    2016-01-01

    The use of resonant structures to control scattering strength and directionality is of importance in various electromagnetic systems. Here we propose and demonstrate sub-wavelength unidirectional scattering by two nearby spoof localized surface plasmon resonators for microwave. The principle is that metal surfaces corrugated by grooves can support magnetic dipolar modes, as well as electric dipolar modes. The resonance is essentially dictated by the geometric parameter of the structure, enabling extremely high degrees of freedom for tuning the scattering properties of the resonator. Particularly, by adjusting the thickness of the resonators, we can make the magnetic dipole mode of one resonator have nearly the same resonant frequency with that of the electric dipole mode of the other resonator. We show that nearly zero backscattering happens when the distance between the two resonators is subwavelenght but larger than a certain value, otherwise strong vertical coupling and mode splitting occur. The results can be extended to other frequency bands and might find application in unique resonant devices as a radio frequency (RF) antenna, filter and metasurface. PMID:27405356

  10. Sub-wavelength Unidirectional Antenna Realized by Stacked Spoof Localized Surface Plasmon Resonators

    NASA Astrophysics Data System (ADS)

    Qin, Feifei; Zhang, Qiang; Xiao, Jun-Jun

    2016-07-01

    The use of resonant structures to control scattering strength and directionality is of importance in various electromagnetic systems. Here we propose and demonstrate sub-wavelength unidirectional scattering by two nearby spoof localized surface plasmon resonators for microwave. The principle is that metal surfaces corrugated by grooves can support magnetic dipolar modes, as well as electric dipolar modes. The resonance is essentially dictated by the geometric parameter of the structure, enabling extremely high degrees of freedom for tuning the scattering properties of the resonator. Particularly, by adjusting the thickness of the resonators, we can make the magnetic dipole mode of one resonator have nearly the same resonant frequency with that of the electric dipole mode of the other resonator. We show that nearly zero backscattering happens when the distance between the two resonators is subwavelenght but larger than a certain value, otherwise strong vertical coupling and mode splitting occur. The results can be extended to other frequency bands and might find application in unique resonant devices as a radio frequency (RF) antenna, filter and metasurface.

  11. Sub-wavelength Unidirectional Antenna Realized by Stacked Spoof Localized Surface Plasmon Resonators.

    PubMed

    Qin, Feifei; Zhang, Qiang; Xiao, Jun-Jun

    2016-07-13

    The use of resonant structures to control scattering strength and directionality is of importance in various electromagnetic systems. Here we propose and demonstrate sub-wavelength unidirectional scattering by two nearby spoof localized surface plasmon resonators for microwave. The principle is that metal surfaces corrugated by grooves can support magnetic dipolar modes, as well as electric dipolar modes. The resonance is essentially dictated by the geometric parameter of the structure, enabling extremely high degrees of freedom for tuning the scattering properties of the resonator. Particularly, by adjusting the thickness of the resonators, we can make the magnetic dipole mode of one resonator have nearly the same resonant frequency with that of the electric dipole mode of the other resonator. We show that nearly zero backscattering happens when the distance between the two resonators is subwavelenght but larger than a certain value, otherwise strong vertical coupling and mode splitting occur. The results can be extended to other frequency bands and might find application in unique resonant devices as a radio frequency (RF) antenna, filter and metasurface.

  12. Surface plasmon resonance biosensing: Approaches for screening and characterising antibodies for food diagnostics.

    PubMed

    Yakes, B J; Buijs, J; Elliott, C T; Campbell, K

    2016-08-15

    Research in biosensing approaches as alternative techniques for food diagnostics for the detection of chemical contaminants and foodborne pathogens has increased over the last twenty years. The key component of such tests is the biorecognition element whereby polyclonal or monoclonal antibodies still dominate the market. Traditionally the screening of sera or cell culture media for the selection of polyclonal or monoclonal candidate antibodies respectively has been performed by enzyme immunoassays. For niche toxin compounds, enzyme immunoassays can be expensive and/or prohibitive methodologies for antibody production due to limitations in toxin supply for conjugate production. Automated, self-regenerating, chip-based biosensors proven in food diagnostics may be utilised as rapid screening tools for antibody candidate selection. This work describes the use of both single channel and multi-channel surface plasmon resonance (SPR) biosensors for the selection and characterisation of antibodies, and their evaluation in shellfish tissue as standard techniques for the detection of domoic acid, as a model toxin compound. The key advantages in the use of these biosensor techniques for screening hybridomas in monoclonal antibody production were the real time observation of molecular interaction and rapid turnaround time in analysis compared to enzyme immunoassays. The multichannel prototype instrument was superior with 96 analyses completed in 2h compared to 12h for the single channel and over 24h for the ELISA immunoassay. Antibodies of high sensitivity, IC50's ranging from 4.8 to 6.9ng/mL for monoclonal and 2.3-6.0ng/mL for polyclonal, for the detection of domoic acid in a 1min analysis time were selected. Although there is a progression for biosensor technology towards low cost, multiplexed portable diagnostics for the food industry, there remains a place for laboratory-based SPR instrumentation for antibody development for food diagnostics as shown herein.

  13. Mass effect of redox reactions: A novel mode for surface plasmon resonance-based bioanalysis.

    PubMed

    Yuan, Pei-Xin; Deng, Sheng-Yuan; Xin, Peng; Ji, Xu-Bo; Shan, Dan; Cosnier, Serge

    2015-12-15

    The pursuit of more specific and sensitive response is a perpetual goal for modern bioassays. This work proposed a novel label-free strategy about redox-related mass effect based on the surface plasmon resonance (SPR) technique for ultrasensitive determination of DNA. The protocol starts with the modification of SPR gilded disk with the capture DNA (cDNA). After the conjugation of immobilized cDNA with the target DNA (tDNA), the hybridization chain reaction was triggered by the introduction of mutual partial complementary primers to elongate the terminal into a nanoscale duplex. As it is reported that porphyrin could intercalate into the grooves of the double-stranded DNA (dsDNA) scaffold, multiple positive-charged Fe(III)meso-tetra(N-methyl-4-pyridyl) porphine (FeTMPyP) with symmetric structure were uptaken for in situ formation of porphyrin-dsDNA complex. Given FeTMPyP a highly efficient catalysis for the peroxide reduction, its presence as a biomimetic cofactor was validated via circular dichroism and UV-vis spectroscopy, demonstrating a tight binding as well as high catalytic activity and stability. Using 4-chloro-1-naphthol as a proton donor, the catalytic reduction of H2O2 would oxidize it into insoluble benzo-4-chloro-hexadienone, which simultaneously deposited on the heterogeneous interface, leading to a significant amplification in both SPR response and topological height profile. The signal increment was proportional to the concentration of tDNA, thus an ultrasensitive SPR-based DNA assay was developed with a linear range over four orders of magnitudes and a sub-femtomolar detection limit of 0.73 fM. The developed methodology exemplifies a different way of thinking about mass-sensing modes, extending conventional SPR-based DNA analysis to relevant biomedical applications.

  14. Plasmon resonance and perfect light absorption in subwavelength trench arrays etched in gallium-doped zinc oxide film

    SciTech Connect

    Hendrickson, Joshua R. Leedy, Kevin; Cleary, Justin W.; Vangala, Shivashankar; Nader, Nima; Guo, Junpeng

    2015-11-09

    Near-perfect light absorption in subwavelength trench arrays etched in highly conductive gallium-doped zinc oxide films was experimentally observed in the mid infrared regime. At wavelengths corresponding to the resonant excitation of surface plasmons, up to 99% of impinging light is efficiently trapped and absorbed in the periodic trenches. Scattering cross sectional calculations reveal that each individual trench acts like a vertical split ring resonator with a broad plasmon resonance spectrum. The coupling of these individual plasmon resonators in the grating structure leads to enhanced photon absorption and significant resonant spectral linewidth narrowing. Ellipsometry measurements taken before and after device fabrication result in different permittivity values for the doped zinc oxide material, indicating that localized annealing occurred during the plasma etching process due to surface heating. Simulations, which incorporate a 50 nm annealed region at the zinc oxide surface, are in a good agreement with the experimental results.

  15. Generating and manipulating higher order Fano resonances in dual-disk ring plasmonic nanostructures.

    PubMed

    Fu, Yuan Hsing; Zhang, Jing Bo; Yu, Ye Feng; Luk'yanchuk, Boris

    2012-06-26

    In this article, we investigate higher order (quadrupolar, octupolar, hexadecapolar, and triakontadipolar) Fano resonances generated in disk ring (DR) silver plasmonic nanostructures. We find that the higher order Fano resonances are generated when the size of the disk is reduced and falls into a certain range. With dual-disk ring (DDR) nanostructures, a rich set of tunable Fano line shapes is provided. More specifically, we report our observations on the optical behavior of the DDRs including asymmetric cases either in two disks with different sizes or their asymmetric locations inside the ring. In the case of symmetric dual-disk ring (SDDR) nanostructures, we demonstrate that the quadrupolar and the hexadecapolar Fano resonances are suppressed, which can reduce the cross-talk in spectroscopic measurements, while the octupolar and the triakontadipolar Fano resonances are enhanced. The potential of using the studied plasmonic nanostructures as biochemical sensors is evaluated with the figure of merit (FOM) and the contrast ratio (CR). The values of the FOM and the CR achieved using the triakontadipolar Fano resonance in the SDDR are 17 and 57%, respectively. These results indicate that the SDDRs could be developed into a high-performance biochemical sensor in the visible wavelength range.

  16. Intrinsic fiber optical gas sensor based on surface plasmon resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Niggemann, Matthias; Katerkamp, Andreas; Pellmann, Maria; Bolsmann, Peter; Reinbold, Joerg; Cammann, Karl

    1995-09-01

    A miniaturized fiber optical sensor based on surface plasmon resonance spectroscopy is investigated in view of the detection of organic solvent vapors, particularly tetrachloroethene. Surface plasmons are excited on a silver coated multimode fiber by polychromatic light, and the resonant excitation is detected as a resonant absorption band in the measured output spectrum. When the analyte is absorbed in a thin gas-sensitive polysiloxane film deposited on the silver layer the polymer film changes its thickness and its refractive index. These changes result in a wavelength shift of the resonant curve depending on the analyte gas concentration. Theoretical considerations about the sensing effect are made and resonance curves were computer-simulated. Based on this simulation the layout of all sensor parameters was optimized. The sensor shows an excellent response to tetrachloroethene with a response time of two seconds and high reporducibility. Using self-assembling monolayers on the silver surface a long-term stability of more than three months is obtained. The sensor shows low cross sensitivities less than 1% to other solvent vapors like aceton and ethanol, furthermore, the influence of humidity is very low. This miniaturized fiber optical sensor in combination with an easy-to-handle and non-sophisticated measuring and evaluation unit is excellently suitable for the remote sensing of special organic solvent vapors.

  17. Molecular Plasmonics.

    PubMed

    Wilson, Andrew J; Willets, Katherine A

    2016-06-12

    In this review, we survey recent advances in the field of molecular plasmonics beyond the traditional sensing modality. Molecular plasmonics is explored in the context of the complex interaction between plasmon resonances and molecules and the ability of molecules to support plasmons self-consistently. First, spectroscopic changes induced by the interaction between molecular and plasmonic resonances are discussed, followed by examples of how tuning molecular properties leads to active molecular plasmonic systems. Next, the role of the position and polarizability of a molecular adsorbate on surface-enhanced Raman scattering signals is examined experimentally and theoretically. Finally, we introduce recent research focused on using molecules as plasmonic materials. Each of these examples is intended to highlight the role of molecules as integral components in coupled molecule-plasmon systems, as well as to show the diversity of applications in molecular plasmonics.

  18. Performance Improvement of Polymer Solar Cells by Surface-Energy-Induced Dual Plasmon Resonance.

    PubMed

    Yao, Mengnan; Shen, Ping; Liu, Yan; Chen, Boyuan; Guo, Wenbin; Ruan, Shengping; Shen, Liang

    2016-03-09

    The surface plasmon resonance (SPR) effect of metal nanoparticles (MNPs) is effectively applied on polymer solar cells (PSCs) to improve power conversion efficiency (PCE). However, universality of the reported results mainly focused on utilizing single type of MNPs to enhance light absorption only in specific narrow wavelength range. Herein, a surface-energy-induced dual MNP plasmon resonance by thermally evaporating method was presented to achieve the absorption enhancement in wider range. The differences of surface energy between silver (Ag), gold (Au), and tungsten trioxide (WO3) compared by contact angle images enable Ag and Au prefer to respectively aggregate into isolated islands rather than films at the initial stage of the evaporation process, which was clearly demonstrated in the atomic force microscopy (AFM) measurement. The sum of plasmon-enhanced wavelength range induced by both Ag NPs (350-450 nm) and Au NPs (450-600 nm) almost cover the whole absorption spectra of active layers, which compatibly contribute a significant efficiency improvement from 4.57 ± 0.16 to 6.55 ± 0.12% compared to the one without MNPs. Besides, steady state photoluminescence (PL) measurements provide strong evidence that the SPR induced by the Ag-Au NPs increase the intensity of light absorption. Finally, ultraviolet photoelectron spectroscopy (UPS) reveals that doping Au and Ag causes upper shift of both the work function and valence band of WO3, which is directly related to hole collection ability. We believe the surface-energy-induced dual plasmon resonance enhancement by simple thermally evaporating technique might pave the way toward higher-efficiency PSCs.

  19. Sensitivity of metal nanoparticle surface plasmon resonance to the dielectric environment.

    PubMed

    Miller, Molly M; Lazarides, Anne A

    2005-11-24

    Electrodynamic simulations of gold nanoparticle spectra were used to investigate the sensitivity of localized surface plasmon band position to the refractive index, n, of the medium for nanoparticles of various shapes and nanoshells of various structures. Among single-component nanoparticles less than 130 nm in size, sensitivities of dipole resonance positions to bulk refractive index are found to depend only upon the wavelength of the resonance and the dielectric properties of the metal and the medium. Among particle plasmons that peak in the frequency range where the real part of the metal dielectric function varies linearly with wavelength and the imaginary part is small and slowly varying, the sensitivity of the peak wavelength, lambda, to refractive index, n, is found to be a linearly increasing function of lambda, regardless of the structural features of the particle that determine lambda. Quasistatic theory is used to derive an analytical expression for the refractive index sensitivity of small particle plasmon peaks. Through this analysis, the dependence of sensitivity on band position is found to be determined by the wavelength dependence of the real part, epsilon', of the particle dielectric function, and the sensitivity results are found to extend to all particles with resonance conditions of the form, epsilon' = -2chin(2), where chi is a function of geometric parameters and other constants. The sensitivity results observed using accurate computational methods for dipolar plasmon bands of gold nanodisks, nanorods, and hollow nanoshells extend, therefore, to particles of other shapes (such as hexagonal and chopped tetrahedral), composed of other metals, and to higher-order modes. The bulk refractive index sensitivity yielded by the theory serves as an upper bound to sensitivities of nanoparticles on dielectric substrates and sensitivities of nanoparticles to local refractive index changes, such as those associated with biomolecule sensing.

  20. Spectral response of localized surface plasmon in resonance with mid-infrared light

    SciTech Connect

    Kusa, Fumiya; Ashihara, Satoshi

    2014-10-21

    We study spectral responses of localized surface plasmons (LSPs) in gold nanorods, which resonate at mid-infrared frequencies, by transmission spectroscopy and electromagnetic field analyses. The resonance linewidth is found to be linearly proportional to the resonance frequency, indicating that the dephasing due to Drude relaxation is suppressed and that the overall dephasing is dominated by radiative damping. Owing to the reduced radiative/non-radiative damping and large geometrical length of the nanorod, near-field intensity enhancement exceeds several hundred times. Nonetheless the resonance linewidth is comparable with or larger than the bandwidth of a 100-fs pulse, and therefore the enhanced near-field as short as 100-fs can be created upon pulsed excitation. The large enhancements with appropriate bandwidths make LSPs promising for enhanced nonlinear spectroscopies, coherent controls, and strong-field light-matter interactions in the mid-infrared range.

  1. Engineering the magnetic plasmon resonances of metamaterials for high-quality sensing.

    PubMed

    Chen, Jing; Fan, Wenfang; Zhang, Tao; Tang, Chaojun; Chen, Xingyu; Wu, Jingjing; Li, Danyang; Yu, Ying

    2017-02-20

    We present a powerful method to enhance the magnetic plasmon (MP) resonances of metamaterials composed of periodic arrays of U-shaped metallic split-ring resonators (SRRs) for high-quality sensing. We show that by suspending the metamaterials to reduce the effect of the substrate, the strong diffraction coupling of MP resonances can be achieved, which leads to a narrow-band mixed MP mode with a large magnetic field enhancement. It is also shown that for such a diffraction coupling, the magnetic field component of the lattice resonance mode of periodic arrays must be parallel to the induced magnetic moment in the metallic SRRs. Importantly, the sensitivity and the figure of merit (FOM) of the suspended metamaterials can reach as high as 1300 nm/RIU and 40, respectively. These results suggest that the proposed metamaterials may find great potential applications in label-free biomedical sensing.

  2. Efficient Heterostructures for Combined Interference and Plasmon Resonance Raman Amplification.

    PubMed

    Alvarez-Fraga, Leo; Climent-Pascual, Esteban; Aguilar-Pujol, Montserrat; Ramírez-Jiménez, Rafael; Jiménez-Villacorta, Félix; Prieto, Carlos; de Andrés, Alicia

    2017-02-01

    The detection, identification, and quantification of different types of molecules and the optical imaging of, for example, cellular processes are important challenges. Here, we present how interference-enhanced Raman scattering (IERS) in adequately designed heterostructures can provide amplification factors relevant for both detection and imaging. Calculations demonstrate that the key factor is maximizing the absolute value of the refractive indices' difference between dielectric and metal layers. Accordingly, Si/Al/Al2O3/graphene heterostructures have been fabricated by optimizing the thickness and roughness and reaching enhancement values up to 700 for 488 nm excitation. The deviation from the calculated enhancement, 1200, is mainly due to reflectivity losses and roughness of the Al layer. The IERS platforms are also demonstrated to improve significantly the quality of white light images of graphene and are foreseen to be adequate to reveal the morphology of 2D and biological materials. A graphene top layer is adequate for most organic molecule deposition and often quenches possible fluorescence, permitting Raman signal detection, which, for a rhodamine 6G (R6G) monolayer, presents a gain of 400. Without graphene, the nonquenched R6G fluorescence is similarly amplified. The wavelength dependence of the involved refractive indices predicts much higher amplification (around 10(4)) for NIR excitation. These interference platforms can therefore be used to gain contrast and intensity in white light, Raman, and fluorescence imaging. We also demonstrate that surface-enhanced Raman scattering and IERS amplifications can be efficiently combined, leading to a gain of >10(5) (at 488 nm) by depositing a Ag nanostructured transparent film on the IERS platform. When the plasmonic structures deposited on the IERS platforms are optimized, single-molecule detection can be actively envisaged.

  3. Synthesis of gold nanorods with a longitudinal surface plasmon resonance peak of around 1250 nm

    NASA Astrophysics Data System (ADS)

    Nguyen, Thi Nhat Hang; Le Trinh Nguyen, Thi; Thanh Tuyen Luong, Thi; Thang Nguyen, Canh Minh; Nguyen, Thi Phuong Phong

    2016-03-01

    We prepared gold nanorods and joined them to chemicals such as tetrachloauric (III) acid trihydrate, silver nitrate, hydroquinone, hexadecyltrimethylammonium bromide, sodium hydroxide and sodium borohydride using the seed-mediated method. The combination of hydroquinone, with or without salicylic acid, influences the size of the gold nanorods, and this is demonstrated by the results of TEM images, UV-vis spectra and the value of the longitudinal surface plasmon resonance peak with respect to the UV-vis spectra. By changing the Ag+ ion and hydroquinone concentration and the combination of hydroquinone and salicylic acid, the size of the gold nanorods can be controlled and this is manifested by longitudinal surface plasmon resonance peaks forming between 875 and 1278 nm. In particular, sample E2 achieved a longitudinal surface plasmon peak at 1273 nm and an aspect ratio of more than 10 by modifying the hydroquinone to 2.5 mM and salicylic acid to 0.5 mM concentration in the growth solution.

  4. Resonant tunneling assisted propagation and amplification of plasmons in high electron mobility transistors

    SciTech Connect

    Bhardwaj, Shubhendu; Sensale-Rodriguez, Berardi; Xing, Huili Grace; Rajan, Siddharth; Volakis, John L.

    2016-01-07

    A rigorous theoretical and computational model is developed for the plasma-wave propagation in high electron mobility transistor structures with electron injection from a resonant tunneling diode at the gate. We discuss the conditions in which low-loss and sustainable plasmon modes can be supported in such structures. The developed analytical model is used to derive the dispersion relation for these plasmon-modes. A non-linear full-wave-hydrodynamic numerical solver is also developed using a finite difference time domain algorithm. The developed analytical solutions are validated via the numerical solution. We also verify previous observations that were based on a simplified transmission line model. It is shown that at high levels of negative differential conductance, plasmon amplification is indeed possible. The proposed rigorous models can enable accurate design and optimization of practical resonant tunnel diode-based plasma-wave devices for terahertz sources, mixers, and detectors, by allowing a precise representation of their coupling when integrated with other electromagnetic structures.

  5. Numerical investigation into a surface plasmon resonance sensor based on optical fiber microring

    NASA Astrophysics Data System (ADS)

    Zhao, Chunliu; Wang, Yanru; Wang, Dongning; Ding, Zhewen

    2017-01-01

    A reflective surface plasmon resonance (SPR) sensor based on optical fiber microring is proposed. In such a sensor, plasmons on the outer surface of the metallized channels containing analyte can be excited by a fundamental mode of a thin-core fiber (TCF). The refractive index (RI) sensing can be achieved as the surface plasmons are sensitive to changes in the refrective index of the analyte. Numerical simulation results show that the resonance spectrum shifts toward the shorter wavelength gradually when the analyte refractive index increases from 1.0 to 1.33, whereas it shifts toward the longer wavelength gradually when the analyte refractive index increases from 1.33 to 1.43, and there is a turning point at the refractive index value of 1.33. The highest sensitivity achieved is up to 2.30×103 nm/RIU near the refractive index value of 1.0. Such a compact sensor has potential in gaseous substance monitoring.

  6. Resonant tunneling assisted propagation and amplification of plasmons in high electron mobility transistors

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Shubhendu; Sensale-Rodriguez, Berardi; Xing, Huili Grace; Rajan, Siddharth; Volakis, John L.

    2016-01-01

    A rigorous theoretical and computational model is developed for the plasma-wave propagation in high electron mobility transistor structures with electron injection from a resonant tunneling diode at the gate. We discuss the conditions in which low-loss and sustainable plasmon modes can be supported in such structures. The developed analytical model is used to derive the dispersion relation for these plasmon-modes. A non-linear full-wave-hydrodynamic numerical solver is also developed using a finite difference time domain algorithm. The developed analytical solutions are validated via the numerical solution. We also verify previous observations that were based on a simplified transmission line model. It is shown that at high levels of negative differential conductance, plasmon amplification is indeed possible. The proposed rigorous models can enable accurate design and optimization of practical resonant tunnel diode-based plasma-wave devices for terahertz sources, mixers, and detectors, by allowing a precise representation of their coupling when integrated with other electromagnetic structures.

  7. Plane wave excitation-detection of non-resonant plasmons along finite-width graphene strips.

    PubMed

    Gómez-Díaz, J S; Esquius-Morote, M; Perruisseau-Carrier, J

    2013-10-21

    An approach to couple free-space waves and non-resonant plasmons propagating along graphene strips is proposed based on the periodic modulation of the graphene strip width. The solution is technologically very simple, scalable in frequency, and provides customized coupling angle and intensity. Moreover, the coupling properties can be dynamically controlled at a fixed frequency via the graphene electrical field effect, enabling advanced and flexible plasmon excitation-detection strategies. We combine a previously derived scaling law for graphene strips with leaky-wave theory borrowed from microwaves to achieve rigorous and efficient modeling and design of the structure. In particular we analytically derive its dispersion, predict its coupling efficiency and radiated field structure, and design strip configurations able to fulfill specific coupling requirements. The proposed approach and developed methods are essential to the recent and fundamental problem of the excitation-detection of non-resonant plasmons propagating along a continuous graphene strip, and could pave the way to smart all-graphene sensors and transceivers.

  8. Plasmon-coupled resonance energy transfer: A real-time electrodynamics approach

    NASA Astrophysics Data System (ADS)

    Ding, Wendu; Hsu, Liang-Yan; Schatz, George C.

    2017-02-01

    This paper presents a new real-time electrodynamics approach for determining the rate of resonance energy transfer (RET) between two molecules in the presence of plasmonic or other nanostructures (inhomogeneous absorbing and dispersive media). In this approach to plasmon-coupled resonance energy transfer (PC-RET), we develop a classical electrodynamics expression for the energy transfer matrix element which is evaluated using the finite-difference time-domain (FDTD) method to solve Maxwell's equations for the electric field generated by the molecular donor and evaluated at the position of the molecular acceptor. We demonstrate that this approach yields RET rates in homogeneous media that are in precise agreement with analytical theory based on quantum electrodynamics (QED). In the presence of gold nanoparticles, our theory shows that the long-range decay of the RET rates can be significantly modified by plasmon excitation, with rates increased by as much as a factor of 106 leading to energy transfer rates over hundreds of nm that are comparable to that over tens of nm in the absence of the nanoparticles. These promising results suggest important future applications of the PC-RET in areas involving light harvesting or sensing, where energy transfer processes involving inhomogeneous absorbing and dispersive media are commonplace.

  9. Ultrathin suspended nanopores with surface plasmon resonance fabricated by combined colloidal lithography and film transfer.

    PubMed

    Junesch, Juliane; Sannomiya, Takumi

    2014-05-14

    Suspended plasmonic nanopores in ultrathin film layers were fabricated through a simple and widely applicable method combining colloidal lithography and thin film transfer, which allows mass production of short-range ordered nanopore arrays on a large scale. By this combined method, mechanically stable and flexible free-standing nanopore membranes with a thickness down to 15-30 nm were produced. The plasmon resonances of the ultrathin plasmonic nanopores fabricated in AlN/Au/AlN trilayer and single layer Au membranes were tuned to lie in the vis-NIR wavelength range by properly designing their dimensions. The optical responses to the refractive index changes were tested and applied to adlayer sensing. The trilayer nanopore membrane showed a unique property to support water only on one side of the membrane, which was confirmed by the resonance shift and comparison with numerical simulation. Pore size reduction down to 10 nm can be achieved through additional material deposition. The filtering function of such pore-size-reduced conical shaped nanofunnels has also been demonstrated. The presented nanopore fabrication method offers new platforms for ultrathin nanopore sensing or filtering devices with controlled pore-size and optical properties. The film transfer technique employed in this work would enable the transformation of any substrate-based nanostructures to free-standing membrane based devices without complicated multiple etching processes.

  10. Plasmon-coupled resonance energy transfer: A real-time electrodynamics approach.

    PubMed

    Ding, Wendu; Hsu, Liang-Yan; Schatz, George C

    2017-02-14

    This paper presents a new real-time electrodynamics approach for determining the rate of resonance energy transfer (RET) between two molecules in the presence of plasmonic or other nanostructures (inhomogeneous absorbing and dispersive media). In this approach to plasmon-coupled resonance energy transfer (PC-RET), we develop a classical electrodynamics expression for the energy transfer matrix element which is evaluated using the finite-difference time-domain (FDTD) method to solve Maxwell's equations for the electric field generated by the molecular donor and evaluated at the position of the molecular acceptor. We demonstrate that this approach yields RET rates in homogeneous media that are in precise agreement with analytical theory based on quantum electrodynamics (QED). In the presence of gold nanoparticles, our theory shows that the long-range decay of the RET rates can be significantly modified by plasmon excitation, with rates increased by as much as a factor of 10(6) leading to energy transfer rates over hundreds of nm that are comparable to that over tens of nm in the absence of the nanoparticles. These promising results suggest important future applications of the PC-RET in areas involving light harvesting or sensing, where energy transfer processes involving inhomogeneous absorbing and dispersive media are commonplace.

  11. Visualization of biosensors using enhanced surface plasmon resonances in capped silver nanostructures.

    PubMed

    Lee, Kuang-Li; You, Meng-Lin; Tsai, Cheng-Lin; Hung, Chia-Yu; Hsieh, Shu-Yi; Wei, Pei-Kuen

    2016-02-07

    We propose a method and optical design for direct visualization of label-free detection. The system, similar to a tiny spectral analyzer, is composed of a nanostructure-based surface plasmon resonance chip, linear polarizer and 532 nm laser light source. The full-width-at-half-maximum bandwidths of the enhanced surface plasmon resonances are about 5 nm. The distribution of the transmitted light from these arrays comprises a spectral image on the chip. The qualitative and quantitative analyses of the analyte can be conducted by observing the spot shift on the chip. We tested the sensing capability of the chip. The detectable surface mass density with the naked eye is about 0.476 μg cm(-2). In addition, antigen-antibody interaction experiments are conducted to verify the surface binding measurements. A monolayer protein attached on the chip can be directly observed and the concentration levels of the analyte can be estimated with the naked eye. Such plasmonic biochips can benefit sensing applications in point-of-care diagnostics.

  12. Separation by nanoparticles plasmonic resonance with low stress in microfluidics channel (analytical and design).

    PubMed

    SalmanOgli, Ahmad; Farhadnia, Farshad; Piskin, Erhan

    2016-08-01

    In this study, nanoparticles near-field plasmonic resonance is used to improve the traditional cell separation main outputs such as viability and efficiency. The live cells viability is severely depend on stresses, which are applied on cells in the microfluidics channel. Hence, for improving the cell viability, the enforced stresses inside of the structure should be declined. The major factors of the enforced stresses are related to the electric field non-uniformity, which are attributed to the hurdles and applied voltage magnitude. Therefore, in this study, a new structure is presented and thereby, the magnitude of the applied stresses on live cells is minimised which is contributed to the decreasing the non-uniformity strength of channel. It should be noted that in the new structure two arrays of nanoparticles were used to produce a short range and localised non-uniform electrical field because of their near-field plasmonic resonance. Hence, the enforced stress on the live cell severely decreased at the far-field and confined at the small section of the channel. It is due to, the near-field plasmonic amplitude is dramatically disappeared by increasing distance, hence, the cells far from the nanoparticles will be endured the low level but effective amount of the optical force.

  13. Passive Infrared Sensing Using Plasmonic Resonant Dust Particles

    DTIC Science & Technology

    2012-01-01

    1 R efl ec ta n ce 8 9 10 11 12 13 14 Incidence wavelength (μm) Polarization parallel to gold strips Polarization perpendicular to gold strips...since the orientation of 4 International Journal of Optics 0 0.5 1 1.5 R efl ec ta n ce 8 9 10 11 12 13 14 Incidence wavelength (μm) Normally incident...strong. The bandwidth of the resonance also remains relatively fixed as the substrate thicknesses is varied. 0 0.5 1 1.5 R efl ec ta n ce 8 9 10 11 12 13

  14. Investigation of surface plasmon resonance in composite nanostructure of silver film and nanowire array

    NASA Astrophysics Data System (ADS)

    Li, Jun; Yang, Junyi; Wu, Xingzhi; Song, Yinglin

    2016-10-01

    We investigate the surface plasmon resonance in a new composite nanostructure (Nanowires array beneath metal film). Computational simulation results exhibit that, for both transverse electric(TE) and transverse magnetic (TM) polarization, the positions of resonance peaks is extremely sensitive to the change of center distance (Filling ratio of nanowires). When the diameter of Nanowires is 4nm and under TM polarization, the resonance angle increasing with the increase of center distance. In the case of TE polarization, the result is completely the opposite within limits. It is also shown that changes in thickness of Ag film(At the top of the Ag nanowire) has little direct effect on the resonance angle, But the characteritics of SPR intensity is influenced by the thickness of Ag film in the most degree. When the thickness of Ag film is 50 nm, In range of 10nm to 100nm, the minimum value of the reflectance is only 0.05, the result is consistent with the previous studies. Additionally, the nano composite structure material is very sensitive to the refractive index change of the lowest layer when under the TE- polarization. we have done mode analysis of the SPR structure for both simple and practical structures using comsol multiphysics, our approach is intend to show the feasibity and extend the applicability of the plasmonic nanowires, could lead to provide the basis for design the new structure of nanowires array.

  15. Plasmonically Enhanced Photocatalytic Hydrogen Production from Water: The Critical Role of Tunable Surface Plasmon Resonance from Gold-Silver Nanoshells.

    PubMed

    Li, Chien-Hung; Li, Min-Chih; Liu, Si-Ping; Jamison, Andrew C; Lee, Dahye; Lee, T Randall; Lee, Tai-Chou

    2016-04-13

    Gold-silver nanoshells (GS-NSs) having a tunable surface plasmon resonance (SPR) were employed to facilitate charge separation of photoexcited carriers in the photocalytic production of hydrogen from water. Zinc indium sulfide (ZnIn2S4; ZIS), a visible-light-active photocatalyst, where the band gap varies with the [Zn]/[In] ratio, was used as a model ZIS system (E(g) = 2.25 eV) to investigate the mechanisms of plasmonic enhancement associated with the nanoshells. Three types of GS-NS cores with intense absorptions centered roughly at 500, 700, and 900 nm were used as seeds for preparing GS-NS@ZIS core-shell structures via a microwave-assisted hydrothermal reaction, yielding core-shell particles with composite diameters of ∼200 nm. Notably, an interlayer of dielectric silica (SiO2) between the GS-NSs and the ZIS photocatalyst provided another parameter to enhance the production of hydrogen and to distinguish the charge-transfer mechanisms. In particular, the direct transfer of hot electrons from the GS-NSs to the ZIS photocatalyst was blocked by this layer. Of the 10 particle samples examined in this study, the greatest hydrogen gas evolution rate was observed for GS-NSs having a SiO2 interlayer thickness of ∼17 nm and an SPR absorption centered at ∼700 nm, yielding a rate 2.6 times higher than that of the ZIS without GS-NSs. The apparent quantum efficiencies for these core-shell particles were recorded and compared to the absorption spectra. Analyses of the charge-transfer mechanisms were evaluated and are discussed based on the experimental findings.

  16. Determination of ribonuclease H surface enzyme kinetics by surface plasmon resonance imaging and surface plasmon fluorescence spectroscopy.

    PubMed

    Fang, Shiping; Lee, Hye Jin; Wark, Alastair W; Kim, Hyun Min; Corn, Robert M

    2005-10-15

    The kinetics of the ribonuclease H (RNase H) surface hydrolysis of RNA-DNA heteroduplexes formed on DNA microarrays was studied using a combination of real-time surface plasmon resonance imaging (SPRI) and surface plasmon fluorescence spectroscopy (SPFS). Time-dependent SPRI and SPFS data at various enzyme concentrations were quantitatively analyzed using a simple model that couples diffusion, enzyme adsorption, and surface enzyme kinetics. This model is characterized by a set of three rate constants, enzyme adsorption (k(a)), enzyme desorption (k(d)), enzyme catalysis (k(cat)), and one dimensionless diffusion parameter (beta). Values of k(a) = 3.15 (+/-0.20) x 10(6) M(-1).s(-1), k(d) = 0.10 (+/-0.05) s(-1), and k(cat) = 0.95 (+/-0.10) s(-1) were determined from fitting all of the SPRI and SPFS data sets. One of the most interesting kinetic parameters is the surface RNase H hydrolysis reaction rate constant (k(cat)), which was found to be approximately 10 times slower than that observed in solution, but approximately 100 times faster than that recently observed for the exonuclease III surface hydrolysis of double-stranded DNA microarrays (k(cat) = 0.009 s(-1)). Moreover, the surface coverage of the intermediate enzyme-substrate complex (ES) was found to be extremely small during the course of the reaction because k(cat) is much larger than the product of k(a) and the bulk enzyme concentration.

  17. Nano-polarization-converter based on magnetic plasmon resonance excitation in an L-shaped slot antenna.

    PubMed

    Yang, Jing; Zhang, Jiasen

    2013-04-08

    We propose a nano-polarization-converter made of a resonant L-shaped slot antenna in a gold film and study its optical properties using the finite-difference time-domain method. Phase retardation between the fast and slow axes of the nano-polarization-converter originates from the simultaneous excitation of both single-surface first-order magnetic plasmon resonance mode and second-order magnetic plasmon resonance mode at the working wavelength. By adjusting the size of the slot antenna, which is still much smaller than the wavelength, the working wavelength can be tuned within a large wavelength range.

  18. Multiple plasmon resonance in a concentric silver-atomic medium nanoshell

    NASA Astrophysics Data System (ADS)

    Liu, Wenxiao; Wang, Xin; Chai, Yaqin; Gao, Shaoyan; Li, Fuli

    2017-03-01

    Optical properties of a concentric silver-atomic medium nanoshell are investigated based on the quasi-static and Maxwell-Garnett approximations. We consider the atomic medium as Λ-type three-level atoms driven simultaneously by a coupling field and a probe field. It is shown that the strong coupling between atoms and sphere plasmon of silver core emerges of multiple-mode and ultra narrow-band absorption spectra by controlling the permittivity of the atomic medium. In particular, coherent driving of the coupling field allows us to manipulate surface plasmon resonances, including frequency shift and bandwidth modification. Furthermore, we demonstrate that selective absorption enhancement of different modes can be achieved by tuning the radius of the core and the shell. These absorption properties yield potential applications of the nanoshells as ultracompact tunable nonlinear optical devices.

  19. Label-free imaging, detection, and mass measurement of single viruses by surface plasmon resonance

    PubMed Central

    Wang, Shaopeng; Shan, Xiaonan; Patel, Urmez; Huang, Xinping; Lu, Jin; Li, Jinghong; Tao, Nongjian

    2010-01-01

    We report on label-free imaging, detection, and mass/size measurement of single viral particles in solution by high-resolution surface plasmon resonance microscopy. Diffraction of propagating plasmon waves along a metal surface by the viral particles creates images of the individual particles, which allow us to detect the binding of the viral particles to surfaces functionalized with and without antibodies. We show that the intensity of the particle image is related to the mass of the particle, from which we determine the mass and mass distribution of influenza viral particles with a mass detection limit of approximately 1 ag (or 0.2 fg/mm2). This work demonstrates a multiplexed method to measure the masses of individual viral particles and to study the binding activity of the viral particles. PMID:20798340

  20. Electro-optically modulated localized surface plasmon resonance biosensors with gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Wang, Tzyy-Jiann; Lin, Wen-Shao

    2006-10-01

    An integrated-optic biosensor based on electro-optically modulated localized surface plasmon resonance (LSPR) is demonstrated. This biosensor utilizes the electro-optic effect to modulate the wave vector of incident lightwave used to excite localized surface plasmons. Electro-optically modulated LSPR results in the analyte-dependent variation of output intensity with the applied voltage. The linear regression slope of this relation is used to determine the analyte concentration. On the sensing region of LSPR biosensor, human serum albumin is self-assembled on gold nanoparticles in order to sense the beta-blocker concentration. The use of the presented biosensor has the features of no intensity drift problem, no absorption diversity problem in different sample media, and noise reduction by linear regression analysis.

  1. Resonant plasmon-axion excitations induced by charge density wave order in a Weyl semimetal

    NASA Astrophysics Data System (ADS)

    Redell, Matthew D.; Mukherjee, Shantanu; Lee, Wei-Cheng

    2016-06-01

    We investigate the charge excitations of a Weyl semimetal in the axionic charge density wave (axionic CDW) state. While it has been shown that the topological response (anomalous Hall conductivity) is protected against the CDW state, we find that the long-wavelength plasmon excitation is radically influenced by the dynamics of the CDW order parameter. In the normal state, we show that an undamped collective mode should exist at q ⃗≈Q⃗CDW if there is an attractive interaction favoring the formation of the CDW state. The undamped nature of this collective mode is attributed to a gaplike feature in the particle-hole continuum at q ⃗≈Q⃗CDW due to the chirality of the Weyl nodes, which is not seen in other materials with CDW instability. In the CDW state, the long-wavelength plasmon excitations become more dispersive due to the additional interband scattering not allowed in the normal state. Moreover, because the translational symmetry is spontaneously broken, umklapp scattering, the process conserving the total momentum only up to n Q⃗CDW , with n an integer and Q⃗CDW the ordering wave vector, emerges in the CDW state. We find that the plasmon excitation couples to the phonon mode of the CDW order via the umklapp scattering, leading to two branches of resonant collective modes observable in the density-density correlation function at q ⃗≈0 and q ⃗≈Q⃗CDW . Based on our analysis, we propose that measuring these resonant plasmon-axion excitations around q ⃗≈0 and q ⃗≈Q⃗CDW by momentum-resolved electron energy loss spectroscopy could serve as a reliable way to detect the axionic CDW state in Weyl semimetals.

  2. Guiding light by plasmonic resonant solitons in metallic nanosuspensions (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Kelly, Trevor S.; Samadi, Akbar; Bezryadina, Anna; Chen, Zhigang

    2015-09-01

    In typical colloidal suspensions, the corresponding optical polarizability is positive, and thus enhanced scattering takes place as optical beams tend to catastrophically collapse during propagation. Recently, light penetration deep inside scattering suspensions has been realized by engineering dielectric or plasmonic nanoparticle polarizibilities. In particular, we have previously demonstrated two types of soft-matter systems with tunable optical nonlinearities - the dielectric and metallic colloidal suspensions, in which the effects of diffraction and scattering were overcome, hence achieving deep penetration of a light needle through the suspension. In this work, we show that waveguides can be established in soft matter systems such as metallic nanosuspensions through the formation of plasmonic resonant solitons. First, we show that, due to plasmonic resonance, a 1064nm laser beam (probe) would not experience appreciable nonlinear self-action while propagating through 4cm cuvette containing the metallic nanosuspension of gold spheres (40nm), whereas a 532nm laser beam (pump) can readily form a spatial soliton due to nonlinear self-trapping. Second, we demonstrate effective guidance of the probe beam, which would otherwise diffract significantly through the nanosuspensions, due to the soliton-induced waveguide from the pump beam. Such guidance was observed when the power of the probe beam was varied from 20mW to 500mW at constant pump beam power, with more pronounced guidance realized from lower to higher probe beam power. Interestingly, due to the presence of the probe beam, the pump beam undergoes self-trapping at an even lower power. These results may bring about the possibility of engineering plasmonic soliton-based waveguides for many applications.

  3. Localized surface plasmon resonance sensors based on wavelength-tunable spectral dips

    NASA Astrophysics Data System (ADS)

    Kazuma, Emiko; Tatsuma, Tetsu

    2014-01-01

    Localized surface plasmon resonance (LSPR) sensors serve as sensitive analytical tools based on refractive index changes, which can be applied to affinity-based chemical sensing and biosensing. However, to select the monitoring wavelength, monodisperse Au or Ag nanoparticles must be synthesized. Here we developed LSPR sensors that operate at arbitrary wavelengths after preirradiation at the corresponding wavelength. Polydisperse plasmonic Ag nanospheroids or nanorods are photocatalytically deposited on TiO2. The nanoparticle ensemble shows a broad absorption band over the visible and near infrared regions, and absorption dips can be formed at desired wavelengths simply by photoexciting the ensemble at the wavelengths, on the basis of plasmon-induced charge separation. The dips redshift linearly in response to a positive change of refractive index, and the refractive index sensitivity linearly increases with increasing dip wavelength (e.g., 356 nm RIU-1 at 1832 nm). The dip-based sensor is applied to monitoring of selective binding between biotin and streptavidin. The present system would allow development of miniaturized and cost-effective sensors that operate at the optimum wavelength at which the sensitivity is highest within the optical window of the sample.Localized surface plasmon resonance (LSPR) sensors serve as sensitive analytical tools based on refractive index changes, which can be applied to affinity-based chemical sensing and biosensing. However, to select the monitoring wavelength, monodisperse Au or Ag nanoparticles must be synthesized. Here we developed LSPR sensors that operate at arbitrary wavelengths after preirradiation at the corresponding wavelength. Polydisperse plasmonic Ag nanospheroids or nanorods are photocatalytically deposited on TiO2. The nanoparticle ensemble shows a broad absorption band over the visible and near infrared regions, and absorption dips can be formed at desired wavelengths simply by photoexciting the ensemble at the

  4. Surface plasmon resonance system with magneto-optic garnet

    NASA Astrophysics Data System (ADS)

    Vlček, Jaroslav; Pištora, Jaromír.; Halagačka, Lukáš

    2016-12-01

    We demonstrate the model specification of the MO-SPR coupling-prism system consisting of the Ag film deposited between two garnet layers; the water is supposed as an analyte. The bismuth-doped gallium-gadolinium iron garnet offers low optical losses as well as strong MO response from visible to near infrared optical region. We apply two different response functions that detect a change of analyte refractive index that operate either directly with reflectance change at appropriate incidence angle or with the magneto-optically highlighted SP resonance dip shift. Suggested sensitivity criteria lead to the sensitivity about 120 1/RIU or 75 deg/RIU with the resolution of the order 10-5 RIU by experimentally acceptable variation of response factors.

  5. Inductive tuning of Fano-resonant metasurfaces using plasmonic response of graphene in the mid-infrared.

    PubMed

    Mousavi, S Hossein; Kholmanov, Iskandar; Alici, Kamil B; Purtseladze, David; Arju, Nihal; Tatar, Kaya; Fozdar, David Y; Suk, Ji Won; Hao, Yufeng; Khanikaev, Alexander B; Ruoff, Rodney S; Shvets, Gennady

    2013-03-13

    Graphene is widely known for its anomalously strong broadband optical absorptivity of 2.3% that enables seeing its single-atom layer with the naked eye. However, in the mid-infrared part of the spectrum graphene represents a quintessential lossless zero-volume plasmonic material. We experimentally demonstrate that, when integrated with Fano-resonant plasmonic metasurfaces, single-layer graphene (SLG) can be used to tune their mid-infrared optical response. SLG's plasmonic response is shown to induce large blue shifts of the metasurface's resonance without reducing its spectral sharpness. This effect is explained by a generalized perturbation theory of SLG-metamaterial interaction that accounts for two unique properties of the SLG that set it apart from all other plasmonic materials: its anisotropic response and zero volume. These results pave the way to using gated SLG as a platform for dynamical spectral tuning of infrared metamaterials and metasurfaces.

  6. Polarization-induced tunability of localized surface plasmon resonances in arrays of sub-wavelength cruciform apertures.

    PubMed

    Thompson, Paul G; Biris, Claudiu G; Osley, Edward J; Gaathon, Ophir; Osgood, Richard M; Panoiu, Nicolae C; Warburton, Paul A

    2011-12-05

    We demonstrate experimentally that by engineering the structural asymmetry of the primary unit cell of a symmetrically nanopatterned metallic film the optical transmission becomes strongly dependent on the polarization of the incident wave. By considering a specific plasmonic structure consisting of square arrays of nanoscale asymmetric cruciform apertures we show that the enhanced optical anisotropy is induced by the excitation inside the apertures of localized surface plasmon resonances. The measured transmission spectra of these plasmonic arrays show a transmission maximum whose spectral location can be tuned by almost 50% by simply varying the in-plane polarization of the incident photons. Comprehensive numerical simulations further prove that the maximum of the transmission spectra corresponds to polarization-dependent surface plasmon resonances tightly confined in the two arms of the cruciform aperture. Despite this, there are isosbestic points where the transmission, reflection, and absorption spectra are polarization-independent, regardless of the degree of asymmetry of the apertures.

  7. Optical Switching of Nematic Liquid Crystal Film based on Localized Surface Plasmon Resonance

    NASA Astrophysics Data System (ADS)

    Quint, Makiko; Delgado, Silverio; Nuno, Zachary; Hirst, Linda; Ghosh, Sayantani

    2015-03-01

    We have demonstrated an all-optical technique to reversibly switch the spatial orientation of nematic liquid crystal molecules from homeotropic to planar in a few micron thick films. Our method leverages the highly localized electric fields that are generated in the near-field of a densely packed gold nanoparticle layer when the samples are excited by light resonant with the localized surface plasmon absorption. We present simulations and control measurements for off-resonance excitation, where the switching behavior is not observed. Using polarized microscopy and transmission measurements, we observe this switching over a temperature range starting several degrees below and up to the isotropic transition, and at on-resonance excitation power less than 10 μW. In addition, we controllably vary the in-plane directionality of the liquid crystal molecules in the planar state by altering the linear polarization of the incident excitation. This work is supported by NSF Grant No. DMR-1056860 and ECC-1227034.

  8. Graphene coated fiber optic surface plasmon resonance biosensor for the DNA hybridization detection: Simulation analysis

    NASA Astrophysics Data System (ADS)

    Shushama, Kamrun Nahar; Rana, Md. Masud; Inum, Reefat; Hossain, Md. Biplob

    2017-01-01

    In this paper, a graphene coated optical fiber surface plasmon resonance (SPR) biosensor is presented for the detection of DNA Hybridization. For the proposed sensor, a four layer model (fiber core /metal /sensing layer /sample) where a sheet of graphene (biomolecular recognition elements (BRE)) acting as a sensing layer is coated around the gold film because graphene enhances the sensitivity of fiber optic SPR biosensor. Numerical analysis shows the variation of resonance wavelength and spectrum of transmitted power for mismatched DNA strands and for complementary DNA strands. For mismatched DNA strands variation is negligible whereas for complementary DNA strands is considerably countable. Proposed sensor successfully distinguishes hybridization and single nucleotide polymorphisms (SNP) by observing the variation level of resonance wavelength and spectrum of transmitted power.

  9. Dual coupled-resonator system for plasmon-induced transparency and slow light effect

    NASA Astrophysics Data System (ADS)

    Wang, Qinghao; Meng, Hongyun; Huang, Ben; Wang, Huihao; Zhang, Xing; Yu, Wei; Tan, Chunhua; Huang, Xuguang; Li, Shuti

    2016-12-01

    We proposed a dual coupled-resonator system based on the metal-insulator-metal bus waveguide and numerically investigated the plasmon-induced transparency and slow light effect with the Finite-Difference Time-Domain simulations in this paper. The electromagnetically induced transparency-like spectral response will occur between two adjacent stub resonators with detuned resonant wavelength due to the phase-coupled effect. The transmissivity and group index equations were been deduced, which indicated that the system can achieve the effect of the multiple electromagnetically induced transparency-like and slow light. With the optimization, the single peak transmission can reach to as high as 92%, dual PIT transmission peaks appear, as well as group index can reach over 75. These characteristics indicate multiple applications of our system in integrated optical circuits.

  10. Aluminum for nonlinear plasmonics: resonance-driven polarized luminescence of Al, Ag, and Au nanoantennas.

    PubMed

    Castro-Lopez, Marta; Brinks, Daan; Sapienza, Riccardo; van Hulst, Niek F

    2011-11-09

    Resonant optical antennas are ideal for nanoscale nonlinear optical interactions due to their inherent strong local field enhancement. Indeed second- and third-order nonlinear response of gold nanoparticles has been reported. Here we compare the on- and off-resonance properties of aluminum, silver, and gold nanoantennas, by measuring two-photon photoluminescence. Remarkably, aluminum shows 2 orders of magnitude higher luminescence efficiency than silver or gold. Moreover, in striking contrast to gold, the aluminum emission largely preserves the linear incident polarization. Finally, we show the systematic resonance control of two-photon excitation and luminescence polarization by tuning the antenna width and length independently. Our findings point to aluminum as a promising metal for nonlinear plasmonics.

  11. Determination of quality and adulteration of tequila through the use of surface plasmon resonance.

    PubMed

    Luna-Moreno, D; Monzón-Hernández, D; Noé-Arias, E; Regalado, L E

    2012-07-20

    In this work, the surface plasmon resonance (SPR) technique is used to determine the quality or adulteration of tequila beverages. Graphic analyses of the position and width of the SPR curve are related to the complex refractive index of the sample, showing differentiated regions where one can easily and unambiguously identify white, aged, or extra-aged tequilas, and even adulterated or low quality tequilas. The curves generated by aged and extra-aged tequilas, with respect to those obtained from white tequilas, are wider, while the resonant peak shifts towards larger angles. This behavior should be attributed to the aging process. The resonance curve is generated in 20 s, minimizing the variations of the SPR curve parameters due to temperature fluctuations.

  12. Self-assembly of large-scale and ultrathin silver nanoplate films with tunable plasmon resonance properties.

    PubMed

    Zhang, Xiao-Yang; Hu, Anming; Zhang, Tong; Lei, Wei; Xue, Xiao-Jun; Zhou, Yunhong; Duley, Walt W

    2011-11-22

    We describe a rapid, simple, room-temperature technique for the production of large-scale metallic thin films with tunable plasmonic properties assembled from size-selected silver nanoplates (SNPs). We outline the properties of a series of ultrathin monolayer metallic films (8-20 nm) self-assembled on glass substrates in which the localized surface plasmon resonance can be tuned over a range from 500 to 800 nm. It is found that the resonance peaks of the films are strongly dependent on the size of the nanoplates and the refractive index of the surrounding dielectric. It is also shown that the bandwidth and the resonance peak of the plasmon resonance spectrum of the metallic films can be engineered by simply controlling aggregation of the SNP. A three-dimensional finite element method was used to investigate the plasmon resonance properties for individual SNPs in different dielectrics and plasmon coupling in SNP aggregates. A 5-17 times enhancement of scattering from these SNP films has been observed experimentally. Our experimental results, together with numerical simulations, indicate that this self-assembly method shows great promise in the production of nanoscale metallic films with enormous electric-field enhancements at visible and near-infrared wavelengths. These may be utilized in biochemical sensing, solar photovoltaic, and optical processing applications.

  13. Characterizing ultrathin and thick organic layers by surface plasmon resonance three-wavelength and waveguide mode analysis.

    PubMed

    Granqvist, Niko; Liang, Huamin; Laurila, Terhi; Sadowski, Janusz; Yliperttula, Marjo; Viitala, Tapani

    2013-07-09

    A three-wavelength angular-scanning surface plasmon resonance based analysis has been utilized for characterizing optical properties of organic nanometer-thick layers with a wide range of thicknesses. The thickness and refractive index were determined for sample layers with thicknesses ranging from subnanometer to hundreds of nanometers. The analysis approach allows for simultaneous determination of both the refractive index and thickness without prior knowledge of either the refractive index or the thickness of the sample layers and without the help of other instruments, as opposed to current methods and approaches for characterizing optical properties of organic nanometer-thick layers. The applicability of the three-wavelength angular-scanning surface plasmon resonance approach for characterizing thin and thick organic layers was demonstrated by ex situ deposited mono- and multilayers of stearic acid and hydrogenated soy phosphatidylcholine and in situ layer-by-layer deposition of two different polyelectrolyte multilayer systems. In addition to the three-wavelength angular-scanning surface plasmon resonance approach, another surface plasmon resonance optical phenomenon, i.e., the surface plasmon resonance waveguide mode, was utilized to characterize organic sample layers whose thicknesses border the micrometer scale. This was demonstrated by characterizing both in situ layer-by-layer deposited polyelectrolyte multilayer systems and an ex situ deposited spin-coated polymer layer.

  14. Improved Biomolecular Thin-Film Sensor based on Plasmon Waveguide Resonance

    NASA Astrophysics Data System (ADS)

    Byard, Courtney; Aslan, Mustafa; Mendes, Sergio

    2009-05-01

    The design, fabrication, and characterization of a plasmon waveguide resonance (PWR) sensor are presented. Glass substrates are coated with a 35 nm gold film using electron beam evaporation, and then covered with a 143 nm aluminum oxide waveguide using an atomic layer deposition process, creating a smooth, highly transparent dielectric film. When probed in the Kretschmann configuration, the structure allows for an efficient conversion of an incident optical beam into a surface wave, which is mainly confined in the dielectric layer and exhibits a deep and narrow angular resonance. The performance (reflectance vs. incidence angle in TE polarization) is modeled using a transfer-matrix approach implemented into a Mathematica code. Our simulations and experimental data are compared with that of surface plasmon resonance (SPR) sensor using the same criteria. We show that the resolution of PWR is approximately ten times better than SPR, opening opportunities for more sensitive studies in various applications including research in protein interactions, pharmaceutical drug development, and food analysis.

  15. Plasmon resonance and the imaging of metal-impregnated neurons with the laser scanning confocal microscope

    PubMed Central

    Thompson, Karen J; Harley, Cynthia M; Barthel, Grant M; Sanders, Mark A; Mesce, Karen A

    2015-01-01

    The staining of neurons with silver began in the 1800s, but until now the great resolving power of the laser scanning confocal microscope has not been utilized to capture the in-focus and three-dimensional cytoarchitecture of metal-impregnated cells. Here, we demonstrate how spectral confocal microscopy, typically reserved for fluorescent imaging, can be used to visualize metal-labeled tissues. This imaging does not involve the reflectance of metal particles, but rather the excitation of silver (or gold) nanoparticles and their putative surface plasmon resonance. To induce such resonance, silver or gold particles were excited with visible-wavelength laser lines (561 or 640 nm), and the maximal emission signal was collected at a shorter wavelength (i.e., higher energy state). Because the surface plasmon resonances of noble metal nanoparticles offer a superior optical signal and do not photobleach, our novel protocol holds enormous promise of a rebirth and further development of silver- and gold-based cell labeling protocols. DOI: http://dx.doi.org/10.7554/eLife.09388.001 PMID:26670545

  16. Numerical analysis of surface plasmon resonance effects on a rotational silver nanorod/nanoshell dimer

    NASA Astrophysics Data System (ADS)

    Chou Chau, Yuan-Fong

    2013-06-01

    In this work, we numerically investigate the surface plasmon resonance (SPR) effects on a pair of rotational silver nanorod/nanoshell dimer with a finite height of 1000 nm by means of finite element method with three dimensional calculation. The rotational angles of the silver nanorod/nanoshell dimer are chosen θ=0°, θ=25°, θ=45° and θ=90°, respectively. The proposed structure exhibits a red-shifted localized SPR that can tuned over an extended wavelength range by varying the dielectric constant in metal nanoshell and the rotational angle of the silver nanorod/nanoshell dimer. The tunable optical properties on SPR phenomena are attributed to the rotational effect and a larger effective size of dielectric constant that is filled with a higher refractive medium of finite height of metal nanorod/nanoshell. This unique property of a pair of rotational nanorod/nanoshell dimer is highly attractive for serving as resonant center to hold and probe smaller nanostructures, such as biomolecules or quantum dots. Such structures also show significant promise for applications in nano-switch devices, sensing, and surface-enhanced spectroscopy, due to their strong and tunable plasmon resonances.

  17. Laser fields at flat interfaces: II. Plasmon resonances in aluminium photoelectron spectra

    NASA Astrophysics Data System (ADS)

    Raşeev, G.

    2012-07-01

    Using the model derived in paper I [G. Raşeev, Eur. Phys. J. D 66, 167 (2012)], this work presents calculations of the photoelectron spectrum (PES) of low index aluminium surfaces in the 10-30 eV region. The laser is p or transverse magnetic linearly polarized incident on a flat structureless surface and its fields are modeled in I using the vector potential in the temporal gauge. This model uses a tensor and non-local isotropic (TNLI) susceptibility and solves the classical Ampère-Maxwell equation through the use of the vector potential from the electron density-coupled integro-differential equations (VPED-CIDE). The PE cross sections are the squares of the PE transition moments calculated using the VPED-CIDE vector potential function of the penetration coordinate. The PES is obtained in a one step model using either the Fermi golden rule or the Weisskopf-Wigner (WW) expressions. The WW cross section PES compares favorably with the experimental angle and energy resolved photoelectron yield (AERPY) spectrum of Levinson et al. [Phys. Rev. Lett. 43, 952 (1979)], Levinson and Plummer [Phys. Rev. B 24, 628 (1981)] for Al(001) and of Barman et al. [Phys. Rev. B 58, R4285 (1998)], Barman [Curr. Sci. 88, 54 (2005)] for Al(111) surfaces. As in the experiment, our theoretical AERPY displays the multipole surface plasmon resonance at 11.32/12.75 eV for Al(001)/Al(111), mainly due to the surface contribution |⟨ψf|p·A|ψi⟩|2, the bulk plasmon minimum at 15 eV and the two single particle excitation resonances at about 16 and 22 eV. The nature of the plasmon resonances of the PES is analyzed using the reflectance, the electron density induced by the laser and Feibelman's parameter d⊥ all introduced in paper I.

  18. Quick and label-free detection for Coumaphos by using surface plasmon resonance biochip.

    PubMed

    Li, Ying; Ma, Xiao; Zhao, Minglu; Qi, Pan; Zhong, Jingang

    2014-01-01

    Coumaphos is a common organophosphorus pesticide used in agricultural products. It is harmful to human health and has a strictly stipulated maximum residue limit (MRL) on fruits and vegetables. Currently existing methods for detection are complex in execution, require expensive tools and are time consuming and labor intensive. The surface plasmon resonance method has been widely used in biomedicine and many other fields. This study discusses a detection method based on surface plasmon resonance in organophosphorus pesticide residues. As an alternative solution, this study proposes a method to detect Coumaphos. The method, which is based on surface plasmon resonance (SPR) and immune reaction, belongs to the suppression method. A group of samples of Coumaphos was detected by this method. The concentrations of Coumaphos in the samples were 0 µg/L, 50 µg/L, 100 µg/L, 300 µg/L, 500 µg/L, 1000 µg/L, 3000 µg/L and 5000 µg/L, respectively. Through detecting a group of samples, the process of kinetic reactions was analyzed and the corresponding standard curve was obtained. The sensibility is less than 25 µg/L, conforming to the standard of the MRL of Coumaphos stipulated by China. This method is label-free, using an unpurified single antibody only and can continuously test at least 80 groups of samples continuously. It has high sensitivity and specificity. The required equipments are simple, environmental friendly and easy to control. So this method is promised for a large number of samples quick detection on spot and for application prospects.

  19. Home-built Surface Plasmon Resonance Apparatus for Studying Interactions Between Water and a Hydrophobic Surface

    NASA Astrophysics Data System (ADS)

    McNany, Dylan; Brown, Erin; Petersen, Shannon; Poynor, Adele

    2014-03-01

    Water acts in many anomalous ways, especially when near a hydrophobic surface. Surface plasmon resonance (SPR), a quantum optical method is used to study these unusual effects. Through the use of SPR, studies of the depletion layer (a very thin low-density layer, only a few nanometers thick) can be conducted. Employing a home-built SPR device, along with a monolayer coated gold slide, studies are conducted using a variety of differing dielectrics (water, air, methanol). Modifications of the SPR apparatus allow us to find the assumed thickness of the depleted region.

  20. Fine golden rings: Tunable surface plasmon resonance from assembled nanorods in topological defects of liquid crystals

    SciTech Connect

    Lee, Elaine; Xia, Yu; Ferrier, Jr., Robert C.; Kim, Hye -Na; Gharbi, Mohamed A.; Stebe, Kathleen J.; Kamien, Randall D.; Composto, Russell J.; Yang, Shu

    2016-02-08

    Unprecedented, reversible, and dynamic control over an assembly of gold nanorods dispersed in liquid crystals (LC) is demonstrated. The LC director field is dynamically tuned at the nanoscale using microscale ring confinement through the interplay of elastic energy at different temperatures, thus fine-tuning its core replacement energy to reversibly sequester nanoscale inclusions at the microscale. As a result, this leads to shifts of 100 nm or more in the surface plasmon resonance peak, an order of magnitude greater than any previous work with AuNR composites.

  1. Probabilistic approach for sensing performances of localized surface plasmon resonance biosensors

    NASA Astrophysics Data System (ADS)

    Yang, Heejin; Lee, Wonju; Hwang, Taewon; Kim, Donghyun

    2015-07-01

    We analyze sensing performances of localized surface plasmon resonance biosensors based on the overlap between target distribution and local field intensity produced by silver nanoislands in three detection models of non-specific, non-colocalized, and colocalized detection. The behavior of biomolecules was modeled to follow a probabilistic model using Poisson distribution. The results have found that the colocalized detection achieves the highest overlap signature with the smallest uncertainty and can enhance the limit of detection by more than 10000 times compared to conventional non-specific detection.

  2. Plasmon resonance of gold nanorods for all-optical drawing of liquid droplets

    NASA Astrophysics Data System (ADS)

    de Angelis, M.; Matteini, P.; Ratto, F.; Pini, R.; Coppola, S.; Grilli, S.; Vespini, V.; Ferraro, P.

    2013-10-01

    We present a laser-assisted system for dispensing liquid micro-droplets by near infrared illumination of a pyroelectric crystal functionalized with gold nanorods embedded into polyvinyl alcohol. The non-invasive near infrared source resonates with the plasmon oscillations of the gold nanorods, providing a controlled thermal stimulus able to generate the pyroelectric effect. The resulting electric field interacts electro-hydrodynamically with a liquid reservoir leading to precise drawing of micro-litre droplets. This laser-assisted electro-hydrodynamic technique may open the way to the development of more compact and non-invasive nano-dispensing devices.

  3. Kinetic analysis of nanoparticle-protein interactions using a plasmon waveguide resonance.

    PubMed

    Bahrami, Farshid; Maisonneuve, Mathieu; Meunier, Michel; Montazeri, Arthur O; Kim, Yujin; Kherani, Nazir P; Aitchison, J Stewart; Mojahedi, Mo

    2017-02-01

    A plasmon waveguide resonance (PWR) sensor is proposed for studying the interaction between gold nanoparticles and proteins. The ability of the PWR sensor to operate in both TM and TE Polarizations, i.e. its polarization diversity, facilitates the simultaneous spectroscopy of the nanoparticles surface reactions using both polarizations. The response of each polarization to streptavidin-biotin binding at the surface of gold nanoparticles is investigated in real time. Finally, using the principles of multimode spectroscopy, the nanoparticle's surface reactions are decoupled from the bulk solution refractive index variations. Schematic diagram of the NP-modified PWR sensor.

  4. Plasmonics Resonance Enhanced Active Photothermal Effects of Aluminum and Iron Nanoparticles.

    PubMed

    Chong, Xinyuan; Abboud, Jacques; Zhang, Zhili

    2015-03-01

    Localized Surface Plasmonics Resonance (LSPR) enhanced active photothermal effects of both aluminum nanoparticles (Al NPs) and iron nanoparticles (Fe NPs) are experimentally observed. Photothermally activated motion and ignition by low-energy xenon flash are quantitatively measured. For nanoparticles of comparable sizes, photothermally activated motion height of Fe NPs is about 60% lower than that of Al NPs, while photothermal Minimum Ignition Energy (MIE) of Fe NPs is about 50% lower than that of Al NPs. Joule heating by LSPR enhanced photothermal effects among nanoparticles and subsequently triggered oxidation reactions are found responsible for the motion and ignition of the nanoparticles.

  5. Plasmon resonances on gold nanowires directly drawn in a step-index fiber.

    PubMed

    Tyagi, H K; Lee, H W; Uebel, P; Schmidt, M A; Joly, N; Scharrer, M; Russell, P St J

    2010-08-01

    We report the successful production of high-quality gold wires, with diameters down to 260nm, by direct fiber drawing from a gold-filled fused-silica cane. The stack-and-draw technique makes it straightforward to incorporate a conventional step-index core, adjacent to the gold wire, in the cane. In the drawn fiber, strong coupling of light from the glass core to SPP resonances on the gold wire is observed at specific well-defined wavelengths. Such embedded wires have many potential applications, for example, as nanoscale electrodes, in nonlinear optical plasmonics, and as near-field scanning optical microscope tips.

  6. Surface plasmon resonance biosensors for detection of foodborne pathogens and toxins

    NASA Astrophysics Data System (ADS)

    Homola, Jiří; Hegnerová, Kateřina; Vala, Milan

    2009-02-01

    In the last decade surface plasmon resonance (SPR) biosensors have made great strides both in terms of technology and its applications. SPR biosensors have become a central tool for study of molecular interactions and have been widely used for detection of chemical and biological analytes. Food analysis belongs to major areas of potential applications of SPR biosensors. Therefore, numerous SPR biosensors for detection of analytes implicated in food safety (e.g. pathogens, toxins, drug residues, vitamins, hormones, chemical contaminants, and allergens) have been developed. This paper reviews recent developments in the field of SPR biosensors for food safety, in particular, for detection of foodborne pathogens and toxins.

  7. Angle modulated surface plasmon resonance spectrometer for refractive index sensing with enhanced detection resolution

    NASA Astrophysics Data System (ADS)

    Zhou, Xinlei; Chen, Ke; Li, Li; Peng, Wei; Yu, Qingxu

    2017-01-01

    We design and manufacture an angle modulated surface plasmon resonance (SPR) spectrometer with high detection resolution for refractive index sensing. The presented SPR spectrometer is based on a five-layer Kretchmann configuration. To enhance the sensitivity and resolution of the SPR spectrometer, we introduce a reference beam into the system, which has improved the stability of the system by nearly one order of magnitude. Numerical simulation and experimental study are presented and the results show that a sensitivity of 85 degrees/RIU (refractive index unit) and a good repeatability (standard deviation=3.7×10-6 RIU) have been achieved.

  8. Surface plasmon resonance based fibre optic chemical sensor for the detection of cocaine

    NASA Astrophysics Data System (ADS)

    Nguyen, T. Hien; Sun, Tong; Grattan, Kenneth T. V.

    2016-05-01

    A surface plasmon based fibre-optic chemical sensor for the detection of cocaine has been developed using a molecularly imprinted polymer (MIP) film with embedded gold nanoparticles as the recognition element. The MIP was formed on the layer of gold thin film which was deposited on the surface of a fibre core. The sensing was based on swelling of the MIP film induced by analyte binding that shifted the resonance spectrum toward a shorter wavelength. The sensor exhibited a response to cocaine in the concentration range of 0 - 400 μM in aqueous acetonitrile mixtures. Selectivity for cocaine over other drugs has also been demonstrated.

  9. Applications of Lipid Nanodiscs for the Study of Membrane Proteins by Surface Plasmon Resonance

    PubMed Central

    Trahey, Meg; Li, Mavis Jiarong; Kwon, Hyewon; Woodahl, Erica L.; McClary, Wynton D.

    2015-01-01

    Methods for the initial steps of surface plasmon resonance analysis of membrane proteins incorporated in lipid nanodiscs are described. Several types of BiacoreTM sensor chips are available and require distinct strategies to immobilize proteonanodiscs on the chip surface. The procedures for immobilization on three of these chips (NTA, antibody coupled CM5, and L1) are described and results are demonstrated for a model system with cytochrome P4503A4 (CYP3A4) in nanodiscs binding to a polyclonal anti-CYP3A4 antibody. Advantages and disadvantages of each chip type are considered. PMID:26237675

  10. Detection of aromatic compounds in tequila through the use of surface plasmon resonance.

    PubMed

    Espinosa-Sánchez, Y M; Luna-Moreno, D; Monzón-Hernández, D

    2015-05-10

    For an expert nose, the aroma of a beverage is a fingerprint that can be used to certify its authenticity, distinguish between distillation processes, or even identify the raw material used to fabricate it. In this work, we propose a simple, automatic, and repeatable optical method, which can be used as a first and quick test to authenticate tequila samples. This method is based on the measurement of beam intensity changes, using the surface plasmon resonance technique, operating at a fixed angle. We observed that each tequila, depending on the alcohol content and aging process, produces a specific change in measured intensity level.

  11. A Surface Plasmon Resonance-Based Immunosensors for Sensitive Detection of Heroin

    NASA Astrophysics Data System (ADS)

    Wu, Zhong-cheng; Chen, Wen-ge; Wang, Lian-chao; Ge, Yu; Yu, Cheng-duan; Fang, Ting-jian

    2000-12-01

    A simple technique for sensitive detection of heroin based on surface-plasmon-resonance has been theoretically and experimentally investigated. The experiment was realized by using an anti-MO monoclonal antibody and a morphine (MO)-bovine serum albumin (MO-BSA) conjugate (antigen). The reason for using MO-BSA in the detection of heroine was also discussed. MO-BSA was immobilized on a gold thin film of SPR sensor chip by physical adsorption. The configuration of the device is allowed to be further miniaturized, which is required for the construction of a portable SPR device in the application of in-situ analysis.

  12. Compact surface plasmon resonance biosensor utilizing an injection-molded prism

    NASA Astrophysics Data System (ADS)

    Chen, How-Foo; Chen, Chih-Han; Chang, Yun-Hsiang; Chuang, Hsin-Yuan

    2016-05-01

    Targeting at a low cost and accessible diagnostic device in clinical practice, a compact surface plasmon resonance (SPR) biosensor with a large dynamic range in high sensitivity is designed to satisfy commercial needs in food safety, environmental bio-pollution monitoring, and fast clinical diagnosis. The core component integrates an optical coupler, a sample-loading plate, and angle-tuning reflectors is injection-molded as a free-from prism made of plastic optics. This design makes a matching-oil-free operation during operation. The disposability of this low-cost component ensures testing or diagnosis without cross contamination in bio-samples.

  13. An optical pressure sensor based on π-shaped surface plasmon polariton resonator

    NASA Astrophysics Data System (ADS)

    Duan, Gaoyan; Lang, Peilin; Wang, Lulu; Yu, Li; Xiao, Jinghua

    2016-07-01

    We propose a metal-insulator-metal (MIM) structure which consists of a π-shaped resonator and a surface plasmon polariton (SPP) waveguide. The finite element method (FEM) is employed in the simulation. The results show that this structure forms an optical pressure sensor. The transmission spectra have a redshift with increasing pressure, and the relation between the wavelength shift and the pressure is linear. The nanoscale pressure sensor shows a high sensitivity and may have potential applications in biological and biomedical engineering.

  14. Refractive index measurement of nanoparticles by immersion refractometry based on a surface plasmon resonance sensor

    NASA Astrophysics Data System (ADS)

    Kano, Hiroshi; Iseda, Ayumu; Ohenoja, Katja; Niskanen, Ilpo

    2016-06-01

    Accurate determination of the refractive index of nanoparticles has important ramifications for applications, such as pharmaceuticals, cosmetics, paints, textiles, and inks. We describe a new method to determine the refractive index of nanoparticles by immersion refractometry with a surface plasmon resonance sensor. With this method, the refractive index of the nanoparticles is perfectly matched with that of the surrounding liquid. We demonstrate this method for calcium fluoride nanoparticles that have an average diameter of 100 nm; the results achieve an accuracy of better than 0.002 refractive index units.

  15. Signal enhancement of surface plasmon resonance based on gold nanoparticle-antibody complex for immunoassay.

    PubMed

    Lee, Woochang; Oh, Byung-Keun; Kim, Yong-Wan; Choi, Jeong-Woo

    2006-11-01

    In the immunoassay based on surface plasmon resonance (SPR) system, the signal enhancement was done by means of the conjugate of gold (Au) nanoparticle-antibody fragment. Antibody fragment was prepared for the improved immobilization based on Au-thiol interaction. Through the ellipsometric analysis on surface, the conjugation between Au and antibody fragment was performed in the oriented manner. The optimal fabrication conditions such as concentration and incubation time were determined for the constant size of the fabricated nanoparticle-antibody conjugate. Through the plot of SPR angle difference versus antigen concentration, the linear correlation was achieved, of which the detection limit was 100 fg/ml.

  16. Using surface plasmon resonances to test the durability of silver-copper films.

    PubMed

    Bussjager, R J; Macleod, H A

    1996-09-01

    Silver has high reflectivity in the visible and infrared but cannot be used fully because of its distressing lack of durability. A technique that uses the surface plasmon resonance phenomenon offers a sensitive method for studying the corrosion of silver and assessing improvements. It has been used in the investigation of the effects of flashing a thin layer, approximately 1 nm thick, of copper over silver in an attempt at cathodic protection. Tests include exposing silver and silver-copper films to air, 94% relative humidity, water, and hydrogen sulfide.

  17. A Novel Microfluidic Flow Rate Detection Method Based on Surface Plasmon Resonance Temperature Imaging

    PubMed Central

    Deng, Shijie; Wang, Peng; Liu, Shengnan; Zhao, Tianze; Xu, Shanzhi; Guo, Mingjiang; Yu, Xinglong

    2016-01-01

    A novel microfluidic flow rate detection method based on surface plasmon resonance (SPR) temperature imaging is proposed. The measurement is performed by space-resolved SPR imaging of the flow induced temperature variations. Theoretical simulations and analysis were performed to demonstrate a proof of concept using this approach. Experiments were implemented and results showed that water flow rates within a wide range of tens to hundreds of μL/min could be detected. The flow rate sensor is resistant to disturbances and can be easily integrated into microfluidic lab-on-chip systems. PMID:27347960

  18. Near-field engineering of Fano resonances in a plasmonic assembly for maximizing CARS enhancements.

    PubMed

    He, Jinna; Fan, Chunzhen; Ding, Pei; Zhu, Shuangmei; Liang, Erjun

    2016-02-10

    Surface enhanced coherent anti-Stokes Raman scattering (SECARS) is a sensitive tool and promising for single molecular detection and chemical selective imaging. However, the enhancement factors (EF) were only 10~100 for colloidal silver and gold nanoparticles usually used as SECARS substrates. In this paper, we present a design of SECARS substrate consisting of three asymmetric gold disks and strategies for maximizing the EF by engineering near-field properties of the plasmonic Fano nanoassembly. It is found that the E-field "hot spots" corresponding to three different frequencies involved in SECARS process can be brought to the same spatial locations by tuning incident orientations, giving rise to highly confined SECARS "hot spots" with the EF reaching single-molecule sensitivity. Besides, an even higher EF of SECARS is achieved by introducing double Fano resonances in this plasmonic nanoassembly via further enlarging the sizes of the constituent disks. These findings put an important step forward to the plasmonic substrate design for SECARS as well as for other nonlinear optical processes.

  19. Surface plasmon resonance spectroscopy of single bowtie nano-antennas using a differential reflectivity method

    PubMed Central

    Kaniber, M.; Schraml, K.; Regler, A.; Bartl, J.; Glashagen, G.; Flassig, F.; Wierzbowski, J.; Finley, J. J.

    2016-01-01

    We report on the structural and optical properties of individual bowtie nanoantennas both on glass and semiconducting GaAs substrates. The antennas on glass (GaAs) are shown to be of excellent quality and high uniformity reflected by narrow size distributions with standard deviations for the triangle and gap size of = 4.5 nm = 2.6 nm and = 5.4 nm = 3.8 nm, respectively. The corresponding optical properties of individual nanoantennas studied by differential reflection spectroscopy show a strong reduction of the localised surface plasmon polariton resonance linewidth from 0.21 eV to 0.07 eV upon reducing the antenna size from 150 nm to 100 nm. This is attributed to the absence of inhomogeneous broadening as compared to optical measurements on nanoantenna ensembles. The inter-particle coupling of an individual bowtie nanoantenna, which gives rise to strongly localised and enhanced electromagnetic hotspots, is demonstrated using polarization-resolved spectroscopy, yielding a large degree of linear polarization of ρmax ~ 80%. The combination of highly reproducible nanofabrication and fast, non-destructive and non-contaminating optical spectroscopy paves the route towards future semiconductor-based nano-plasmonic circuits, consisting of multiple photonic and plasmonic entities. PMID:27005986

  20. Green laser excited surface plasmon resonance biosensor utilizing highly sensitive phase interrogation detection

    NASA Astrophysics Data System (ADS)

    Chen, How-Foo; Hsu, Wei-Chen; Wang, Ya-Jung; Yen, Ta-Jen

    2010-04-01

    Surface plasmon resonance (SPR) biosensors have been widely used for dynamical analysis of molecular affinity, bacterium screening, and drug discovery due to its advantages of label-free detection, dynamic interaction analysis, small sample volume, and ultra sensitivity (feasibility of single molecular detection). Recently, SPR biosensing for cell imaging known as SPR microscopy (SPRM) has attracted great attention due to the characteristics of SPR biosensors. However, it is well known that the trends of sensitivity and spatial resolution are opposite to each other: Surface plasmon waves (SPWs) with shorter wavelength which provides higher spatial resolution has less sensitivity. It is known that the spatial resolution of SPRM is limited by the propagation length of surface plasmon wave (SPW) along the metaldielectric interface. SPW excited by 632.8 nm light has the propagation length of 3 um. This length becomes longer when a longer wavelength is selected. While most of SPR biosensors are built with 632.8 nm or longer wavelength for high sensitivity, using 532nm light to excite SPWs is desired for submicron resolution since the propagation length is around 150 nm. Different from current phase interrogation methods, the proposed phase interrogation method is highly sensitive and suitable for CCD imaging. Although it is generally believed that SPWs with wavelength 532nm has poor sensitivity, the experimental result showed that the setup can reach the sensitivity lower than 2×10-6 RIU when sucrose is used as the test sample.

  1. Tuned longitudinal surface plasmon resonance and third-order nonlinear optical properties of gold nanorods.

    PubMed

    Tsutsui, Yushi; Hayakawa, Tomokatsu; Kawamura, Go; Nogami, Masayuki

    2011-07-08

    In order to elucidate the relationship for third-order nonlinear optical properties of anisotropic metal nanoparticles between the incident laser wavelength and surface plasmon resonance (SPR) wavelength, gold nanorods (GNRs) with a tuned longitudinal SPR mode in frequency were prepared by seed-mediated methods with two different surfactants, cetyltrimethylammonium bromide (CTAB) and benzyldimethylammonium chloride (BDAC). The real and imaginary parts of the third-order nonlinear optical susceptibilities χ(3) were examined by near-infrared (800 nm) femtosecond Z-scan and I-scan techniques for various gold sols with SPR wavelengths of 530 nm (spheres), 800 nm (nanorods) and 1000 nm (nanorods), named as 530GNSs, 800GNRs and 1000GNRs, respectively. All the samples showed intrinsically third-order nonlinear optical refractive responses. However, as for the real part of χ(3) for one particle, 800GNRs whose plasmon peak was tuned to the incident laser wavelength exhibited a Reχ(3) value 45 times stronger than 530GNSs. More interestingly, the imaginary part of χ(3) was more greatly influenced at the tuned SPR wavelength. Here we first demonstrate that 800GNRs showed plasmon-enhanced saturable absorption (SA) due to a longitudinal SPR tuned to the incident laser wavelength.

  2. A PMMA-metal lamella grating-based surface plasmon resonance device

    NASA Astrophysics Data System (ADS)

    Lim, Yongjun; Choi, Kyongsik; Kim, Hwi; Kim, Seyoon; Han, Seunghoon; Lee, Byoungho

    2006-02-01

    Recently, a lot of interests have been focused on surface plasmon resonance (SPR), generated by the charge density oscillation existing on the interface between dielectric and metal surface. This particular surface wave has been widely used for sub-wavelength scale photonic circuits, fluorescence microscopy, bio-sensing devices, and photonic display applications. Also, it has a lot of potentials from holographic optical devices to holographic display applications. The measurement of SPR can be simply evaluated by the well-known Kretchmann-Raether attenuated total reflection geometry using angle multiplexing of the incident wave. Based on these concepts, we propose and analyze a plasmon-coupled waveguide and a polymethyl-methacrylate (PMMA) metal thin film grating structure for optical beam coupling and splitting applications. For efficient beam coupling and splitting, we analyze the SPR phenomenon and design plasmon-coupled waveguide structures and the grating structures. To form the PMMA-metal lamella grating structure, we inscribe the grating on the PMMA layer by using excimer laser with the wavelength of 244nm. Then, we deposit gold on the PMMA grating. Finally some experimental results, discussion, and its practical photonic applications are provided.

  3. Near-field engineering of Fano resonances in a plasmonic assembly for maximizing CARS enhancements

    PubMed Central

    He, Jinna; Fan, Chunzhen; Ding, Pei; Zhu, Shuangmei; Liang, Erjun

    2016-01-01

    Surface enhanced coherent anti-Stokes Raman scattering (SECARS) is a sensitive tool and promising for single molecular detection and chemical selective imaging. However, the enhancement factors (EF) were only 10~100 for colloidal silver and gold nanoparticles usually used as SECARS substrates. In this paper, we present a design of SECARS substrate consisting of three asymmetric gold disks and strategies for maximizing the EF by engineering near-field properties of the plasmonic Fano nanoassembly. It is found that the E-field “hot spots” corresponding to three different frequencies involved in SECARS process can be brought to the same spatial locations by tuning incident orientations, giving rise to highly confined SECARS “hot spots” with the EF reaching single-molecule sensitivity. Besides, an even higher EF of SECARS is achieved by introducing double Fano resonances in this plasmonic nanoassembly via further enlarging the sizes of the constituent disks. These findings put an important step forward to the plasmonic substrate design for SECARS as well as for other nonlinear optical processes. PMID:26861192

  4. Surface plasmon resonance spectroscopy of single bowtie nano-antennas using a differential reflectivity method

    NASA Astrophysics Data System (ADS)

    Kaniber, M.; Schraml, K.; Regler, A.; Bartl, J.; Glashagen, G.; Flassig, F.; Wierzbowski, J.; Finley, J. J.

    2016-03-01

    We report on the structural and optical properties of individual bowtie nanoantennas both on glass and semiconducting GaAs substrates. The antennas on glass (GaAs) are shown to be of excellent quality and high uniformity reflected by narrow size distributions with standard deviations for the triangle and gap size of = 4.5 nm = 2.6 nm and = 5.4 nm = 3.8 nm, respectively. The corresponding optical properties of individual nanoantennas studied by differential reflection spectroscopy show a strong reduction of the localised surface plasmon polariton resonance linewidth from 0.21 eV to 0.07 eV upon reducing the antenna size from 150 nm to 100 nm. This is attributed to the absence of inhomogeneous broadening as compared to optical measurements on nanoantenna ensembles. The inter-particle coupling of an individual bowtie nanoantenna, which gives rise to strongly localised and enhanced electromagnetic hotspots, is demonstrated using polarization-resolved spectroscopy, yielding a large degree of linear polarization of ρmax ~ 80%. The combination of highly reproducible nanofabrication and fast, non-destructive and non-contaminating optical spectroscopy paves the route towards future semiconductor-based nano-plasmonic circuits, consisting of multiple photonic and plasmonic entities.

  5. Near-field engineering of Fano resonances in a plasmonic assembly for maximizing CARS enhancements

    NASA Astrophysics Data System (ADS)

    He, Jinna; Fan, Chunzhen; Ding, Pei; Zhu, Shuangmei; Liang, Erjun

    2016-02-01

    Surface enhanced coherent anti-Stokes Raman scattering (SECARS) is a sensitive tool and promising for single molecular detection and chemical selective imaging. However, the enhancement factors (EF) were only 10~100 for colloidal silver and gold nanoparticles usually used as SECARS substrates. In this paper, we present a design of SECARS substrate consisting of three asymmetric gold disks and strategies for maximizing the EF by engineering near-field properties of the plasmonic Fano nanoassembly. It is found that the E-field “hot spots” corresponding to three different frequencies involved in SECARS process can be brought to the same spatial locations by tuning incident orientations, giving rise to highly confined SECARS “hot spots” with the EF reaching single-molecule sensitivity. Besides, an even higher EF of SECARS is achieved by introducing double Fano resonances in this plasmonic nanoassembly via further enlarging the sizes of the constituent disks. These findings put an important step forward to the plasmonic substrate design for SECARS as well as for other nonlinear optical processes.

  6. Switching Plasmons: Gold Nanorod-Copper Chalcogenide Core-Shell Nanoparticle Clusters with Selectable Metal/Semiconductor NIR Plasmon Resonances.

    PubMed

    Muhammed, Madathumpady Abubaker Habeeb; Döblinger, Markus; Rodríguez-Fernández, Jessica

    2015-09-16

    Exerting control over the near-infrared (NIR) plasmonic response of nanosized metals and semiconductors can facilitate access to unexplored phenomena and applications. Here we combine electrostatic self-assembly and Cd(2+)/Cu(+) cation exchange to obtain an anisotropic core-shell nanoparticle cluster (NPC) whose optical properties stem from two dissimilar plasmonic materials: a gold nanorod (AuNR) core and a copper selenide (Cu(2-x)Se, x ≥ 0) supraparticle shell. The spectral response of the AuNR@Cu2Se NPCs is governed by the transverse and longitudinal plasmon bands (LPB) of the anisotropic metallic core, since the Cu2Se shell is nonplasmonic. Under aerobic conditions the shell undergoes vacancy doping (x > 0), leading to the plasmon-rich NIR spectrum of the AuNR@Cu(2-x)Se NPCs. For low vacancy doping levels the NIR optical properties of the dually plasmonic NPCs are determined by the LPBs of the semiconductor shell (along its major longitudinal axis) and of the metal core. Conversely, for high vacancy doping levels their NIR optical response is dominated by the two most intense plasmon modes from the shell: the transverse (along the shortest transversal axis) and longitudinal (along the major longitudinal axis) modes. The optical properties of the NPCs can be reversibly switched back to a purely metallic plasmonic character upon reversible conversion of AuNR@Cu(2-x)Se into AuNR@Cu2Se. Such well-defined nanosized colloidal assemblies feature the unique ability of holding an all-metallic, a metallic/semiconductor, or an all-semiconductor plasmonic response in the NIR. Therefore, they can serve as an ideal platform to evaluate the crosstalk between plasmonic metals and plasmonic semiconductors at the nanoscale. Furthermore, their versatility to display plasmon modes in the first, second, or both NIR windows is particularly advantageous for bioapplications, especially considering their strong absorbing and near-field enhancing properties.

  7. Characterization of a variable angle reflection Fourier transform infrared accessory modified for surface plasmon resonance spectroscopy.

    PubMed

    Menegazzo, Nicola; Kegel, Laurel L; Kim, Yoon-Chang; Booksh, Karl S

    2010-10-01

    The Harrick AutoSeagull variable angle reflection accessory for Fourier transform infrared (FT-IR) spectrometers provides access to various spectroscopic techniques in a highly flexible platform. In particular, its ability to perform total internal reflection measurements is of interest because it also forms the basis for surface plasmon resonance (SPR) spectroscopy in prism-based configurations. The work presented here discusses the modification of the AutoSeagull to perform SPR spectroscopy, allowing for easy incorporation of the technique into most common FT-IR spectrometers. The wavelength dependency of the dielectric constant of the plasmon-supporting metal (in our case, gold) is largely responsible for the sensitivity attributed to changes in the sample's refractive index (RI) monitored by SPR spectroscopy. Furthermore, the optical properties of gold are such that when near-infrared (NIR) and/or mid-infrared (mid-IR) wavelengths are used to excite surface plasmons, higher sensitivities to RI changes are experienced compared to surface plasmons excited with visible wavelengths. The result is that in addition to instrumental simplicity, SPR analysis on FT-IR spectrometers, as permitted by the modified AutoSeagull, also benefits from the wavelength ranges accessible. Adaptation of the AutoSeagull to SPR spectroscopy involved the incorporation of slit apertures to minimize the angular spread reaching the detector, resulting in sharper SPR "dips" but at the cost of noisier spectra. In addition, discussion of the system's analytical performance includes comparison of dip quality as a function of slit size, tailoring of the dip minima location with respect to incident angle, and sensitivity to bulk RI changes.

  8. Integrated optical gyroscope using active long-range surface plasmon-polariton waveguide resonator.

    PubMed

    Zhang, Tong; Qian, Guang; Wang, Yang-Yang; Xue, Xiao-Jun; Shan, Feng; Li, Ruo-Zhou; Wu, Jing-Yuan; Zhang, Xiao-Yang

    2014-01-24

    Optical gyroscopes with high sensitivity are important rotation sensors for inertial navigation systems. Here, we present the concept of integrated resonant optical gyroscope constructed by active long-range surface plasmon-polariton (LRSPP) waveguide resonator. In this gyroscope, LRSPP waveguide doped gain medium is pumped to compensate the propagation loss, which has lower pump noise than that of conventional optical waveguide. Peculiar properties of single-polarization of LRSPP waveguide have been found to significantly reduce the polarization error. The metal layer of LRSPP waveguide is electro-optical multiplexed for suppression of reciprocal noises. It shows a limited sensitivity of ~10(-4) deg/h, and a maximum zero drift which is 4 orders of magnitude lower than that constructed by conventional single-mode waveguide.

  9. Tailoring the surface plasmon resonance of embedded silver nanoparticles by combining nano- and femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Doster, J.; Baraldi, G.; Gonzalo, J.; Solis, J.; Hernandez-Rueda, J.; Siegel, J.

    2014-04-01

    We demonstrate that the broad surface plasmon resonance (SPR) of a single layer of near-coalescence silver nanoparticles (NPs), embedded in a dielectric matrix can be tailored by irradiation with a single nanosecond laser pulse into a distribution featuring a sharp resonance at 435 nm. Scanning electron microscopy studies reveal the underlying mechanism to be a transformation into a distribution of well-separated spherical particles. Additional exposure to multiple femtosecond laser pulses at 400 nm or 800 nm wavelength induces polarization anisotropy of the SPR, with a peak shift that increases with laser wavelength. The spectral changes are measured in-situ, employing reflection and transmission micro-spectroscopy with a lateral resolution of 4 μm. Spectral maps as a continuous function of local fluence can be readily produced from a single spot. The results open exciting perspectives for dynamically tuning and switching the optical response of NP systems, paving the way for next-generation applications.

  10. Fano resonances and electromagnetically induced transparency in silicon waveguides loaded with plasmonic nanoresonators

    NASA Astrophysics Data System (ADS)

    Ortuño, Rubén; Cortijo, Mario; Martínez, Alejandro

    2017-02-01

    The fundamental electric dipolar resonance of metallic nanostrips placed on top of a dielectric waveguide can be excited via evanescent wave coupling, thus giving rise to broad dips in the transmission spectrum of the waveguide. Here we show via numerical simulations that narrower and steeper Fano-like resonances can be obtained by asymmetrically coupling in the near field a larger nanostrip—supporting an electric quadrupole in the frequency regime of interest—to the original, shorter nanostrip. Under certain conditions, the spectral response corresponding to the electromagnetically induced transparency phenomenon is observed. We suggest that this hybrid plasmonic-photonic approach could be especially relevant for sensing or all-optical switching applications in a photonic integrated platform such as silicon photonics.

  11. A highly temperature-sensitive photonic crystal fiber based on surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Wang, Famei; Lv, Jingwei; Sun, Tao; Liu, Qiang; Fu, Changfeng; Mu, Haiwei; Chu, Paul K.

    2016-01-01

    A novel temperature sensor comprising a photonic crystal fiber (PCF) is investigated based on surface plasmon resonance (SPR). The finite element method (FEM) is used to determine the temperature sensitivity of the PCF consisting of different concentrations of the analyte. Coating the sensor with a gold layer on the wall of the liquid channel not only overcomes experimental challenges, but also enhances the temperature sensitivity. The simulation results show that the SPR spectra blue-shift with increasing temperature and the resonance wavelength and confinement loss depend on the thickness of the gold layer. The sensor exhibits remarkable temperature sensitivity up to 3080 pm/°C with a corresponding resolution of 0.01325 °C.

  12. Extreme optical chirality of plasmonic nanohole arrays due to chiral Fano resonance

    NASA Astrophysics Data System (ADS)

    Kondratov, A. V.; Gorkunov, M. V.; Darinskii, A. N.; Gainutdinov, R. V.; Rogov, O. Y.; Ezhov, A. A.; Artemov, V. V.

    2016-05-01

    We study the physical origin of extreme optical chirality of subwavelength arrays of chiral holes in metal. We reconstruct the nanoscale relief of the hole arrays by the atomic-force microscopy and post-process the data to acquire an average unit-cell shape clear of noise and defects. For this shape, we perform the electromagnetic finite difference time domain simulations that reproduce all important features observed by the light-transmission experiments, including the notably strong circular dichroism and optical activity covering the whole range of possible values. To interpret the simulation results, we develop a chiral coupled-mode model which yields analytical expressions that fit accurately the numerical data in a broad wavelength range. Our conclusions undoubtedly link the extreme optical chirality to the plasmon resonances of chiral holes and the associated chiral Fano-type transmission resonance.

  13. Surface plasmon resonance imaging detection of silver nanoparticle-tagged immunoglobulin

    PubMed Central

    Paul, Sharmistha; Paul, Deepen; Fern, George R.; Ray, Asim K.

    2011-01-01

    The detection sensitivity of silver nanoparticle (AgNP)-tagged goat immunoglobulin G (gIgG) microarrays was investigated by studying surface plasmon resonance (SPR) images captured in the visible wavelength range with the help of a Kretchmann-configured optical coupling set-up. The functionalization of anti-gIgG molecules on the AgNP surface was studied using transmission electron microscopy, photon correlation measurements and UV–visible absorption spectroscopy. A value of 1.3 × 107 M−1 was obtained for the antibody–antigen binding constant by monitoring the binding events at a particular resonance wavelength. The detection limit of this SPR imaging instrument is 6.66 nM of gIgG achieved through signal enhancement by a factor of larger than 4 owing to nanoparticle tagging with the antibody. PMID:21325318

  14. Detection of Salmonella enteritidis Using a Miniature Optical Surface Plasmon Resonance Biosensor

    NASA Astrophysics Data System (ADS)

    Son, J. R.; Kim, G.; Kothapalli, A.; Morgan, M. T.; Ess, D.

    2007-04-01

    The frequent outbreaks of foodborne illness demand rapid detection of foodborne pathogens. Unfortunately, conventional methods for pathogen detection and identification are labor-intensive and take days to complete. Biosensors have shown great potential for the rapid detection of foodborne pathogens. Surface plasmon resonance (SPR) sensors have been widely adapted as an analysis tool for the study of various biological binding reactions. SPR biosensors could detect antibody-antigen bindings on the sensor surface by measuring either a resonance angle or refractive index value. In this study, the feasibility of a miniature SPR sensor (Spreeta, TI, USA) for detection of Salmonella enteritidis has been evaluated. Anti-Salmonella antibodies were immobilized on the gold sensor surface by using neutravidin. Salmonella could be detected by the Spreeta biosensor at concentrations down to 105 cfu/ml.

  15. Integrated optical gyroscope using active Long-range surface plasmon-polariton waveguide resonator

    PubMed Central

    Zhang, Tong; Qian, Guang; Wang, Yang-Yang; Xue, Xiao-Jun; Shan, Feng; Li, Ruo-Zhou; Wu, Jing-Yuan; Zhang, Xiao-Yang

    2014-01-01

    Optical gyroscopes with high sensitivity are important rotation sensors for inertial navigation systems. Here, we present the concept of integrated resonant optical gyroscope constructed by active long-range surface plasmon-polariton (LRSPP) waveguide resonator. In this gyroscope, LRSPP waveguide doped gain medium is pumped to compensate the propagation loss, which has lower pump noise than that of conventional optical waveguide. Peculiar properties of single-polarization of LRSPP waveguide have been found to significantly reduce the polarization error. The metal layer of LRSPP waveguide is electro-optical multiplexed for suppression of reciprocal noises. It shows a limited sensitivity of ~10−4 deg/h, and a maximum zero drift which is 4 orders of magnitude lower than that constructed by conventional single-mode waveguide. PMID:24458281

  16. Triply surface-plasmon resonant four-wave mixing imaging of gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Masia, Francesco; Langbein, Wolfgang; Watson, Peter; Borri, Paola

    2011-03-01

    We have developed a novel multiphoton microscopy technique not relying on (and hence not limited by) fluorescence emission, which exploits the third-order nonlinearity called four-wave mixing of gold nanoparticles in resonance with their surface Plasmon. The coherent, transient and resonant nature of this signal allows its detection free from backgrounds that limit other contrast methods for gold nanoparticles. We show detection of single 10nm gold nanoparticles with low excitation intensities, corresponding to negligible average thermal heating. Owing to the the third-order nonlinearity we measure a transversal and axial resolution of 140nm and 470nm respectively, better than the one-photon diffraction limit. We also show high-contrast imaging of gold-labels down to 5nm size in Golgi structures of HepG2 cells at useful imaging speeds (10 kHz pixel rate). Thermal dissociation of gold nanoparticles from their bonding sites when varying the excitation intensity is also investigated.

  17. Tunable Plasmonic Band-Pass Filter with Dual Side-Coupled Circular Ring Resonators

    PubMed Central

    Liu, Dongdong; Wang, Jicheng; Zhang, Feng; Pan, Yuewu; Lu, Jian; Ni, Xiaowu

    2017-01-01

    A wavelength band-pass filter with asymmetric dual circular ring resonators in a metal-insulator-metal (MIM) structure is proposed and numerically simulated. For the interaction of the local discrete state and the continuous spectrum caused by the side-coupled resonators and the baffle, respectively, the transmission spectrum exhibits a sharp and asymmetric profile. By adjusting the radius and material imbedded in one ring cavity, the off-to-on plasmon-induced absorption (PIA) optical response can be tunable achieved. In addition, the structure can be easily extended to other similar compact structures to realize the filtering task. Our structures have important potential applications for filters and sensors at visible and near-infrared regions. PMID:28335398

  18. Analysis of surface plasmon resonance with Goos-Hanchen shift using FDTD method

    NASA Astrophysics Data System (ADS)

    Oh, Geum-Yoon; Kim, Doo-Gun; Kim, Hong-Seung; Choi, Young-Wan

    2009-02-01

    The Goos-Hanchen (GH) shift is observed from phase transition of the reflected light. However, the reported Artmann's equation is difficult to apply to drastic phase change of the critical and resonance angles because this equation is solved by differential of the phase shift. Therefore, the GH shift can be obtained from the structure optimized by the finite-difference time-domain method. In the surface plasmon resonance (SPR) phenomenon, positive and negative lateral shifts may result from the variation of incidence angle. The GH shift is very important to exactly detect the output power of the micro-size SPR sensor. The accurate positive and negative lateral shifts of -0.49 and +1.46 μm are obtained on the SPR with the incidence angles of 44.4° and 47°, respectively.

  19. Enhancing sensitivity for surface plasmon resonance biosensors using periodic structures and spectro-angular image analysis

    NASA Astrophysics Data System (ADS)

    Alleyne, Colin James

    Surface plasmon resonance (SPR) is a phenomena whereby photons are made to couple energy to a surface electron density wave traveling on a metal-dielectric interface. The coupling occurs at a specific energy and momentum, collectively referred to as the resonance condition, causing a dip in the reflected light. The characteristics of the dip are a function of the material properties at the interface; therefore monitoring the dip provides information about the local surface environment. Recent years have seen a push in SPR technology towards miniaturization, increased sensitivity, high throughput and multimodal approaches. This thesis focuses on two methods for improving the performance of SPR biosensors. First, SPR sensitivity is improved through the use of a surface plasmon bandgap structure. It is shown here that operating an SPR biosensor in angular interrogation mode near the edge of such a bandgap will result in a six fold increase in the sensitivity compared to SPR on a flat metallic surface under the same conditions. Second, a method for improving the detection limit is shown using a novel data analysis technique based on image processing. A multimodal surface plasmon interrogation technique is used to create a 2-D image of the spectro-angular dispersion from a surface; which is then used to extract information about the surface environment using an eigenvector analysis technique developed to exploit the spectro-angular information. Using the novel eigenvector technique, designated as the Double Projection Method (DPM), on the spectro-angular data results in refractive index estimates over a wide dynamic range with a theoretical detection limit of 5x10-9 refractive index units (RIU); which is superior to the current highest sensitivity phase-based methods. Experimental work shows the DPM method capable of monitoring biomolecular interactions with small molecular weight reactants (˜400 Daltons) in real-time with an achieved resolution of 2x10-6 RIU.

  20. Analysis of Surface Plasmon Resonance Curves with a Novel Sigmoid-Asymmetric Fitting Algorithm.

    PubMed

    Jang, Daeho; Chae, Geunhyoung; Shin, Sehyun

    2015-09-30

    The present study introduces a novel curve-fitting algorithm for surface plasmon resonance (SPR) curves using a self-constructed, wedge-shaped beam type angular interrogation SPR spectroscopy technique. Previous fitting approaches such as asymmetric and polynomial equations are still unsatisfactory for analyzing full SPR curves and their use is limited to determining the resonance angle. In the present study, we developed a sigmoid-asymmetric equation that provides excellent curve-fitting for the whole SPR curve over a range of incident angles, including regions of the critical angle and resonance angle. Regardless of the bulk fluid type (i.e., water and air), the present sigmoid-asymmetric fitting exhibited nearly perfect matching with a full SPR curve, whereas the asymmetric and polynomial curve fitting methods did not. Because the present curve-fitting sigmoid-asymmetric equation can determine the critical angle as well as the resonance angle, the undesired effect caused by the bulk fluid refractive index was excluded by subtracting the critical angle from the resonance angle in real time. In conclusion, the proposed sigmoid-asymmetric curve-fitting algorithm for SPR curves is widely applicable to various SPR measurements, while excluding the effect of bulk fluids on the sensing layer.

  1. Sensing Plasmon-Resonant Nanorods in Tissue with Optical Coherence Tomography

    NASA Astrophysics Data System (ADS)

    Oldenburg, Amy

    2009-11-01

    Gold nanoparticles (GNPs) are of high interest for biomedical imaging and photothermal therapy due to their plasmon-resonant nature. However, their utility is limited by transport and targeting to the disease of interest after administration in the living body. Optical coherence tomography can image the distribution of GNPs on the micro- to meso-scale, leading toward a better understanding of these limiting factors. Plasmon-resonant nanorods provide strong optical absorption at near-infrared wavelengths, and are studied using an optical coherence tomography system based on a broadband laser centered at 800nm. The ability to sense GNPs against a biological tissue background is treated as a sensing problem with parameters including the nanorod volume and aspect ratio, optical detection metrics including extinction, a new backscattering albedo metric based on the ratio of backscattering to extinction, and spectroscopic analysis. A key element of this analysis is determining the native tissue optical response, optical signal noise, and spatial heterogeneity before addition of the GNPs. Experiments are performed in skin-like tissue phantoms where a sensitivity of 30ppm is found. Experiments in excised human mammary tumors reveal additional challenges for imaging in real tissues, and the results of various processing techniques are compared.

  2. Integrated electrokinetic sample focusing and surface plasmon resonance imaging system for measuring biomolecular interactions.

    PubMed

    Krishnamoorthy, Ganeshram; Carlen, Edwin T; Kohlheyer, Dietrich; Schasfoort, Richard B M; van den Berg, Albert

    2009-03-01

    Label-free biomolecular binding measurement methods, such as surface plasmon resonance (SPR), are becoming increasingly more important for the estimation of real-time binding kinetics. Recent advances in surface plasmon resonance imaging (iSPR) are emerging for label-free microarray-based assay applications, where multiple biomolecular interactions can be measured simultaneously. However, conventional iSPR microarray systems rely on protein printing techniques for ligand immobilization to the gold imaging surface and external pumps for analyte transport. In this article, we present an integrated microfluidics and iSPR platform that uses only electrokinetic transport and guiding of ligands and analytes and, therefore, requires only electrical inputs for sample transport. An important advantage of this new approach, compared to conventional systems, is the ability to direct a single analyte to a specific ligand location in the microarray, which can facilitate analysis parallelization. Additionally, this simple approach does not require complicated microfluidic channel arrangements, external pumps, or valves. As a demonstration, kinetics and affinity have been extracted from measured binding responses of human IgG and goat antihuman IgG using a simple 1:1 model and compared to responses measured with conventional pressure driven analyte transport. The measured results indicate similar binding kinetics and affinity between the electrokinetic and pressure-driven sample manipulation methods and no cross contamination to adjacent measurement locations has been observed.

  3. Electrochemical surface plasmon resonance biosensor for study of DNA desorption and hybridization

    NASA Astrophysics Data System (ADS)

    Ferrari, Luca; Šípová, Hana; Tichý, Ivo; Chadt, Karel; Homola, Jiri

    2013-05-01

    We report a system, which combines electrochemical and surface plasmon resonance (SPR) techniques on the same sensing chip. Each channel of a four-channel laboratory SPR sensor is supplemented with two planar gold electrodes (the reference and the counter electrodes), whereas the gold layer of SPR chip is used as the working electrode. A custom electronics enables to set an arbitrary potential between the reference and working electrodes and to measure the current flow between the counter and the working electrodes. Information from standard electrochemical techniques, i.e. cyclovoltammetry and chronoamperometry can be acquired with the system while simultaneously monitoring the shift in the surface plasmon resonance. The electrochemical SPR biosensor was used to study desorption of thiolated DNA probes with a negative potential. By comparing the acquired electrochemical and SPR signals, we show that DNA probes as well as a monolayer of alkanethiols can be desorbed by applying negative potentials to the SPR chip surface. Moreover, it is shown that the DNA probes can be reabsorbed on the SPR sensor surface and the complementary DNA can be detected without loss in detection sensitivity.

  4. Two-dimensional ultrathin gold film composed of steadily linked dense nanoparticle with surface plasmon resonance

    PubMed Central

    2012-01-01

    Background Noble metallic nanoparticles have prominent optical local-field enhancement and light trapping properties in the visible light region resulting from surface plasmon resonances. Results We investigate the optical spectral properties and the surface-enhanced Raman spectroscopy of two-dimensional distinctive continuous ultrathin gold nanofilms. Experimental results show that the one- or two-layer nanofilm obviously increases absorbance in PEDOT:PSS and P3HT:PCBM layers and the gold nanofilm acquires high Raman-enhancing capability. Conclusions The fabricated novel structure of the continuous ultrathin gold nanofilms possesses high surface plasmon resonance properties and boasts a high surface-enhanced Raman scattering (SERS) enhancement factor, which can be a robust and cost-efficient SERS substrate. Interestingly, owing to the distinctive morphology and high light transmittance, the peculiar nanofilm can be used in multilayer photovoltaic devices to trap light without affecting the physical thickness of solar photovoltaic absorber layers and yielding new options for solar cell design. PMID:23259927

  5. Plasmonic mode interferences and Fano resonances in Metal-Insulator- Metal nanostructured interface

    PubMed Central

    Nicolas, Rana; Lévêque, Gaëtan; Marae-Djouda, Joseph; Montay, Guillame; Madi, Yazid; Plain, Jérôme; Herro, Ziad; Kazan, Michel; Adam, Pierre-Michel; Maurer, Thomas

    2015-01-01

    Metal-insulator-metal systems exhibit a rich underlying physics leading to a high degree of tunability of their spectral properties. We performed a systematic study on a metal-insulator-nanostructured metal system with a thin 6 nm dielectric spacer and showed how the nanoparticle sizes and excitation conditions lead to the tunability and coupling/decoupling of localized and delocalized plasmonic modes. We also experimentally evidenced a tunable Fano resonance in a broad spectral window 600 to 800 nm resulting from the interference of gap modes with white light broad band transmitted waves at the interface playing the role of the continuum. By varying the incident illumination angle shifts in the resonances give the possibility to couple or decouple the localized and delocalized modes and to induce a strong change of the asymmetric Fano profile. All these results were confirmed with a crossed comparison between experimental and theoretical measurements, confirming the nature of different modes. The high degree of control and tunability of this plasmonically rich system paves the way for designing and engineering of similar systems with numerous applications. In particular, sensing measurements were performed and a figure of merit of 3.8 was recorded ranking this sensor among the highest sensitive in this wavelength range. PMID:26399425

  6. A low cost surface plasmon resonance biosensor using a laser line generator

    NASA Astrophysics Data System (ADS)

    Chen, Ruipeng; Wang, Manping; Wang, Shun; Liang, Hao; Hu, Xinran; Sun, Xiaohui; Zhu, Juanhua; Ma, Liuzheng; Jiang, Min; Hu, Jiandong; Li, Jianwei

    2015-08-01

    Due to the instrument designed by using a common surface plasmon resonance biosensor is extremely expensive, we established a portable and cost-effective surface plasmon resonance biosensing system. It is mainly composed of laser line generator, P-polarizer, customized prism, microfluidic cell, and line Charge Coupled Device (CCD) array. Microprocessor PIC24FJ128GA006 with embedded A/D converter, communication interface circuit and photoelectric signal amplifier circuit are used to obtain the weak signals from the biosensing system. Moreover, the line CCD module is checked and optimized on the number of pixels, pixels dimension, output amplifier and the timing diagram. The micro-flow cell is made of stainless steel with a high thermal conductivity, and the microprocessor based Proportional-Integral-Derivative (PID) temperature-controlled algorithm was designed to keep the constant temperature (25 °C) of the sample solutions. Correspondingly, the data algorithms designed especially to this biosensing system including amplitude-limiting filtering algorithm, data normalization and curve plotting were programmed efficiently. To validate the performance of the biosensor, ethanol solution samples at the concentrations of 5%, 7.5%, 10%, 12.5% and 15% in volumetric fractions were used, respectively. The fitting equation ΔRU = - 752987.265 + 570237.348 × RI with the R-Square of 0.97344 was established by delta response units (ΔRUs) to refractive indexes (RI). The maximum relative standard deviation (RSD) of 4.8% was obtained.

  7. Plasmon resonance enhanced temperature-dependent photoluminescence of Si-V centers in diamond

    SciTech Connect

    Cheng, Shaoheng; Song, Jie; Wang, Qiliang; Liu, Junsong; Li, Hongdong; Zhang, Baolin

    2015-11-23

    Temperature dependent optical property of diamond has been considered as a very important factor for realizing high performance diamond-based optoelectronic devices. The photoluminescence feature of the zero phonon line of silicon-vacancy (Si-V) centers in Si-doped chemical vapor deposited single crystal diamond (SCD) with localized surface plasmon resonance (LSPR) induced by gold nanoparticles has been studied at temperatures ranging from liquid nitrogen temperature to 473 K, as compared with that of the SCD counterpart in absence of the LSPR. It is found that with LSPR the emission intensities of Si-V centers are significantly enhanced by factors of tens and the magnitudes of the redshift (width) of the emissions become smaller (narrower), in comparison with those of normal emissions without plasmon resonance. More interestingly, these strong Si-V emissions appear remarkably at temperatures up to 473 K, while the spectral feature was not reported in previous studies on the intrinsic Si-doped diamonds when temperatures are higher than room temperature. These findings would lead to reaching high performance diamond-based devices, such as single photon emitter, quantum cryptography, biomarker, and so forth, working under high temperature conditions.

  8. Immobilization of human papillomavirus DNA probe for surface plasmon resonance imaging

    NASA Astrophysics Data System (ADS)

    Chong, Xinyuan; Ji, Yanhong; Ma, Suihua; Liu, Le; Liu, Zhiyi; Li, Yao; He, Yonghong; Guo, Jihua

    2009-08-01

    Human papillomavirus (HPV) is a kind of double-stranded DNA virus whose subspecies have diversity. Near 40 kinds of subspecies can invade reproductive organ and cause some high risk disease, such as cervical carcinoma. In order to detect the type of the subspecies of the HPV DNA, we used the parallel scan spectral surface plasmon resonance (SPR) imaging technique, which is a novel type of two- dimensional bio-sensing method based on surface plasmon resonance and is proposed in our previous work, to study the immobilization of the HPV DNA probes on the gold film. In the experiment, four kinds of the subspecies of the HPV DNA (HPV16, HPV18, HPV31, HPV58) probes are fixed on one gold film, and incubate in the constant temperature condition to get a HPV DNA probe microarray. We use the parallel scan spectral SPR imaging system to detect the reflective indices of the HPV DNA subspecies probes. The benefits of this new approach are high sensitive, label-free, strong specificity and high through-put.

  9. Design and analysis of a photonic crystal fiber based polarization filter using surface plasmon resonance

    NASA Astrophysics Data System (ADS)

    Yogalakshmi, S.; Selvendran, S.; Sivanantha Raja, A.

    2016-05-01

    A photonic crystal fiber with an active metal nanowire is proposed to act as a polarization filter based on the principle of plasmonic resonance. The light launched into the silica core gets coupled to gold wire inducing surface plasmon resonance, filtering one of the two orthogonally polarized light waves in the third optical communication window. This polarization filtering characteristic is analyzed using the finite element method. The change in the performance behaviour of the proposed filter is investigated by increasing the number of embedded gold wires, altering their positions and varying the diameter of gold wire. It is found that enhanced absorption of the core guided mode is achieved by replacing the filled metal nanowire with a metal coating around the air hole. Filtering of any or both polarizations can be attained by suitably positioning the metal wires. Confinement loss as high as 348.55 and 302 dB cm-1 for y-polarized and x-polarized lights respectively are attained at 1.52 and 1.56 μm respectively for single gold wire. The filter acts as a single polarization filter filtering x-polarized light with a confinement loss value of 187.67 dB cm-1 when two gold nanowires are placed adjacently. The same structure acts as the filter for y-polarized light by employing gold coating exhibiting an increased confinement loss of 406.34 dB cm-1 at 1.64 μm.

  10. Enhancing the sensitivity of localized surface plasmon resonance (LSPR) biosensors using nanorods and DNA aptamers

    NASA Astrophysics Data System (ADS)

    Chuang, Po-Chun; Liao, Pei-Chen; Chen, Yih-Fan

    2015-03-01

    Localized surface plasmon resonance (LSPR) biosensors have drawn much attention for their promising application in point-of-care diagnostics. While surface plasmon resonance (SPR) biosensing systems have been well developed, LSPR systems have the advantages of simpler and more compact setups. The LSPR peak shifts caused by the binding of molecules to the LSPR substrates, however, are usually smaller than 1 nm if no signal amplification mechanism is used. When using nanoparticles to enhance the sensitivity of LSPR biosensors, because of the short field penetration depth, the nanoparticles should be very close to the LSPR substrate to induce significant shifts in the LSPR peak position. In this study, we used DNA aptamers and gold nanorods to significantly increase the change in the LSPR peak position with the concentration of the target molecules. We have successfully used the proposed mechanism to detect 0.1 nM interferongamma (IFN-γ), a biomarker related to the diagnosis of latent tuberculosis infection. The calibration curves obtained in pure buffers and serum-containing buffers show that accurate detection can be achieved even when the sample is from complex biological fluids such as serum. Because of the enhancement in the sensitivity by the proposed sensing scheme, it is possible to use a low-cost spectrometer to build a LSPR biosensing system.

  11. Resonant electron emission of silver spheroids induced by laser surface plasmon excitation

    NASA Astrophysics Data System (ADS)

    Monchicourt, P.; Raynaud, M.; Saringar, H.; Kupersztych, J.

    1997-07-01

    Laser excitation of surface plasmons on a silver granular surface has been studied as a function of light frequency. Both light absorption and electron emission have been measured by varying continuously the wavelength between 275 and 700 nm. Resonance effects at the Fröhlich frequencies of the silver spheroids are displayed and a correlation between absorption and emission is clearly exhibited. The lux - ampere characteristics performed at selected increasing wavelengths display slopes with integer orders, indicating that the emission process remains a photoeffect even in the presence of a surface-plasmon resonance. The photoemission process shows net switches of these slopes that turn from linear into quadratic and then cubic integer values. The position of the first switch yields 0953-8984/9/27/008/img1 eV for the work function of the granular surface. The position of the second switch defines the threshold energy for the two-photon emission process, which is found to differ significantly from the expected photon minimum energy 0953-8984/9/27/008/img2.

  12. Optical immunosensor for endocrine disruptor nanolayer detection by surface plasmon resonance imaging

    NASA Astrophysics Data System (ADS)

    Karabchevsky, Alina; Tsapovsky, Lev; Marks, Robert S.; Abdulhalim, Ibrahim

    2011-10-01

    Endocrine disrupting compounds (EDCs) such as bisphenol A (BPA) and female hormone Estrone are especially prevalent in surface and waste-waters in nano-molar concentrations and therefore, there is a need for sensitive analytical device for their monitoring. We have designed a miniature, low cost and fast surface plasmon resonance (SPR) imaging liquid sensor based on the angular interrogation using Kretschmann configuration with diverged incident monochromatic light. During this paper we present a surface plasmon resonance imaging (SPRI) biosensor to detect EDCs such as BPA and estrone. A pattern of SPR line which is dark intensity line on bright area was reflected at angles range depending on the dielectric constant of the analye: Rabbit Anti-Estrone polyclonal IgG + Estrone 11-MUA attached to the silver or non-specific sensing of BPA in water with nanoprecision. For analyzing the SPR signals we used an efficient detection algorithm based on Radon Transform with less sensitivity to laser speckle noise and nonuniformity of the illumination.

  13. Localized Surface Plasmon Resonance properties of copper nano-clusters: A theoretical study of size dependence

    NASA Astrophysics Data System (ADS)

    Ziashahabi, A.; Ghodselahi, T.; Heidari saani, M.

    2013-07-01

    Density functional theory (DFT) calculations are carried out to study the electronic, structural stability and Localized Surface Plasmon Resonance (LSPR) properties of copper nano-clusters. These nano-clusters consisted of 14, 38, 62 and 116 atoms. We studied surface charge density and interband-transitions effects on damping and broadening of the surface plasmon resonance absorption spectra. An enhancement in interband-transition energy and a reduction in surface charge density with decrease in the size of clusters are observed. These features result in the damping and broadening of the LSPR absorption spectra. We also study the structural stability and HOMO-LUMO energy gap of copper clusters. The structural stability of nano-clusters reduces by decreasing the size of the clusters. The HOMO-LUMO energy gap is not zero for the clusters with size less than 2 nm which indicates the lack of conduction electrons which are necessary for LSPR absorption. The calculated interband transition energies are in agreement with LSPR absorption data. We also discuss the difference between size dependent LSPR in copper and gold nano-clusters in the experiment based on calculated surface charge density.

  14. Strong dependence of surface plasmon resonance and surface enhanced Raman scattering on the composition of Au-Fe nanoalloys.

    PubMed

    Amendola, Vincenzo; Scaramuzza, Stefano; Agnoli, Stefano; Polizzi, Stefano; Meneghetti, Moreno

    2014-01-01

    Nanoalloys of noble metals with transition metals are crucial components for the integration of plasmonics with magnetic and catalytic properties, as well as for the production of low-cost photonic devices. However, due to synthetic challenges in the realization of nanoscale solid solutions of noble metals and transition metals, very little is known about the composition dependence of plasmonic response in nanoalloys. Here we demonstrate for the first time that the elemental composition of Au-Fe nanoalloys obtained by laser ablation in liquid solution can be tuned by varying the liquid environment. Due to surface passivation and reaction with thiolated ligands, the nanoalloys obtained by our synthetic protocol are structurally and colloidally stable. Hence, we studied the dependence of the surface plasmon resonance (SPR) on the iron fraction and, for the first time, we observed surface enhanced Raman scattering (SERS) in Au-Fe nanoalloys. SPR and SERS performances are strongly affected by the iron content and are investigated using analytical and numerical models. By demonstrating the strong modification of plasmonic properties on the composition, our results provide important insights into the exploitation of Au-Fe nanoalloys in photonics, nanomedicine, magneto-plasmonic and plasmon-enhanced catalysis. Moreover, our findings show that several other plasmonic materials exist beyond gold and silver nanostructures.

  15. Optical/electrical correlations in ZnO. The plasmonic resonance phase diagram

    SciTech Connect

    Look, David C.; Droubay, Timothy C.; Chambers, Scott A.

    2013-08-05

    The Drude equation for dielectric constant ϵ(E) depends on four parameters: ϵ∞, effective mass m*, optical mobility µopt, and optical carrier concentration nopt. By solving this equation at ϵ(Eres)=0, we obtain a relationship between µopt and nopt at constant plasmonic resonance energy Eres [or wavelength λres (µm)=1.2395/Eres (eV)]. A family of µopt versus nopt curves covering a range of λres values (including the limiting wavelength λres=∞) constitutes a plasmonic resonance phase diagram (PRPD) for a semiconductor defined by only ϵ∞ and m*. The PRPD is a convenient instrument that allows an immediate prediction of λres from Hall-effect measurements of µH and nH. We apply the PRPD analysis to a series of ten ZnO samples grown by pulsed laser deposition at 200°C in an ambient of 33%H2:67%Ar and annealed in 25°C steps for 10 min in air at various temperatures from 400 to 600°C. For the samples annealed at 550°C or lower, the µH/nH points yield predicted values of λres that range from 1.07 to 2.80 µm; however, the 575 and 600°C samples are predicted to have no resonance at all. Reflectance curves for the eight samples annealed up to 550 °C decrease slowly from 6 eV down to about Eres= 0.5–1.15 eV, and then increase rapidly for E < Eres. In contrast, there is no such resonance-related increase for the 575 and 600 °C samples. Satisfactory agreement is found between the reflectance minima and the Hall-effect-predicted values of λres.

  16. Optical detection of single non-absorbing molecules using the surface plasmon resonance of a gold nanorod

    NASA Astrophysics Data System (ADS)

    Zijlstra, Peter; Paulo, Pedro M. R.; Orrit, Michel

    2012-06-01

    Existing methods for the optical detection of single molecules require the molecules to absorb light to produce fluorescence or direct absorption signals. This limits the range of species that can be detected, because most molecules are purely refractive. Metal nanoparticles or dielectric resonators can be used to detect non-absorbing molecules because local changes in the refractive index produce a resonance shift. However, current approaches only detect single molecules when the resonance shift is amplified by a highly polarizable label or by a localized precipitation reaction on the surface of a nanoparticle. Without such amplification, single-molecule events can only be identified in a statistical way. Here, we report the plasmonic detection of single molecules in real time without the need for labelling or amplification. Our sensor consists of a single gold nanorod coated with biotin receptors, and the binding of single proteins is detected by monitoring the plasmon resonance of the nanorod with a sensitive photothermal assay. The sensitivity of our device is ~700 times higher than state-of-the-art plasmon sensors and is intrinsically limited by spectral diffusion of the surface plasmon resonance.

  17. Plasmonic Biosensors

    PubMed Central

    Hill, Ryan T.

    2015-01-01

    The unique optical properties of plasmon resonant nanostructures enable exploration of nanoscale environments using relatively simple optical characterization techniques. For this reason, the field of plasmonics continues to garner the attention of the biosensing community. Biosensors based on propagating surface plasmon resonances (SPRs) in films are the most well-recognized plasmonic biosensors, but there is great potential for the new, developing technologies to surpass the robustness and popularity of film-based SPR sensing. This review surveys the current plasmonic biosensor landscape with emphasis on the basic operating principles of each plasmonic sensing technique and the practical considerations when developing a sensing platform with the various techniques. The “gold standard” film SPR technique is reviewed briefly, but special emphasis is devoted to the up-and-coming LSPR-based and plasmonically coupled sensor technology. PMID:25377594

  18. Graphene plasmonics for tuning photon decay rate near metallic split-ring resonator in a multilayered substrate.

    PubMed

    Chen, Yongpin P; Sha, Wei E I; Jiang, Lijun; Hu, Jun

    2015-02-09

    Study of photon decay rate is essential to various optical devices, where graphene is an emerging building block due to its electrical tunability. In this paper, we study photon decay rate of a quantum emitter near a metallic split-ring resonator, which is embedded in a multilayered substrate incorporating a graphene layer. Analyzing photon decay rate in such a complex multilayered system is not only computationally challenging but also highly important to experimentally realizable devices. First, the dispersion relation of graphene plasmonics supported at a dieletric/graphene/dielectric structure is investigated systematically. Meanwhile, the dispersion relation of metallic plasmonics supported at a dielectric/metal structure is studied comparatively. According to our investigation, graphene offers several flexible tuning routes for manipulating photon decay rate, including tunable chemical potential and the emitter's position and polarization. Next, considering plasmonic waves in a graphene sheet occur in the infrared regime, we carefully design a metallic split ring resonating around the same frequency range. Consequently, this design enables a mutual interaction between graphene plasmonics and metallic plasmonics. The boundary element method with a multilayered medium Green's function is adopted in the numerical simulation. Blue-shifted and splitting resonance peaks are theoretically observed, which suggests a strong mode coupling. Moreover, the mode coupling has a switch on-off feature via electrostatically doping the graphene sheet. This work is helpful to dynamically manipulate photon decay rate in complex optical devices.

  19. Surface plasmon resonator using high sensitive resonance telecommunication wavelengths for DNA sensors of Mycobacterium tuberculosis with thiol-modified probes.

    PubMed

    Hsu, Shih-Hsiang; Hung, Shao-Chiang; Chen, Yu-Kun; Jian, Zhi-Hao

    2014-12-25

    Various analytes can be verified by surface plasmon resonance, thus continuous improvement of this sensing technology is crucial for better sensing selection and higher sensitivity. The SPR sensitivity on the wavelength modulation is enhanced with increasing wavelengths. The telecommunication wavelength range was then utilized to detect Mycobacterium tuberculosis (MTB) deoxyribonucleic acid (DNA) under two situations, without immobilization and with 5'-thiol end labeled IS6100 DNA probes, for SPR sensitivity comparison. The experimental data demonstrated that the SPR sensitivity increased more than 13 times with the wavelength modulation after immobilization. Since the operating wavelength accuracy of a tunable laser source can be controlled within 0.001 nm, the sensitivity and resolution on immobilized MTB DNA were determined as 1.04 nm/(μg/mL) and 0.9 ng/mL, respectively.

  20. Detection of DNA hybridisation in a diluted serum matrix by surface plasmon resonance and film bulk acoustic resonators.

    PubMed

    Auer, Sanna; Nirschl, Martin; Schreiter, Matthias; Vikholm-Lundin, Inger

    2011-05-01

    Nanomolar quantities of single-stranded DNA products ~100 nucleotides long can be detected in diluted 1% serum by surface plasmon resonance (SPR) and film bulk acoustic resonators (FBARs). We have used a novel FBAR sensor in parallel with SPR and obtained promising results with both the acoustic and the optical device. Oligonucleotides and a repellent lipoamide, Lipa-DEA, were allowed to assemble on the sensor chip surfaces for only 15 min by dispensing. Lipa-DEA surrounds the analyte-binding probes on the surface and effectively reduces the non-specific binding of bovine serum albumin and non-complementary strands. In a highly diluted serum matrix, the non-specific binding is, however, a hindrance, and the background response must be reduced. Nanomolar concentrations of short complementary oligos could be detected in buffer, whereas the response was too low to be measured in serum. DNA strands that are approximately 100 base pairs long at concentrations as low as 1-nM could be detected both in buffer and in 1% serum by both SPR and the FBAR resonator.