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Sample records for sensitive nanoprobes binary

  1. A novel nanoprobe for the sensitive detection of Francisella tularensis.

    PubMed

    Kim, Ji-eun; Seo, Youngmin; Jeong, Yoon; Hwang, Mintai P; Hwang, Jangsun; Choo, Jaebum; Hong, Jong Wook; Jeon, Jun Ho; Rhie, Gi-eun; Choi, Jonghoon

    2015-11-15

    Francisella tularensis is a human zoonotic pathogen and the causative agent of tularemia, a severe infectious disease. Given the extreme infectivity of F. tularensis and its potential to be used as a biological warfare agent, a fast and sensitive detection method is highly desirable. Herein, we construct a novel detection platform composed of two units: (1) Magnetic beads conjugated with multiple capturing antibodies against F. tularensis for its simple and rapid separation and (2) Genetically-engineered apoferritin protein constructs conjugated with multiple quantum dots and a detection antibody against F. tularensis for the amplification of signal. We demonstrate a 10-fold increase in the sensitivity relative to traditional lateral flow devices that utilize enzyme-based detection methods. We ultimately envision the use of our novel nanoprobe detection platform in future applications that require the highly-sensitive on-site detection of high-risk pathogens. PMID:26057442

  2. A highly sensitive and flexible magnetic nanoprobe labeled immunochromatographic assay platform for pathogen Vibrio parahaemolyticus.

    PubMed

    Liu, Yingying; Zhang, Zhaohuan; Wang, Yilong; Zhao, Yong; Lu, Ying; Xu, Xiaowei; Yan, Jun; Pan, Yingjie

    2015-10-15

    A magnetic nanoprobe labeled immunochromatographic test strip (MNP/ICTS) was developed to detect food-borne pathogen Vibrio parahaemolyticus. Specific antibody against V. parahaemolyticus was used as test line by coating onto the nitrocellulose membrane. Magnetic nanoprobe was prepared by immobilizing the specific antibody onto the surface of superparamagnetic nanoparticles. Specificity and sensitivity of the MNP/ICTS system were verified by artificially contaminated shrimp homogenate samples. Reliability and application feasibility of the MNP/ICTS system were demonstrated by using seafood samples (n=36). Comparing with polymerase chain reaction (PCR) and traditional culture methods, the MNP/ICTS system is found to be not only a rapid qualitative analysis (~10 min), but also an accurately quantitative detection platform. Through its rapid magnetic separation property, the MNP/ICTS system is capable to flexibly combine with a sample enrichment and pre-incubation process. This combination makes the qualitative sensitivity for the food samples surged more than 100-fold. A naked-eye observation of 1.58×10(2) CFU/g V. parahaemolyticus was realized. This sensitivity could meet the V. parahaemolyticus test threshold value in many countries. Also, the total sample pre-treatment plus MNP/ICTS assay only needs about 4.5h. Namely, we can get test results in a day. Hence, the developed MNP/ICTS assay platform is simple, rapid and highly sensitive. It is a flexible test platform for pathogen detection. The favorable comparison with PCR and culture methods further proves that the developed MNP/ICTS is applicable into food-borne pathogen or other areas where a simple, rapid, sensitive and point-of-care analysis is desirable. PMID:26188497

  3. Photon upconversion sensitized nanoprobes for sensing and imaging of pH

    NASA Astrophysics Data System (ADS)

    Arppe, Riikka; Näreoja, Tuomas; Nylund, Sami; Mattsson, Leena; Koho, Sami; Rosenholm, Jessica M.; Soukka, Tero; Schäferling, Michael

    2014-05-01

    Acidic pH inside cells indicates cellular dysfunctions such as cancer. Therefore, the development of optical pH sensors for measuring and imaging intracellular pH is a demanding challenge. The available pH-sensitive probes are vulnerable to e.g. photobleaching or autofluorescence background in biological materials. Our approach circumvents these problems due to near infrared excitation and upconversion photoluminescence. We introduce a nanosensor based on upconversion resonance energy transfer (UC-RET) between an upconverting nanoparticle (UCNP) and a fluorogenic pH-dependent dye pHrodo™ Red that was covalently bound to the aminosilane surface of the nanoparticles. The sensitized fluorescence of the pHrodo™ Red dye increases strongly with decreasing pH. By referencing the pH-dependent emission of pHrodo™ Red with the pH-insensitive upconversion photoluminescence of the UCNP, we developed a pH-sensor which exhibits a dynamic range from pH 7.2 to 2.5. The applicability of the introduced pH nanosensor for pH imaging was demonstrated by imaging the two emission wavelengths of the nanoprobe in living HeLa cells with a confocal fluorescence microscope upon 980 nm excitation. This demonstrates that the presented pH-nanoprobe can be used as an intracellular pH-sensor due to the unique features of UCNPs: excitation with deeply penetrating near-infrared light, high photostability, lack of autofluorescence and biocompatibility due to an aminosilane coating.Acidic pH inside cells indicates cellular dysfunctions such as cancer. Therefore, the development of optical pH sensors for measuring and imaging intracellular pH is a demanding challenge. The available pH-sensitive probes are vulnerable to e.g. photobleaching or autofluorescence background in biological materials. Our approach circumvents these problems due to near infrared excitation and upconversion photoluminescence. We introduce a nanosensor based on upconversion resonance energy transfer (UC-RET) between an

  4. Reaction-Driven Self-Assembled Micellar Nanoprobes for Ratiometric Fluorescence Detection of CS2 with High Selectivity and Sensitivity.

    PubMed

    Lu, Wei; Xiao, Peng; Liu, Zhenzhong; Gu, Jincui; Zhang, Jiawei; Huang, Youju; Huang, Qing; Chen, Tao

    2016-08-10

    The detection of highly toxic CS2, which is known as a notorious occupational hazard in various industrial processes, is important from both environmental and public safety perspectives. We describe here a robust type of chemical-reaction-based supramolecular fluorescent nanoprobes for ratiometric determination of CS2 with high selectivity and sensitivity in water medium. The micellar nanoprobes self-assemble from amphiphilic pyrene-modified hyperbranched polyethylenimine (Py-HPEI) polymers with intense pyrene excimer emission. Selective sensing is based on a CS2-specific reaction with hydrophilic amino groups to produce hydrophobic dithiocarbamate moieties, which can strongly quench the pyrene excimer emission via a known photoinduced electron transfer (PET) mechanism. Therefore, the developed micellar nanoprobes are free of the H2S interference problem often encountered in the widely used colorimetric assays and proved to show high selectivity over many potentially competing chemical species. Importantly, the developed approach is capable of CS2 sensing even in complex tap and river water samples. In addition, in view of the modular design principle of these powerful micellar nanoprobes, the sensing strategy used here is expected to be applicable to the development of various sensory systems for other environmentally important guest species. PMID:27419849

  5. Highly selective and sensitive nanoprobes for cyanide based on gold nanoclusters with red fluorescence emission

    NASA Astrophysics Data System (ADS)

    Zhang, Guomei; Qiao, Yunyun; Xu, Ting; Zhang, Caihong; Zhang, Yan; Shi, Lihong; Shuang, Shaomin; Dong, Chuan

    2015-07-01

    We report a novel and environmentally friendly fluorescent probe for detecting the cyanide ion (CN-) using l-amino acid oxidase (LAAOx)-protected Au nanoclusters (LAAOx@AuNCs) with red emission. The fluorescence-based sensing behaviour of LAAOx@AuNCs towards anions was investigated in buffered aqueous media. Among the anions studied, CN- was found to effectively quench the fluorescence emission of AuNCs based on CN- induced Au core decomposition. Excellent sensitivity and selectivity toward the detection of CN- in aqueous solution were observed. The CN- detection limit was determined to be approximately 180 nM, which is 15 times lower than the maximum level (2700 nM) of CN- in drinking water permitted by the World Health Organization (WHO). A linear relationship between the fluorescence intensity and CN- concentration was observed in two ranges of CN- concentration, including 3.2 × 10-6 to 3.4 × 10-5 mol L-1 and 3.81 × 10-5 to 1.04 × 10-4 mol L-1. The high sensitivity and selectivity to CN- among the 17 types of anions make the AuNCs good candidates for use in fluorescent nanoprobes of CN-.

  6. FRET-based biofriendly apo-GO(x)-modified gold nanoprobe for specific and sensitive glucose sensing and cellular imaging.

    PubMed

    Li, Lu; Gao, Feifei; Ye, Jian; Chen, Zhenzhen; Li, Qingling; Gao, Wen; Ji, Lifei; Zhang, Ruirui; Tang, Bo

    2013-10-15

    In this paper, we have developed a biofriendly and high sensitive apo-GOx (inactive form of glucose oxidase)-modified gold nanoprobe for quantitative analysis of glucose and imaging of glucose consumption in living cells. This detection system is based on fluorescence resonance energy transfer between apo-GOx modified AuNPs (Au nanoparticles) and dextran-FITC (dextran labeled with fluorescein isothiocyanate). Once glucose is present, quenched fluorescence of FITC recovers due to the higher affinity of apo-GOx for glucose over dextran. The nanoprobe shows excellent selectivity toward glucose over other monosaccharides and most biological species present in living cells. A detection limit as low as 5 nM demonstrates the high sensitivity of the nanoprobe. Introduction of apo-GOx, instead of GOx, can avoid the consumption of O2 and production of H2O2 during the interaction with glucose, which may exert effects on normal physiological events in living cells and even lead to cellular damage. Due to the low toxicity of this detection system and reliable cellular uptake ability of AuNPs, imaging of intracellular glucose consumption was successfully realized in cancer cells. PMID:24032474

  7. Dual-emitting quantum dot/carbon nanodot-based nanoprobe for selective and sensitive detection of Fe(3+) in cells.

    PubMed

    Wang, Chuanxi; Huang, Yijun; Jiang, Kaili; Humphrey, Mark G; Zhang, Chi

    2016-07-21

    A novel dual-emitting fluorescence probe is developed for rapid and ultrasensitive detection of Fe(3+). The nanoprobe is prepared by coating CdSe semiconductor quantum dots (SQDs) onto the surface of carbon nanodot (CND) doped TiO2 microspheres. The as-prepared nanoprobe exhibits the corresponding dual emissions at 436 and 596 nm for CNDs and CdSe, respectively, under a single excitation wavelength. The blue fluorescence of the CNDs is insensitive to Fe(3+), whereas the orange emission of the CdSe SQDs is functionalized to be selectively quenched by Fe(3+). The intensity ratio of I436/I596 shows a good linear relationship with the concentration of Fe(3+) in the range of 10(-9) to 10(-5) M. The nanoprobe provides an effective platform for the reliable detection of Fe(3+) with a detection limit as low as 10 nM. Besides, this ratiometric nanosensor exhibits good selectivity for Fe(3+) over other metal ions. The results reveal that the nanoprobe could provide a sensitive sensor for rapid detection of Fe(3+) with high selectivity and sensitivity. Moreover, 293T cells are used as models to achieve a potential application as a probe for monitoring Fe(3+) in cells. Thus, these dual-emitting nanoprobes could work as an alternative to conventional fluorescence probes for biolabeling, sensing and other applications. PMID:27197565

  8. Monodispersity of magnetic immuno-nanoprobes enhances the detection sensitivity of low abundance biomarkers in one drop of serum.

    PubMed

    Capangpangan, Rey Y; dela Rosa, Mira Anne C; Obena, Rofeamor P; Chou, Yu-Jen; Tzou, Der-Lii; Shih, Shao-Ju; Chiang, Ming-Hsi; Lin, Chun-Cheng; Chen, Yu-Ju

    2015-11-21

    To enhance the detection sensitivity of target clinical protein biomarkers, a simple and rapid nanoprobe-based immuno-affinity mass spectrometry assay employing biocompatible monodisperse magnetic nanoparticles (MNPs) is reported herein. The MNPs were synthesized via a streamlined protocol that includes (a) fabrication of core MNPs using the thermal decomposition method to minimize aggregation, (b) surface protection by gold coating (MNP@Au) and surfactant coating using MNP@IGEPAL to improve hydrophilicity, and lastly, (c) oriented functionalization of antibodies to maximize immuno-affinity. The enrichment performances of the monodisperse MNPs for the C-reactive protein (CRP) serum biomarker were then evaluated and compared with aggregated magnetic nanoparticles synthesized from the conventional co-precipitation method (MNP(CP)). The detection sensitivity for CRP at an extremely low amount of serum sample (1 μL) was enhanced ∼19- and ∼15-fold when monodisperse MNP@Au and MNP@IGEPAL, respectively, were used. Furthermore, the detection sensitivity of CRP by this approach (1 ng mL(-1), S/N = 3) provided a 1000-fold sensitivity enhancement to the clinical cut-off (1 μg mL(-1)) of CRP. We supposed that these observed improvements are due to the enhanced nanoparticle dispersibility and size uniformity which eliminated completely other non-specific binding of high-abundance serum proteins. Most interestingly, the enrichment efficiency correlates more closely with the MNP dispersibility than the ligand density. Our investigation revealed the critical role of MNP dispersibility, as well as provided mechanistic insight into its impact on immunoaffinity enrichment and detection of CRP in one drop of serum sample. This strategy offers an essential advantage over the other methods by providing a simple and facile biofunctionalization protocol while maintaining excellent solvent dispersibility of MNPs. PMID:26447802

  9. A cobalt oxyhydroxide nanoflake-based nanoprobe for the sensitive fluorescence detection of T4 polynucleotide kinase activity and inhibition.

    PubMed

    Cen, Yao; Yang, Yuan; Yu, Ru-Qin; Chen, Ting-Ting; Chu, Xia

    2016-04-14

    Phosphorylation of nucleic acids with 5'-OH termini catalyzed by polynucleotide kinase (PNK) is an inevitable process and has been implicated in many important cellular events. Here, we found for the first time that there was a significant difference in the adsorbent ability of cobalt oxyhydroxide (CoOOH) nanoflakes between single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA), which resulted in the fluorescent dye-labeled dsDNA still retaining strong fluorescence emission, while the fluorescence signal of ssDNA was significantly quenched by CoOOH nanoflakes. Based on this discovery, we developed a CoOOH nanoflake-based nanoprobe for the fluorescence sensing of T4 PNK activity and its inhibition by combining it with λ exonuclease cleavage reaction. In the presence of T4 PNK, dye-labeled dsDNA was phosphorylated and then cleaved by λ exonuclease to generate ssDNA, which could adsorb on the CoOOH nanoflakes and whose fluorescence was quenched by CoOOH nanoflakes. Due to the high quenching property of CoOOH nanoflakes as an efficient energy acceptor, a sensitive and selective sensing approach with satisfactory performance for T4 PNK sensing in a complex biological matrix has been successfully constructed and applied to the screening of inhibitors. The developed approach may potentially provide a new platform for further research, clinical diagnosis, and drug discovery of nucleotide kinase related diseases. PMID:27030367

  10. A cobalt oxyhydroxide nanoflake-based nanoprobe for the sensitive fluorescence detection of T4 polynucleotide kinase activity and inhibition

    NASA Astrophysics Data System (ADS)

    Cen, Yao; Yang, Yuan; Yu, Ru-Qin; Chen, Ting-Ting; Chu, Xia

    2016-04-01

    Phosphorylation of nucleic acids with 5'-OH termini catalyzed by polynucleotide kinase (PNK) is an inevitable process and has been implicated in many important cellular events. Here, we found for the first time that there was a significant difference in the adsorbent ability of cobalt oxyhydroxide (CoOOH) nanoflakes between single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA), which resulted in the fluorescent dye-labeled dsDNA still retaining strong fluorescence emission, while the fluorescence signal of ssDNA was significantly quenched by CoOOH nanoflakes. Based on this discovery, we developed a CoOOH nanoflake-based nanoprobe for the fluorescence sensing of T4 PNK activity and its inhibition by combining it with λ exonuclease cleavage reaction. In the presence of T4 PNK, dye-labeled dsDNA was phosphorylated and then cleaved by λ exonuclease to generate ssDNA, which could adsorb on the CoOOH nanoflakes and whose fluorescence was quenched by CoOOH nanoflakes. Due to the high quenching property of CoOOH nanoflakes as an efficient energy acceptor, a sensitive and selective sensing approach with satisfactory performance for T4 PNK sensing in a complex biological matrix has been successfully constructed and applied to the screening of inhibitors. The developed approach may potentially provide a new platform for further research, clinical diagnosis, and drug discovery of nucleotide kinase related diseases.Phosphorylation of nucleic acids with 5'-OH termini catalyzed by polynucleotide kinase (PNK) is an inevitable process and has been implicated in many important cellular events. Here, we found for the first time that there was a significant difference in the adsorbent ability of cobalt oxyhydroxide (CoOOH) nanoflakes between single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA), which resulted in the fluorescent dye-labeled dsDNA still retaining strong fluorescence emission, while the fluorescence signal of ssDNA was significantly quenched by Co

  11. Förster Resonance Energy Transfer-Based Self-Assembled Nanoprobe for Rapid and Sensitive Detection of Postoperative Pancreatic Fistula.

    PubMed

    Hamano, Nobuhito; Murata, Masaharu; Kawano, Takahito; Piao, Jing Shu; Narahara, Sayoko; Nakata, Ryosuke; Akahoshi, Tomohiko; Ikeda, Tetsuo; Hashizume, Makoto

    2016-03-01

    Postoperative pancreatic fistula (POPF) is the most serious and challenging complication following gastroenterological surgery. Activated pancreatic juice leaking from the organ remnant contains proteases that attack the surrounding tissue, potentially leading to severe inflammation, tissue necrosis, and fistula formation. However, it is difficult to observe pancreatic leakage during surgery and to evaluate the protease activity of leaked fluid at the patient's bedside. This report describes a protein nanocage-based protease ratiometric sensor comprising a pancreatic protease-sensitive small heat-shock protein (HSP) 16.5, which is a naturally occurring protein in Methanococcus jannaschii that forms a spherical structure by self-assembly of 24 subunits, and a chemically conjugated donor-acceptor dye pair for Förster resonance energy transfer (FRET). The HSP-FRET probe was constructed by subunit exchange of each dye-labeled engineered HSP, resulting in a spherical nanocage of approximately 10 nm in diameter, which exhibited very high stability against degradation in blood plasma and no remarkable toxicity in mice. The efficiency of FRET was found to depend on both the dye orientation and the acceptor/donor ratio. Pancreatic proteases, including trypsin, α-chymotrypsin, and elastase, were quantitatively analyzed by fluorescence recovery with high specificity using the HSP-FRET nanoprobe. Furthermore, the HSP-FRET nanoprobe was sufficiently sensitive to detect POPF in the pancreatic juice of patients using only the naked eye within 10 min. Thus, this novel nanoprobe is proposed as an effective and convenient tool for the detection of POPF and the visualization of activated pancreatic juice during gastroenterological surgery. PMID:26845508

  12. Gold nanoprobes-based resonance Rayleigh scattering assay platform: Sensitive cytosensing of breast cancer cells and facile monitoring of folate receptor expression.

    PubMed

    Cai, Huai-Hong; Pi, Jiang; Lin, Xiaoying; Li, Baole; Li, Aiqun; Yang, Pei-Hui; Cai, Jiye

    2015-12-15

    A rapid, facile assay for sensitive cytosensing of breast cancer cells should help to guide potential medical evaluation for breast cancer. Here, we report development of novel resonance Rayleigh scattering (RRS) cytosensor for cell recognitions and folate (FA) receptor expression analyses on living cells. Using FA-conjugated gold nanoparticles (FA-AuNPs) as nanoprobes, the constructed nanoprobes-assembled recognition interface could increase the binding capacity for cell recognition, amplify Au-aggregates-enhanced RRS signal, and then enhance the sensitivity for membrane antibody assay. FA-AuNPs-based RRS measurements enabled a distinct 34-times-enhancement in RRS intensities after incubation with human breast cancer cells, compared with normal cells. Receptor-targeted cytosensor was used to quantitatively detect human breast cancer MCF-7, liver cancer HepG2 and normal cells, which expressing different amount of FA receptor, respectively. The detection limit for MCF-7 cells was 12 cells/mL with good selectivity and reproducibility. Furthermore, the proposed cytosensor allowed for dynamic evaluation of FA receptor expression on different living cells after dihydroartemisinin stimulus. This assay platform shows the good potential for clinical diagnostics and antibody-targeted drug screening. PMID:26141102

  13. Chemiluminescence immunoassay for the rapid and sensitive detection of antibody against porcine parvovirus by using horseradish peroxidase/detection antibody-coated gold nanoparticles as nanoprobes.

    PubMed

    Zhou, Yuan; Zhou, Tao; Zhou, Rui; Hu, Yonggang

    2014-06-01

    A rapid, simple, facile, sensitive and enzyme-amplified chemiluminescence immunoassay (CLIA) method to detect antibodies against porcine parvovirus has been developed. Horseradish peroxidase (HRP) and the detection antibody were simultaneously co-immobilized on the surface of gold nanoparticles using the electrostatic method to form gold nanoparticle-based nanoprobes. This nanoprobe was employed in a sandwich-type CLIA, which enables CL signal readout from enzymatic catalysis and results in signal amplification. The presence of porcine parvovirus infection was determined in porcine parvovirus antibodies by measuring the CL intensity caused by the reaction of HRP-luminol with H2 O2 . Under optimal conditions, the obtained calibration plot for the standard positive serum was approximately linear within the dilution range of 1:80 to 1:5120. The limit of detection for the assay was 1:10,240 (S/N = 3), which is much lower than that typically achieved with an enzyme-linked immunosorbent assay (1:160; S/N = 3). A series of repeatability measurements using 1:320-fold diluted standard positive serum gave reproducible results with a relative standard deviation of 4.9% (n = 11). The ability of the immunosensor to analyze clinical samples was tested on porcine sera. The immunosensor had an efficiency of 90%, a sensitivity of 93.3%, and a specificity of 87.5% relative to the enzyme-linked immunosorbent assay results. PMID:23832716

  14. Shape-changing magnetic assemblies as high-sensitivity NMR-readable nanoprobes

    NASA Astrophysics Data System (ADS)

    Zabow, G.; Dodd, S. J.; Koretsky, A. P.

    2015-04-01

    Fluorescent and plasmonic labels and sensors have revolutionized molecular biology, helping visualize cellular and biomolecular processes. Increasingly, such probes are now being designed to respond to wavelengths in the near-infrared region, where reduced tissue autofluorescence and photon attenuation enable subsurface in vivo sensing. But even in the near-infrared region, optical resolution and sensitivity decrease rapidly with increasing depth. Here we present a sensor design that obviates the need for optical addressability by operating in the nuclear magnetic resonance (NMR) radio-frequency spectrum, where signal attenuation and distortion by tissue and biological media are negligible, where background interferences vanish, and where sensors can be spatially located using standard magnetic resonance imaging (MRI) equipment. The radio-frequency-addressable sensor assemblies presented here comprise pairs of magnetic disks spaced by swellable hydrogel material; they reversibly reconfigure in rapid response to chosen stimuli, to give geometry-dependent, dynamic NMR spectral signatures. The sensors can be made from biocompatible materials, are themselves detectable down to low concentrations, and offer potential responsive NMR spectral shifts that are close to a million times greater than those of traditional magnetic resonance spectroscopies. Inherent adaptability should allow such shape-changing systems to measure numerous different environmental and physiological indicators, thus providing broadly generalizable, MRI-compatible, radio-frequency analogues to optically based probes for use in basic chemical, biological, medical and engineering research.

  15. Shape-changing magnetic assemblies as high-sensitivity NMR-readable nanoprobes

    PubMed Central

    Zabow, G.; Dodd, S. J.; Koretsky, A. P.

    2015-01-01

    Fluorescent and plasmonic labels and sensors have revolutionized molecular biology, helping visualize in vitro cellular and biomolecular processes1–3. Increasingly, such probes are now designed to respond to wavelengths in the near infrared region, where reduced tissue autofluorescence and photon attenuation enable subsurface in vivo sensing4. But even in the near infrared, optical resolution and sensitivity decrease rapidly with increasing depth. Here we present a sensor design that obviates the need for optical addressability by operating in the NMR radio-frequency (RF) spectrum, where signal attenuation and distortion by tissue and biological media are negligible, where background interferences vanish, and where sensors can be spatially located using standard magnetic resonance imaging (MRI) equipment. The RF-addressable sensor assemblies presented here are comprised of pairs of magnetic disks spaced by swellable hydrogel material; they reversibly reconfigure in rapid response to chosen stimuli, to give geometry-dependent, dynamic NMR spectral signatures. Sensors can be made from biocompatible materials, are detectable down to low concentrations, and offer potential responsive NMR spectral shifts approaching a million times those of traditional magnetic resonance spectroscopies. Inherent adaptability should allow such shape-changing systems to measure numerous different environmental and physiological indicators, affording broadly generalizable, MRI-compatible, RF analogues to optically-based probes for use in basic chemical, biological and medical research. PMID:25778701

  16. Shape-changing magnetic assemblies as high-sensitivity NMR-readable nanoprobes.

    PubMed

    Zabow, G; Dodd, S J; Koretsky, A P

    2015-04-01

    Fluorescent and plasmonic labels and sensors have revolutionized molecular biology, helping visualize cellular and biomolecular processes. Increasingly, such probes are now being designed to respond to wavelengths in the near-infrared region, where reduced tissue autofluorescence and photon attenuation enable subsurface in vivo sensing. But even in the near-infrared region, optical resolution and sensitivity decrease rapidly with increasing depth. Here we present a sensor design that obviates the need for optical addressability by operating in the nuclear magnetic resonance (NMR) radio-frequency spectrum, where signal attenuation and distortion by tissue and biological media are negligible, where background interferences vanish, and where sensors can be spatially located using standard magnetic resonance imaging (MRI) equipment. The radio-frequency-addressable sensor assemblies presented here comprise pairs of magnetic disks spaced by swellable hydrogel material; they reversibly reconfigure in rapid response to chosen stimuli, to give geometry-dependent, dynamic NMR spectral signatures. The sensors can be made from biocompatible materials, are themselves detectable down to low concentrations, and offer potential responsive NMR spectral shifts that are close to a million times greater than those of traditional magnetic resonance spectroscopies. Inherent adaptability should allow such shape-changing systems to measure numerous different environmental and physiological indicators, thus providing broadly generalizable, MRI-compatible, radio-frequency analogues to optically based probes for use in basic chemical, biological, medical and engineering research. PMID:25778701

  17. SHG nanoprobes: advancing harmonic imaging in biology.

    PubMed

    Dempsey, William P; Fraser, Scott E; Pantazis, Periklis

    2012-05-01

    Second harmonic generating (SHG) nanoprobes have recently emerged as versatile and durable labels suitable for in vivo imaging, circumventing many of the inherent drawbacks encountered with classical fluorescent probes. Since their nanocrystalline structure lacks a central point of symmetry, they are capable of generating second harmonic signal under intense illumination - converting two photons into one photon of half the incident wavelength - and can be detected by conventional two-photon microscopy. Because the optical signal of SHG nanoprobes is based on scattering, rather than absorption as in the case of fluorescent probes, they neither bleach nor blink, and the signal does not saturate with increasing illumination intensity. When SHG nanoprobes are used to image live tissue, the SHG signal can be detected with little background signal, and they are physiologically inert, showing excellent long-term photostability. Because of their photophysical properties, SHG nanoprobes provide unique advantages for molecular imaging of living cells and tissues with unmatched sensitivity and temporal resolution. PMID:22392481

  18. Gold nanoprobes for theranostics

    PubMed Central

    Panchapakesan, Balaji; Book-Newell, Brittany; Sethu, Palaniappan; Rao, Madhusudhana; Irudayaraj, Joseph

    2011-01-01

    Gold nanoprobes have become attractive diagnostic and therapeutic agents in medicine and life sciences research owing to their reproducible synthesis with atomic level precision, unique physical and chemical properties, versatility of their morphologies, flexibility in functionalization, ease of targeting, efficiency in drug delivery and opportunities for multimodal therapy. This review highlights some of the recent advances and the potential for gold nanoprobes in theranostics. PMID:22122586

  19. Plasmonic nanoprobes for SERS biosensing and bioimaging

    PubMed Central

    Vo-Dinh, Tuan; Wang, Hsin-Neng; Scaffidi, Jonathan

    2013-01-01

    This article provides an overview of the development and application of plasmonic nanoprobes developed in our laboratory for biosensing and bioimaging. We describe the use of plasmonics surface-enhanced Raman scattering (SERS) gene probes for the detection of diseases using DNA hybridization to target biospecies (HIV gene, breast cancer genes etc.). For molecular imaging, we describe a hyperspectral surface-enhanced Raman imaging (HSERI) system that combines imaging capabilities with SERS detection to identify cellular components using Raman dye-labeled silver nanoparticles in cellular systems The detection of specific target DNA sequences associated with breast cancer using “molecular sentinel” nanoprobes and the use of a plasmonic nanosensor to monitor pH in single cells are presented and discussed. Plasmonic nanosensors and nanoprobes have been developed as sensitive and selective tolls for environmental monitoring, cellular biosensing, medical diagnostics and high throughput screnning. PMID:19517422

  20. Gold nanoprobe functionalized with specific fusion protein selection from phage display and its application in rapid, selective and sensitive colorimetric biosensing of Staphylococcus aureus.

    PubMed

    Liu, Pei; Han, Lei; Wang, Fei; Petrenko, Valery A; Liu, Aihua

    2016-08-15

    Staphylococcus aureus (S. aureus) is one of the most ubiquitous pathogens in public healthcare worldwide. It holds great insterest in establishing robust analytical method for S. aureus. Herein, we report a S. aureus-specific recognition element, isolated from phage monoclone GQTTLTTS, which was selected from f8/8 landscape phage library against S. aureus in a high-throughput way. By functionalizing cysteamine (CS)-stabilized gold nanoparticles (CS-AuNPs) with S. aureus-specific pVIII fusion protein (fusion-pVIII), a bifunctional nanoprobe (CS-AuNPs@fusion-pVIII) for S. aureus was developed. In this strategy, the CS-AuNPs@fusion-pVIII could be induced to aggregate quickly in the presence of target S. aureus, resulting in a rapid colorimetric response of gold nanoparticles. More importantly, the as-designed probe exhibited excellent selectivity over other bacteria. Thus, the CS-AuNPs@fusion-pVIII could be used as the indicator of target S. aureus. This assay can detect as low as 19CFUmL(-1)S. aureus within 30min. Further, this approach can be applicable to detect S. aureus in real water samples. Due to its sensitivity, specificity and rapidness, this proposed method is promising for on-site testing of S. aureus without using any costly instruments. PMID:27085951

  1. Magnetomotive Molecular Nanoprobes

    PubMed Central

    John, Renu; Boppart, Stephen A.

    2012-01-01

    Tremendous developments in the field of biomedical imaging in the past two decades have resulted in the transformation of anatomical imaging to molecular-specific imaging. The main approaches towards imaging at a molecular level are the development of high resolution imaging modalities with high penetration depths and increased sensitivity, and the development of molecular probes with high specificity. The development of novel molecular contrast agents and their success in molecular optical imaging modalities have lead to the emergence of molecular optical imaging as a more versatile and capable technique for providing morphological, spatial, and functional information at the molecular level with high sensitivity and precision, compared to other imaging modalities. In this review, we discuss a new class of dynamic contrast agents called magnetomotive molecular nanoprobes for molecular-specific imaging. Magnetomotive agents are superparamagnetic nanoparticles, typically iron-oxide, that are physically displaced by the application of a small modulating external magnetic field. Dynamic phase-sensitive position measurements are performed using any high resolution imaging modality, including optical coherence tomography (OCT), ultrasonography, or magnetic resonance imaging (MRI). The dynamics of the magnetomotive agents can be used to extract the biomechanical tissue properties in which the nanoparticles are bound, and the agents can be used to deliver therapy via magnetomotive displacements to modulate or disrupt cell function, or hyperthermia to kill cells. These agents can be targeted via conjugation to antibodies, and in vivo targeted imaging has been shown in a carcinogen-induced rat mammary tumor model. The iron-oxide nanoparticles also exhibit negative T2 contrast in MRI, and modulations can produce ultrasound imaging contrast for multimodal imaging applications. PMID:21517766

  2. Nanoprobes with optical tweezers for biological applications

    NASA Astrophysics Data System (ADS)

    Kendrick, Mark; McIntyre, David; Ostroverkhova, Oksana; Bychkova, Valeriya; Shvarev, Alexey

    2010-03-01

    We explore the use of sub-micron sized particles in optical tweezer traps as nanoprobes in microfluidic devices and biological cells. For applications that require high spatial resolution, the ability to suppress the particle's natural Brownian motion down to the nanometer or sub-nanometer scales is essential. However, the optical tweezer force scales with the volume of the particle making it difficult to confine and manipulate nanometer sized particles with high precision. To overcome this difficulty, we explore the possibility of using optically resonant particles as nanoprobes. The resonant particles should experience an increase in the optical tweezer force at wavelengths on the red side of the absorption resonance, resulting in a tighter confinement. We explore this phenomenon by measuring the trapping force acting on resonant particles (dye-filled polymeric and metallic particles) as a function of trapping laser wavelength and discuss the feasibility of using them as a high spatial resolution probe. In addition, we use similar particles as optically trapped nanoprobes to monitor temporal and spatial differences in an inhomogeneous environment; for example, we have developed pH-sensitive fluorescent nanoprobes for biological applications.

  3. Plasmonic nanoprobes: from chemical sensing to medical diagnostics and therapy

    NASA Astrophysics Data System (ADS)

    Vo-Dinh, Tuan; Fales, Andrew M.; Griffin, Guy D.; Khoury, Christopher G.; Liu, Yang; Ngo, Hoan; Norton, Stephen J.; Register, Janna K.; Wang, Hsin-Neng; Yuan, Hsiangkuo

    2013-10-01

    This article provides an overview of the development and applications of plasmonics-active nanoprobes in our laboratory for chemical sensing, medical diagnostics and therapy. Molecular Sentinel nanoprobes provide a unique tool for DNA/RNA biomarker detection both in a homogeneous solution or on a chip platform for medical diagnostics. The possibility of combining spectral selectivity and high sensitivity of the surface-enhanced Raman scattering (SERS) process with the inherent molecular specificity of nanoprobes provides an important multiplex diagnostic modality. Gold nanostars can provide an excellent multi-modality platform, combining two-photon luminescence with photothermal therapy as well as Raman imaging with photodynamic therapy. Several examples of optical detection using SERS and photonics-based treatments are presented to illustrate the usefulness and potential of the plasmonic nanoprobes for theranostics, which seamlessly combines diagnostics and therapy.

  4. An upconversion luminescence nanoprobe for the ultrasensitive detection of hyaluronidase.

    PubMed

    Wang, Zhe; Li, Xiaohua; Song, Yanchao; Li, Lihong; Shi, Wen; Ma, Huimin

    2015-06-01

    A new upconversion luminescence nanoprobe for the detection of hyaluronidase has been developed by coupling the hyaluronic acid-bearing upconversion fluorescence nanoparticles (HA-UCNPs) with poly(m-phenylenediamine) (PMPD) nanospheres via covalent linkage. The nanoprobe alone exhibits an extremely low background signal owing to the effective fluorescence quenching by electron-rich PMPD and the near-infrared excitation characteristic (λex = 980 nm) of HA-UCNPs; upon reaction with hyaluronidase, however, a more than 31-fold fluorescence enhancement is produced. Compared with the corresponding nanosystem assembled via physical adsorption, the prepared nanoprobe shows a largely increased stability and a much higher signal-to-background ratio, which offers an ultrasensitive assay for hyaluronidase, with a detection limit of 0.6 ng/mL. The nanoprobe has been successfully used to determine hyaluronidase in human serum samples from both colorectal cancer patients and healthy people, disclosing that the serum hyaluronidase level in colorectal cancer patients is roughly 3 times higher than that in healthy people. Furthermore, the nanoprobe has also been employed to study the activity change of hyaluronidase affected by different concentrations of arsenate (a potential carcinogen), and the results show that even a low dosage of arsenate (50 μg/L) can raise the activity of hyaluronidase by about one-third, revealing the relationship between arsenate and the enzyme. The proposed method is not only simple but also highly sensitive, making it useful to assay hyaluronidase in relevant clinical samples. PMID:25947627

  5. Biomolecular recognition and detection using gold-based nanoprobes

    NASA Astrophysics Data System (ADS)

    Crew, Elizabeth

    The ability to control the biomolecular interactions is important for developing bioanalytical probes used in biomolecule and biomarker detections. This work aims at a fundamental understanding of the interactions and reactivities involving DNA, miRNA, and amino acids using gold-based nanoparticles as nanoprobes, which has implications for developing new strategies for the early detection of diseases, such as cancer, and controlled delivery of drugs. Surface modifications of the nanoprobes with DNA, miRNA, and amino acids and the nanoprobe directed biomolecular reactivities, such as complementary-strand binding, enzymatic cutting and amino acid interactions, have been investigated. Among various analytical techniques employed for the analysis of the biomolecule-nanoprobe interactions, surface enhanced Raman scattering spectroscopy (SERS) has been demonstrated to provide a powerful tool for real time monitoring of the DNA assembly and enzymatic cutting processes in solutions. This demonstration harnesses the "hot-spot" characteristic tuned by the interparticle biomolecular-regulated interactions and distances. The assembly of gold nanoparticles has also been exploited as sensing thin films on chemiresistor arrays for the detection of volatile organic compounds, including biomarker molecules associated with diabetes. Important findings of the nanoprobes in delivering miRNA to cells, detecting DNA hybridization kinetics, discerning chiral recognition with enantiomeric cysteines, and sensing biomarker molecules with the nanostructured thin films will be discussed, along with their implications to enhancing sensitivity, selectivity and limits of detection.

  6. Multifunctional imaging nanoprobes

    PubMed Central

    Jarzyna, Peter A.; Gianella, Anita; Skajaa, Torjus; Knudsen, Gitte; Deddens, Lisette H.; Cormode, David P.; Fayad, Zahi A.; Mulder, Willem J. M.

    2011-01-01

    Multifunctional imaging nanoprobes have proven to be of great value in the research of pathological processes, as well as the assessment of the delivery, fate, and therapeutic potential of encapsulated drugs. Moreover, such probes may potentially support therapy schemes by the exploitation of their own physical properties, e.g., through thermal ablation. This review will present four classes of nanoparticulate imaging probes used in this area: multifunctional probes (1) that can be tracked with at least three different and complementary imaging techniques, (2) that carry a drug and have bimodal imaging properties, (3) that are employed for nucleic acid delivery and imaging, and (4) imaging probes with capabilities that can be used for thermal ablation. We will highlight several examples where the suitable combination of different (bio)materials like polymers, inorganic nanocrystals, fluorophores, proteins/peptides, and lipids can be tailored to manufacture multifunctional probes to accomplish nanomaterials of each of the aforementioned classes. Moreover, it will be demonstrated how multimodality imaging approaches improve our understanding of in vivo nanoparticle behavior and efficacy at different levels, ranging from the subcellular level to the whole body. PMID:20039335

  7. A symmetrical fluorous dendron-cyanine dye-conjugated bimodal nanoprobe for quantitative 19F MRI and NIR fluorescence bioimaging.

    PubMed

    Wang, Zhe; Yue, Xuyi; Wang, Yu; Qian, Chunqi; Huang, Peng; Lizak, Marty; Niu, Gang; Wang, Fu; Rong, Pengfei; Kiesewetter, Dale O; Ma, Ying; Chen, Xiaoyuan

    2014-08-01

    (19)F MRI and optical imaging are two powerful noninvasive molecular imaging modalities in biomedical applications. (19)F MRI has great potential for high resolution in vivo imaging, while fluorescent probes enable ultracontrast cellular/tissue imaging with high accuracy and sensitivity. A bimodal nanoprobe is developed, integrating the merits of (19)F MRI and fluorescence imaging into a single synthetic molecule, which is further engineered into nanoprobe, by addressing shortcomings of conventional contrast agents to explore the quantitative (19)F MRI and fluorescence imaging and cell tracking. Results show that this bimodal imaging nanoprobe presents high correlation of (19)F MR signal and NIR fluorescence intensity in vitro and in vivo. Additionally, this nanoprobe enables quantitative (19)F MR analysis, confirmed by a complementary fluorescence analysis. This unique feature can hardly be obtained by traditional (19)F MRI contrast agents. It is envisioned that this nanoprobe can hold great potential for quantitative and sensitive multi-modal molecular imaging. PMID:24789108

  8. Quantum dot-labeled aptamer nanoprobes specifically targeting glioma cells

    NASA Astrophysics Data System (ADS)

    Chen, Xue-Chai; Deng, Yu-Lin; Lin, Yi; Pang, Dai-Wen; Qing, Hong; Qu, Feng; Xie, Hai-Yan

    2008-06-01

    Two new techniques, aptamer-based specific recognition and quantum dot (QD)-based fluorescence labeling, are becoming increasingly important in biosensing. In this study, these two techniques have been coupled together to construct a new kind of fluorescent QD-labeled aptamer (QD-Apt) nanoprobe by conjugating GBI-10 aptamer to the QD surface. GBI-10 is a single-stranded DNA (ssDNA) aptamer for tenascin-C, which distributes on the surface of glioma cells as a dominant extracellular matrix protein. The QD-Apt nanoprobe can recognize the tenascin-C on the human glioma cell surface, which will be helpful for the development of new convenient and sensitive in vitro diagnostic assays for glioma. The QD-Apt nanoprobe has particular features such as strong fluorescence, stability, monodispersity and uniformity. In addition, this probe preparation method is universal, so it is expected to provide a new type of stable nanoprobe for high-throughput and fast biosensing detection and bioimaging. New methods for real-time and dynamic tracking and imaging can be accordingly developed.

  9. Observation of Molecular Diffusion in Polyelectrolyte-Wrapped SERS Nanoprobes

    PubMed Central

    2015-01-01

    The popularity of nanotechnology-based sensing technologies has rapidly expanded within the past decade. Surface-enhanced Raman spectroscopy (SERS) is one such technique capable of chemically specific and highly sensitive measurements. The careful preparation of SERS-active nanoprobes is immensely vital for biological applications where nanoprobes are exposed to harsh ionic and protein rich microenvironments. Encapsulation of optical reporter molecules via layer-by-layer (LbL) polyelectrolyte wrapping is an emerging technique that also permits facile modification of surface chemistry and charge. LbL wrapping can be performed within a few hours and does not require the use of organic solvents or hazardous silanes. Nonetheless, the stability of its products requires further characterization and analysis. In this study, Raman-active methylene blue molecules were electrostatically encapsulated within alternating layers of cationic and anionic polyelectrolytes surrounding gold nanospheres. We observed molecular diffusion of methylene blue through polyelectrolyte layers by monitoring the change in SERS intensity over a period of more than 5 weeks. To minimize diffusion and improve the long-term storage stability of our nanoprobes, two additional nanoprobe preparation techniques were performed: thiol coating and cross-linking of the outer polyelectrolyte layer. In both cases, molecular diffusion is significantly diminished. PMID:24998291

  10. Cost-Sensitive Local Binary Feature Learning for Facial Age Estimation.

    PubMed

    Lu, Jiwen; Liong, Venice Erin; Zhou, Jie

    2015-12-01

    In this paper, we propose a cost-sensitive local binary feature learning (CS-LBFL) method for facial age estimation. Unlike the conventional facial age estimation methods that employ hand-crafted descriptors or holistically learned descriptors for feature representation, our CS-LBFL method learns discriminative local features directly from raw pixels for face representation. Motivated by the fact that facial age estimation is a cost-sensitive computer vision problem and local binary features are more robust to illumination and expression variations than holistic features, we learn a series of hashing functions to project raw pixel values extracted from face patches into low-dimensional binary codes, where binary codes with similar chronological ages are projected as close as possible, and those with dissimilar chronological ages are projected as far as possible. Then, we pool and encode these local binary codes within each face image as a real-valued histogram feature for face representation. Moreover, we propose a cost-sensitive local binary multi-feature learning method to jointly learn multiple sets of hashing functions using face patches extracted from different scales to exploit complementary information. Our methods achieve competitive performance on four widely used face aging data sets. PMID:26415174

  11. Partially reduced graphene oxide as highly efficient DNA nanoprobe.

    PubMed

    Wang, Yan-Hong; Deng, Hao-Hua; Liu, Yin-Huan; Shi, Xiao-Qiong; Liu, Ai-Lin; Peng, Hua-Ping; Hong, Guo-Lin; Chen, Wei

    2016-06-15

    This work investigates the effect of reduction degree on graphene oxide (GO)-DNA interaction and the fluorescence quenching mechanism. Partial reduced graphene oxide (pRGO), which maintains well water-dispersibility, is synthesized using a mild reduction method by incubating GO suspension under alkaline condition at room temperature. The fluorescence quenching enhances with the restoration degree of sp(2) carbon bonds and follows the static quenching mechanism. The binding constant values imply that pRGO has much stronger affinity with ssDNA than GO. Utilizing this highly efficient nanoprobe, a universal sensing strategy is proposed for homogeneous detection of DNA. Compared with the reported GO-based DNA, this present strategy has obvious advantages such as requirement of low nanoprobe dosage, significantly reduced background, fast fluorescence quenching, and improved sensitivity. Even without any amplification process, the limit of detection can reach as low as 50 pM. PMID:26826548

  12. Rare Earth Nanoprobes for Functional Biomolecular Imaging and Theranostics

    PubMed Central

    Naczynski, Dominik J.; Tan, Mei Chee; Riman, Richard E.; Moghe, Prabhas V.

    2014-01-01

    Contrast agents designed to visualize the molecular mechanisms underlying cancer pathogenesis and progression have deepened our understanding of disease complexity and accelerated the development of enhanced drug strategies targeted to specific biochemical pathways. For the next generation probes and imaging systems to be viable, they must exhibit enhanced sensitivity and robust quantitation of morphologic and contrast features, while offering the ability to resolve the disease-specific molecular signatures that may be critical to reconstitute a more comprehensive portrait of pathobiology. This feature article provides an overview on the design and advancements of emerging biomedical optical probes in general and evaluates the promise of rare earth nanoprobes, in particular, for molecular imaging and theranostics. Combined with new breakthroughs in nanoscale probe configurations, and improved dopant compositions, and multimodal infrared optical imaging, rare-earth nanoprobes can be used to address a wide variety of biomedical challenges, including deep tissue imaging, real-time drug delivery tracking and multispectral molecular profiling. PMID:24921049

  13. Targeting Angiogenesis Using a C-Type Atrial Natriuretic Factor–Conjugated Nanoprobe and PET

    PubMed Central

    Liu, Yongjian; Pressly, Eric D.; Abendschein, Dana R.; Hawker, Craig J.; Woodard, Geoffrey E.; Woodard, Pamela K.; Welch, Michael J.

    2014-01-01

    Sensitive, specific, and noninvasive detection of angiogenesis would be helpful in discovering new strategies for the treatment of cardiovascular diseases. Recently, we reported the 64Cu-labeled C-type atrial natriuretic factor (CANF) fragment for detecting the upregulation of natriuretic peptide clearance receptor (NPR-C) with PET on atherosclerosis-like lesions in an animal model. However, it is unknown whether NPR-C is present and overexpressed during angiogenesis. The goal of this study was to develop a novel CANF-integrated nanoprobe to prove the presence of NPR-C and offer sensitive detection with PET during development of angiogenesis in mouse hind limb. Methods We prepared a multifunctional, core-shell nanoparticle consisting of DOTA chelators attached to a poly(methyl methacrylate) core and CANF-targeting moieties attached to poly(ethylene glycol) chain ends in the shell of the nanoparticle. Labeling of this nanoparticle with 64Cu yielded a high-specific-activity nanoprobe for PET imaging NPR-C receptor in a mouse model of hind limb ischemia–induced angiogenesis. Histology and immunohistochemistry were performed to assess angiogenesis development and NPR-C localization. Results 15O-H2O imaging showed blood flow restoration in the previously ischemic hind limb, consistent with the development of angiogenesis. The targeted DOTA-CANF-comb nanoprobe showed optimized pharmacokinetics and biodistribution. PET imaging demonstrated significantly higher tracer accumulation for the targeted DOTA-CANF-comb nanoprobe than for either the CANF peptide tracer or the nontargeted control nanoprobe (P < 0.05, both). Immunohistochemistry confirmed NPR-C upregulation in the angiogenic lesion with colocalization in both endothelial and smooth muscle cells. PET and immunohistochemistry competitive receptor blocking verified the specificity of the targeted nanoprobe to NPR-C receptor. Conclusion As evidence of its translational potential, this customized DOTA

  14. Poly(m-phenylenediamine)-based fluorescent nanoprobe for ultrasensitive detection of matrix metalloproteinase 2.

    PubMed

    Wang, Zhe; Li, Xiaohua; Feng, Duan; Li, Lihong; Shi, Wen; Ma, Huimin

    2014-08-01

    A novel fluorescence nanoprobe for the detection of matrix metalloproteinase 2 (MMP2) has been developed by engineering the fluorescein isothiocyanate-labeled peptide onto the surface of poly(m-phenylenediamine) (PMPD) nanoparticles through covalent linkage. The nanoprobe itself displays a low background signal due to the effective fluorescence quenching by electron-rich PMPD, but its reaction with MMP2 causes 11-fold fluorescence enhancement. Compared with similar fluorescence nanosystems for MMP2 assembled through physical adsorption, the as-prepared nanoprobe is significantly more stable and displays a strikingly higher signal-to-background ratio, which leads to a high sensitivity for MMP2 assay, with a detection limit of 32 pM. Most notably, the nanoprobe has been successfully applied to determine MMP2 in human serum samples, demonstrating that the MMP2 level in serum from colorectal cancer (CRC) patients is 2 times higher than that from healthy people. Moreover, the nanoprobe has also been used to monitor MMP2 secreted by CRC cells that were grown under normoxic and hypoxic conditions, respectively, and the results show that the cells under hypoxic conditions produce higher level of MMP2 than those under normoxic conditions. Our method is simple and can offer a highly sensitive detection of MMP2 in relevant clinical samples. PMID:25029076

  15. Two-Dimensional Optoelectronic Graphene Nanoprobes for Neural Nerwork

    NASA Astrophysics Data System (ADS)

    Hong, Tu; Kitko, Kristina; Wang, Rui; Zhang, Qi; Xu, Yaqiong

    2014-03-01

    Brain is the most complex network created by nature, with billions of neurons connected by trillions of synapses through sophisticated wiring patterns and countless modulatory mechanisms. Current methods to study the neuronal process, either by electrophysiology or optical imaging, have significant limitations on throughput and sensitivity. Here, we use graphene, a monolayer of carbon atoms, as a two-dimensional nanoprobe for neural network. Scanning photocurrent measurement is applied to detect the local integration of electrical and chemical signals in mammalian neurons. Such interface between nanoscale electronic device and biological system provides not only ultra-high sensitivity, but also sub-millisecond temporal resolution, owing to the high carrier mobility of graphene.

  16. Quantifying the microvascular origin of BOLD-fMRI from first principles with two-photon microscopy and an oxygen-sensitive nanoprobe.

    PubMed

    Gagnon, Louis; Sakadžić, Sava; Lesage, Frédéric; Musacchia, Joseph J; Lefebvre, Joël; Fang, Qianqian; Yücel, Meryem A; Evans, Karleyton C; Mandeville, Emiri T; Cohen-Adad, Jülien; Polimeni, Jonathan R; Yaseen, Mohammad A; Lo, Eng H; Greve, Douglas N; Buxton, Richard B; Dale, Anders M; Devor, Anna; Boas, David A

    2015-02-25

    The blood oxygenation level-dependent (BOLD) contrast is widely used in functional magnetic resonance imaging (fMRI) studies aimed at investigating neuronal activity. However, the BOLD signal reflects changes in blood volume and oxygenation rather than neuronal activity per se. Therefore, understanding the transformation of microscopic vascular behavior into macroscopic BOLD signals is at the foundation of physiologically informed noninvasive neuroimaging. Here, we use oxygen-sensitive two-photon microscopy to measure the BOLD-relevant microvascular physiology occurring within a typical rodent fMRI voxel and predict the BOLD signal from first principles using those measurements. The predictive power of the approach is illustrated by quantifying variations in the BOLD signal induced by the morphological folding of the human cortex. This framework is then used to quantify the contribution of individual vascular compartments and other factors to the BOLD signal for different magnet strengths and pulse sequences. PMID:25716864

  17. Carbon Dots Embedded Magnetic Nanoparticles @Chitosan @Metal Organic Framework as a Nanoprobe for pH Sensitive Targeted Anticancer Drug Delivery.

    PubMed

    Chowdhuri, Angshuman Ray; Singh, Tanya; Ghosh, Sudip Kumar; Sahu, Sumanta Kumar

    2016-07-01

    Recently, nanoscale metal organic frameworks (NMOFs) have been demonstrated as a promising carrier for drug delivery, as they possess many advantages like large surface area, high porosity, and tunable functionality. However, there are no reports about the functionalization of NMOFs, which combines cancer-targeted drug delivery/imaging, magnetic property, high drug loading content, and pH-sensitive drug release into one system. Existing formulations for integrating target molecules into NMOF are based on multistep synthetic processes. However, in this study, we report an approach that combines NMOF (IRMOF-3) synthesis and target molecule (Folic acid) encapsulation on the surface of chitosan modified magnetic nanoparticles in a single step. A noticeable feature of chitosan is control and pH responsive drug release for several days. More importantly, doxorubicin (DOX) was incorporated into magnetic NMOF formulation and showed high drug loading (1.63 g DOX g(-1) magnetic NMOFs). To demonstrate the optical imaging, carbon dots (CDs) are encapsulated into the synthesized magnetic NMOF, thereby endowing fluorescence features to the nanoparticles. These folate targeted magnetic NMOF possess more specific cellular internalization toward folate-overexpressed cancer (HeLa) cells in comparison to normal (L929) cells. PMID:27305490

  18. Neurotoxin-conjugated upconversion nanoprobes for direct visualization of tumors under near-infrared irradiation.

    PubMed

    Yu, Xue-Feng; Sun, Zhengbo; Li, Min; Xiang, Yang; Wang, Qu-Quan; Tang, Fenfen; Wu, Yingliang; Cao, Zhijian; Li, Wenxin

    2010-11-01

    We report the development of neurotoxin-mediated upconversion nanoprobes for tumor targeting and visualization in living animals. The nanoprobes were synthesized by preparing polyethylenimine-coated hexagonal-phase NaYF(4):Yb,Er/Ce nanoparticles and conjugating them with recombinant chlorotoxin, a typical peptide neurotoxin that could bind with high specificity to many types of cancer cells. Nanoprobes that specifically targeted glioma cells were visualized by laser scanning upconversion fluorescence microscopy. Good probe biocompatibility was displayed with cellular and animal toxicity determinations. Animal studies were performed using Balb-c nude mice injected intravenously with the nanoprobes. The obtained high-contrast images demonstrated highly specific tumor binding and direct tumor visualization with bright red fluorescence under 980-nm near-infrared irradiation. The high sensitivity and high specificity of the neurotoxin-mediated upconversion nanoprobes and the simplification of the required optical device for tumor visualization suggest an approach that may help improve the effectiveness of the diagnostic and therapeutic modalities available for tumor patients. PMID:20728213

  19. Scanning Kelvin nanoprobe detection in materials science and biochemical analysis.

    PubMed

    Cheran, Larisa-Emilia; Sadeghi, Saman; Thompson, Michael

    2005-12-01

    The Kelvin nanoprobe is an extremely sensitive instrument capable of discerning subtle molecular interactions using vibrating electromagnetic and acoustic fields. It is based on the measurement of a fundamental material property, the work function. Modulation of this substrate parameter is caused by the adsorption or desorption of molecules, oxidation, corrosion, contamination, mechanical stress, illumination, temperature changes, electrostatic charging, surface treatment, attached dipolar structures and/or the immobilization of biomolecules. The present article explains the general principles of the method and offers an indication of the wide range of possible applications, with an emphasis on potential use in the biotechnological arena. PMID:16284653

  20. Sensitivity-based adaptive learning rules for binary feedforward neural networks.

    PubMed

    Zhong, Shuiming; Zeng, Xiaoqin; Wu, Shengli; Han, Lixin

    2012-03-01

    This paper proposes a set of adaptive learning rules for binary feedforward neural networks (BFNNs) by means of the sensitivity measure that is established to investigate the effect of a BFNN's weight variation on its output. The rules are based on three basic adaptive learning principles: the benefit principle, the minimal disturbance principle, and the burden-sharing principle. In order to follow the benefit principle and the minimal disturbance principle, a neuron selection rule and a weight adaptation rule are developed. Besides, a learning control rule is developed to follow the burden-sharing principle. The advantage of the rules is that they can effectively guide the BFNN's learning to conduct constructive adaptations and avoid destructive ones. With these rules, a sensitivity-based adaptive learning (SBALR) algorithm for BFNNs is presented. Experimental results on a number of benchmark data demonstrate that the SBALR algorithm has better learning performance than the Madaline rule II and backpropagation algorithms. PMID:24808553

  1. Self-illuminating nanoprobe for in vivo imaging of cancers over-expressing the folate receptor

    NASA Astrophysics Data System (ADS)

    Miller, Steven C.; Beviglia, Lucia; Yeung, Pete; Bhattacharyya, Sukanta; Sobek, Daniel

    2012-03-01

    New in vivo imaging reagents with increased sensitivity and penetration depth are needed to advance our understanding of metastases and accelerate the development of therapeutics. The folate receptor (FR) is a promising imaging target that is up-regulated in many human carcinomas, including cancers of the ovary, breast, pancreas, endometrium, lungs, kidneys, colon, brain, and myeloid cells. Zymera has developed a self-illuminating Bioluminescence Resonance Energy Transfer Quantum Dot (BRET-Qdot) nanoprobe conjugated with folate (BQ-Folate) for in vivo imaging of cancers overexpressing FR. BQ-Folate is a novel nanoprobe formed by co-conjugating Renilla reniformis luciferase enzyme and folate to near-infrared (NIR) emitting quantum dots. The luciferase substrate, coelenterazine, activates the BQ-Folate nanoprobe generating luminescence emission in the near-infrared (NIR) region (655 nm) for increased sensitivity and penetration depth. Because BQ-Folate requires no external light source for light emission, it has significant advantages for challenging in vivo preclinical optical imaging applications, such as the detection of early stage metastases. Zymera and OncoMed Pharmaceuticals have demonstrated that in vivo imaging with the BQ-Folate nanoprobe detected the primary tumor and early stage metastases in an orthotopic NOD/SCID mouse model of human pancreatic cancer.

  2. Off-Resonance Saturation MRI of Superparamagnetic Nanoprobes: Theoretical Models and Experimental Validations

    PubMed Central

    Khemtong, Chalermchai; Togao, Osamu; Ren, Jimin; Kessinger, Chase W.; Takahashi, Masaya; Sherry, A. Dean; Gao, Jinming

    2011-01-01

    Off-resonance saturation (ORS) is a new magnetic resonance imaging (MRI) method that has shown greatly improved contrast sensitivity for the detection of cancer-specific biomarkers by superparamagnetic nanoprobes in vivo. However, quantitative understanding of the ORS contrast mechanism and its dependence on the structural parameters of superparamagnetic nanoprobes are still lacking. Here we propose a quantitative model of ORS contrast and its experimental validation by superparamagnetic polymeric micelles (SPPM) with precisely controlled structural properties. Size selected, monodisperse Fe3O4 nanoparticles (6.1 ± 0.2 nm) were used to form a series of SPPM nanoprobes with specifically controlled corona thickness using 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxypoly(ethylene glycol) (DSPE-PEG) with different PEG molecular weights. Transmission electron microscopy and dynamic light scattering showed that SPPM were uniform in size. The average hydrodynamic diameters of SPPM with PEG lengths of 0.55, 1, 2, and 5 kD were 16.6 ± 2.8, 18.4 ± 2.9, 24.1 ± 3.4, and 28.9 ± 3.4 nm, respectively. MRI experiments at 7T determined that r2 values of SPPM with 0.55, 1, 2, and 5 kD PEG as corona were 201 ± 3, 136 ± 8, 107 ± 5, and 108 ± 8 Fe mM-1s-1, respectively. ORS intensity from Z-spectra of SPPM showed a significant correlation with the inverse of T2 relaxation rates (1/T2, s-1) of the SPPM nanoprobes regardless of the PEG corona thickness. These data provide the fundamental understanding of the structure-property relationships between the SPPM nanostructures and ORS sensitivity, which offers useful mechanistic insights for the future improvement of SPPM nanoprobes in cancer molecular imaging applications. PMID:21277813

  3. Counter electrodes from binary ruthenium selenide alloys for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Li, Pinjiang; Cai, Hongyuan; Tang, Qunwei; He, Benlin; Lin, Lin

    2014-12-01

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its merits on clean, cost-effectiveness, relatively high efficiency, and easy fabrication. However, the reduction of fabrication cost without sacrifice of power conversion efficiencies of the DSSCs is a golden rule for their commercialization. Here we design a new binary ruthenium selenide (Ru-Se) alloy counter electrodes (CEs) by a low-temperature hydrothermal reduction method. The electrochemical behaviors are evaluated by cyclic voltammogram, electrochemical impedance, and Tafel measurements, giving an optimized Ru/Se molar ratio of 1:1. The DSSC device with RuSe alloy CE achieves a power conversion efficiency of 7.15%, which is higher than 5.79% from Pt-only CE based DSSC. The new concept, easy process along with promising results provide a new approach for reducing cost but enhancing photovoltaic performances of DSSCs.

  4. Enzymatically catalytic signal tracing by a glucose oxidase and ferrocene dually functionalized nanoporous gold nanoprobe for ultrasensitive electrochemical measurement of a tumor biomarker.

    PubMed

    Cheng, Hui; Xu, Lingling; Zhang, Haili; Yu, Aimin; Lai, Guosong

    2016-07-21

    A nanoporous gold nanosphere (pAu NS) was synthesized to load high-content glucose oxidase (GOx) and ferrocene (Fc) for the successful preparation of a new gold nanoprobe. After the specific recognition of the tumor biomarker of carcinoembryonic antigen (CEA) at a gold electrode based aptasensor, this GOx and Fc dually functionalized pAu NS nanoprobe was further used for sandwich immunoreaction and signal tracing. Based on the Fc-mediated GOx-catalytic reaction, the gold nanoprobes quantitatively captured onto the electrode surface produced a sensitive electrochemical signal corresponding to the protein recognition events, which led to the development of a new biosensing method for CEA measurement. Both the high loading of GOx and Fc on the pAu NS nanocarrier and the enzymatically catalytic reaction of the nanoprobe greatly amplify the electrochemical signal; meanwhile, the immobilization of the Fc mediator on this enzyme nanoprobe and the highly specific aptamer recognition drastically decrease the background current, resulting in the achievement of ultrahigh sensitivity of the method. Under optimum conditions, this method shows an excellent analytical performance including a wide linear relationship of five-order of magnitude and a low detection limit down to 0.45 pg mL(-1). Thus this pAu NS based gold nanoprobe and the proposed immunoassay method provide great potential for practical applications. PMID:27186605

  5. pHe-induced charge-reversible NIR fluorescence nanoprobe for tumor-specific imaging.

    PubMed

    Dong, Chunhong; Liu, Zhongyun; Zhang, Lei; Guo, Weisheng; Li, Xue; Liu, Junqing; Wang, Hanjie; Chang, Jin

    2015-04-15

    Inspired by the specificity of acid tumor microenvironment, we constructed a flexible charge-reversible near-infrared (NIR) fluorescence nanoprobe in response to tumor extracellular pH (pHe) for effective tumor-specific imaging. The nanoprobe consists of an NIR-emitted CuInS2/ZnS quantum dot (CIS/ZS QDs) core and a tailored lauric acid and 2,3-dimethylmaleic anhydride modified ε-polylysine (ε-PL-g-LA/DMA) shell, which provides not only a dense protective layer for the QDs but also the ability of pHe-induced positive charge-mediated endocytosis into tumor cells. The results showed that the QDs@ε-PL-g-LA/DMA nanoprobe with a uniform size of 40 nm had high chemical stability at pH 7.4 and excellent optical properties. Especially, it swiftly reversed its surface charge to positive in 20 min when exposed to pHe due to the cleavage of the β-carboxyl amide bond of ε-PL-g-LA/DMA. Moreover, the cell uptake of the pHe-sensitive QDs nanoprobe exposed at pH 6.8 into HeLa cells is much more significant than that at pH 7.4, which further verified the availability of the electrostatic adsorptive endocytosis facilitated targeting ability. The pHe-induced targeting imparted the QDs nanoprobe a broad targeting ability in a variety of solid tumors. Furthermore, as an effective alternative mechanism for tumor targeting, responsive charge reversion is also universally applicable to other cancer theranostics agent. PMID:25799279

  6. Sonophoric nanoprobe aided pH measurement in vivo using photoacoustic spectroscopy†

    PubMed Central

    Ray, Aniruddha; Yoon, Hyung Ki; Koo Lee, Yong Eun

    2014-01-01

    Presented here is a novel method of in vivo pH sensing utilizing a hybrid optical imaging technique, photoacoustic imaging (PAI), and pH sensitive polymeric nanoprobes. Nanoprobes with hydrophobic core containing a pH sensitive dye were synthesized and used to measure the pH level ex vivo first and then in vivo by performing experiments on a rat joint model, with an achieved precision of less than 0.1 pH units. The ability of the hydrophobic functional groups in the polyacrylamide matrix to shield the molecular dye from being affected by the proteins in the plasma, and prevent the dye from leaching out, is also demonstrated. PMID:23598348

  7. Sensitivity comparison of searches for binary black hole coalescences with ground-based gravitational-wave detectors

    NASA Astrophysics Data System (ADS)

    Mohapatra, Satya; Cadonati, Laura; Caudill, Sarah; Clark, James; Hanna, Chad; Klimenko, Sergey; Pankow, Chris; Vaulin, Ruslan; Vedovato, Gabriele; Vitale, Salvatore

    2014-07-01

    Searches for gravitational-wave transients from binary black hole coalescences typically rely on one of two approaches: matched filtering with templates and morphology-independent excess power searches. Multiple algorithmic implementations in the analysis of data from the first generation of ground-based gravitational-wave interferometers have used different strategies for the suppression of non-Gaussian noise transients and have targeted different regions of the binary black hole parameter space. In this paper we compare the sensitivity of three such algorithms: matched filtering with full coalescence templates, matched filtering with ringdown templates, and a morphology-independent excess power search. The comparison is performed at a fixed false alarm rate and relies on Monte Carlo simulations of binary black hole coalescences for spinning, nonprecessing systems with a total mass of 25-350 M⊙, which covers a portion of the parameter space of stellar mass and intermediate mass black hole binaries. We find that in the mass range of 25-100 M⊙, the sensitive distance of the search, marginalized over source parameters, is the best with matched filtering to full waveform templates, which is within 10% of the next most sensitive search of morphology-independent excess power algorithm, at a false alarm rate of 3 events/year. In the mass range of 100-350 M⊙, the same comparison favors the morphology-independent excess power search within 20% of matched filtering with ringdown templates. The dependence on mass and spin is also explored.

  8. Plasmonic coupling of dual gold nanoprobes for SERS imaging of sialic acids on living cells.

    PubMed

    Song, Wanyao; Ding, Lin; Chen, Yunlong; Ju, Huangxian

    2016-08-23

    This work reports a benzoic group functionalized gold nanoflower as a bridge probe for both recognition of target sialic acids and assembly of poly(N-acetylneuraminic acid) modified gold nanoparticles, which leads to plasmonic coupling of two kinds of gold nanoprobes in a single-core-multi-satellite nanostructure to produce a sensitive surface-enhanced Raman scattering (SERS) signal for the imaging of sialic acids on living cells. PMID:27500291

  9. A multiplex and straightforward aqueous phase immunoassay protocol through the combination of SERS-fluorescence dual mode nanoprobes and magnetic nanobeads.

    PubMed

    Zong, Shenfei; Wang, Zhuyuan; Zhang, Ruohu; Wang, Chunlei; Xu, Shuhong; Cui, Yiping

    2013-03-15

    A novel aqueous phase immunoassay protocol was demonstrated, using surface enhanced Raman scattering (SERS)-fluorescence dual mode nanoprobes combined with magnetic nanobeads (MBs). Here, the dual mode nanoprobes provide an excellent multiplexing ability while the MBs greatly simplify the immunoassay process. Basically, the nanoprobes were acquired by assembling the Raman reporter tagged Au@Ag core-shell nanorods and quantum dots onto the silica nanospheres. When the specific antigens are presented in the immunoassay system containing antibody modified nanoprobes and MBs, the nanoprobes are captured by the MBs and further precipitated by a magnet. Consequently, both SERS and fluorescence signals are detected in the precipitates. Sandwich type immunoassay was conducted to examine the practicability of this protocol. Experimental results confirmed that the presented immunoassay protocol can accomplish highly specific and sensitive recognition of the target antigens. The detection limit was found out to be 0.1 pg/mL. We anticipate that high throughput bioanalysis can be fulfilled using the proposed immunoassay protocol, as the dual mode nanoprobes provide a great multiplexing capability while the MBs facilitate the convenient aqueous phase detection of the analytes. PMID:23084027

  10. Developing New Nanoprobes from Semiconductor Nanocrystals

    SciTech Connect

    Fu, Aihua

    2006-05-29

    In recent years, semiconductor nanocrystal quantum dots havegarnered the spotlight as an important new class of biological labelingtool. Withoptical properties superior to conventional organicfluorophores from many aspects, such as high photostability andmultiplexing capability, quantum dots have been applied in a variety ofadvanced imaging applications. This dissertation research goes along withlarge amount of research efforts in this field, while focusing on thedesign and development of new nanoprobes from semiconductor nanocrystalsthat are aimed for useful imaging or sensing applications not possiblewith quantum dots alone. Specifically speaking, two strategies have beenapplied. In one, we have taken advantage of the increasing capability ofmanipulating the shape of semiconductor nanocrystals by developingsemiconductor quantum rods as fluorescent biological labels. In theother, we have assembled quantum dots and gold nanocrystals into discretenanostructures using DNA. The background information and synthesis,surface manipulation, property characterization and applications of thesenew nanoprobes in a few biological experiments are detailed in thedissertation.

  11. Perfluoro anion based binary and ternary ionic liquids as electrolytes for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Lin, Hsi-Hsin; Peng, Jia-De; Suryanarayanan, V.; Velayutham, D.; Ho, Kuo-Chuan

    2016-04-01

    In this work, eight new ionic liquids (ILs) based on triethylammonium (TEA) or n-methylpiperidinium (NMP) cations and perfluoro carboxylate (PFC) anions having different carbon chain lengths are synthesized and their physico-chemical properties such as density, decomposition temperature, viscosity and conductivity are determined. Photovoltaic characteristics of dye-sensitized solar cells (DSSCs) with binary ionic liquids electrolytes, containing the mixture of the synthesized ILs and 1-methyl-3-propyl imidazolium iodide (PMII) (v/v = 35/65), are evaluated. Among the different ILs, solar cells containing NMP based ILs show higher VOC than that of TEA, whereas, higher JSC is noted for the DSSCs incorporated with the latter when compared to the former. Further, the photo-current of the DSSCs decreases with the increase of the carbon chain length of perfluoro carboxylate anionic group of ILs. The cell performance of the DSSC containing ternary ionic liquids-based electrolytes compose of NMP-2C/TEA-2C/PMII (v/v/v = 28/7/65) exhibits a JSC of 12.99 mA cm-2, a VOC of 639.0 mV, a FF of 0.72, and a cell efficiency of 6.01%. The extraordinary durability of the DSSC containing the above combination of electrolytes stored in dark at 50 °C is proved to be unfailing up to 1200 h.

  12. Aptamer loaded MoS2 nanoplates as nanoprobes for detection of intracellular ATP and controllable photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Jia, Li; Ding, Lin; Tian, Jiangwei; Bao, Lei; Hu, Yaoping; Ju, Huangxian; Yu, Jun-Sheng

    2015-09-01

    In this work we designed a MoS2 nanoplate-based nanoprobe for fluorescence imaging of intracellular ATP and photodynamic therapy (PDT) via ATP-mediated controllable release of 1O2. The nanoprobe was prepared by simply assembling a chlorine e6 (Ce6) labelled ATP aptamer on MoS2 nanoplates, which have favorable biocompatibility, unusual surface-area-to-mass ratio, strong affinity to single-stranded DNA, and can quench the fluorescence of Ce6. After the nanoprobe was internalized into the cells and entered ATP-abundant lysosomes, its recognition to ATP led to the release of the single-stranded aptamer from MoS2 nanoplates and thus recovered the fluorescence of Ce6 at an excitation wavelength of 633 nm, which produced a highly sensitive and selective method for imaging of intracellular ATP. Meanwhile, the ATP-mediated release led to the generation of 1O2 under 660 nm laser irradiation, which could induce tumor cell death with a lysosomal pathway. The controllable PDT provided a model approach for design of multifunctional theranostic nanoprobes. These results also promoted the development and application of MoS2 nanoplate-based platforms in biomedicine.In this work we designed a MoS2 nanoplate-based nanoprobe for fluorescence imaging of intracellular ATP and photodynamic therapy (PDT) via ATP-mediated controllable release of 1O2. The nanoprobe was prepared by simply assembling a chlorine e6 (Ce6) labelled ATP aptamer on MoS2 nanoplates, which have favorable biocompatibility, unusual surface-area-to-mass ratio, strong affinity to single-stranded DNA, and can quench the fluorescence of Ce6. After the nanoprobe was internalized into the cells and entered ATP-abundant lysosomes, its recognition to ATP led to the release of the single-stranded aptamer from MoS2 nanoplates and thus recovered the fluorescence of Ce6 at an excitation wavelength of 633 nm, which produced a highly sensitive and selective method for imaging of intracellular ATP. Meanwhile, the ATP

  13. Enzymatically catalytic deposition of gold nanoparticles by glucose oxidase-functionalized gold nanoprobe for ultrasensitive electrochemical immunoassay.

    PubMed

    Cheng, Hui; Lai, Guosong; Fu, Li; Zhang, Haili; Yu, Aimin

    2015-09-15

    A novel ultrasensitive immunoassay method was developed by combination of the enzymatically catalytic gold deposition with the prepared gold nanoprobe and the gold stripping analysis at an electrochemical chip based immunosensor. The immunosensor was constructed through covalently immobilizing capture antibody at a carbon nanotube (CNT) modified screen-printed carbon electrode. The gold nanoprobe was prepared by loading signal antibody and high-content glucose oxidase (GOD) on the nanocarrier of gold nanorod (Au NR). After sandwich immunoreaction, the GOD-Au NR nanoprobe could be quantitatively captured onto the immunosensor surface and then induce the deposition of gold nanoparticles (Au NPs) via the enzymatically catalytic reaction. Based on the electrochemical stripping analysis of the Au NR nanocarriers and the enzymatically produced Au NPs, sensitive electrochemical signal was obtained for the immunoassay. Both the GOD-induced deposition of Au NPs by the nanoprobe and the sensitive electrochemical stripping analysis on the CNTs based sensing surface greatly amplified the signal response, leading to the ultrahigh sensitivity of this method. Using carcinoembryonic antigen as a model analyte, excellent analytical performance including a wide linear range from 0.01 to 100 ng/mL and a detection limit down to 4.2 pg/mL was obtained. In addition, this immunosensor showed high specificity and satisfactory reproducibility, stability and reliability. The relatively positive detection potential excluded the conventional interference from dissolved oxygen. Thus this electrochemical chip based immunosensing method provided great potentials for practical applications. PMID:25932794

  14. Improving the sensitivity of a search for coalescing binary black holes with nonprecessing spins in gravitational wave data

    NASA Astrophysics Data System (ADS)

    Privitera, Stephen; Mohapatra, Satyanarayan R. P.; Ajith, Parameswaran; Cannon, Kipp; Fotopoulos, Nickolas; Frei, Melissa A.; Hanna, Chad; Weinstein, Alan J.; Whelan, John T.

    2014-01-01

    We demonstrate for the first time a search pipeline with improved sensitivity to gravitational waves from coalescing binary black holes with spins aligned to the orbital angular momentum by the inclusion of spin effects in the search templates. We study the pipeline recovery of simulated gravitational wave signals from aligned-spin binary black holes added to real detector noise, comparing the pipeline performance with aligned-spin filter templates to the same pipeline with nonspinning filter templates. Our results exploit a three-parameter phenomenological waveform family that models the full inspiral-merger-ringdown coalescence and treats the effect of aligned spins with a single effective spin parameter χ. We construct template banks from these waveforms by a stochastic placement method and use these banks as filters in the recently developed gstlal search pipeline. We measure the observable volume of the analysis pipeline for binary black hole signals with Mtotal and χ ∈[0,0.85]. We find an increase in observable volume of up to 45% for systems with 0.2≤χ≤0.85 with almost no loss of sensitivity to signals with 0≤χ≤0.2. We also show that the use of spinning templates in the search pipeline provides for more accurate recovery of the binary mass parameters as well as an estimate of the effective spin parameter. We demonstrate this analysis on 25.9 days of data obtained from the Hanford and Livingston detectors in LIGO's fifth observation run.

  15. Time-resolved luminescent biosensing based on inorganic lanthanide-doped nanoprobes.

    PubMed

    Zheng, Wei; Tu, Datao; Huang, Ping; Zhou, Shanyong; Chen, Zhuo; Chen, Xueyuan

    2015-03-11

    Time-resolved (TR) photoluminescence (PL) biosensing has been widely adopted in many research and medical institutions. However, commercial molecular TRPL bioprobes like lanthanide (Ln(3+))-chelates suffer from poor photochemical stability and long-term toxicity. Inorganic Ln(3+)-doped nanocrystals (NCs), owing to their superior physicochemical properties over Ln(3+)-chelates, are regarded as a new generation of luminescent nanoprobes for TRPL biosensing. The long-lived PL of Ln(3+)-doped NCs combined with the TRPL technique is able to completely suppress the interference of the short-lived background, resulting in a background-free signal and therefore a remarkable sensitivity for biosensing. In this feature article, we summarize the latest advancements in inorganic Ln(3+)-doped NCs as TRPL nano-bioprobes from their fundamental optical properties to their potential applications for ultrasensitive biodetection and high-resolution bioimaging. Future efforts towards the commercialization of these nanoprobes are also proposed. PMID:25633111

  16. Sharp gold based hybrid nanoprobes for cell imaging through dark-field microscopy

    NASA Astrophysics Data System (ADS)

    Lerouge, Frederic; Navarro, Julien R. G.; Foscan, Monica; Chaput, Frederic; Baldeck, Patrice; Parola, Stéphane

    2015-08-01

    Numerous works are based on the design, the elaboration and the study of the optical properties of gold nanoprobes for potential applications in biotechnologies (bioimaging, biosensing). Among all the possible shapes, it appears that sharp gold nanostructures exhibit interesting features due to the strong filed generated at their tips ends, making them very sensitive to the surrounding medium. Here we describe a complete study of PEGylated gold nanoparticles : nanostars and bipyramids as potential agents for bioimaging. The nanoprobes are first prepared in high yield before functionalization with a biocompatible polymer. Then, the PEGylated gold nanoparticles are incubated with melanoma B16-F10 cells and observed using Dark-field microscopy. Results show that the biocompatible gold nanoparticles are easily internalized and most of them localized within the cells.

  17. SERS nanoprobes for the monitoring of endogenous nitric oxide in living cells.

    PubMed

    Cui, Jing; Hu, Kai; Sun, Jia-Jia; Qu, Lu-Lu; Li, Da-Wei

    2016-11-15

    Nitric Oxide (NO) is a significant gaseous signalling molecule in various pathological and physiological pathways, whereas many of its functions are still ambiguous in part because of the shortage of powerful detection approaches. Herein, we present a type of reaction-based surface-enhanced Raman scattering (SERS) nanoprobes, o-phenylenediamine-modified gold nanoparticles (AuNPs/OPD), to detect the level of the endogenous NO in living cells. The detection is achieved through the SERS variation of AuNPs/OPD caused by the reaction between NO and OPD on the surface of AuNPs. The proposed SERS nanoprobes have a good stability and a rapid response to NO within 30s Moreover, as a result of the reaction specificity coupled with SERS fingerprinting, AuNPs/OPD nanoprobes demonstrate high selectivity towards NO over other biologically relevant species with a sensitivity at 10(-7)M level. Thereby, this SERS strategy can be used for monitoring NO that is endogenously produced in living macrophages, indicating immense potential in studying NO-involved pathophysiological processes in biological systems. PMID:27183283

  18. Multifunctional upconversion nanoprobe for tumor fluorescence imaging and near-infrared thermal therapy

    NASA Astrophysics Data System (ADS)

    Wei, Yanchun; Chen, Qun; Wu, Baoyan; Xing, Da

    2014-09-01

    The combination of diagnostics and therapeutics is growing rapidly in cancer treatment. Here, using upconversion nanoparticles coated with chitosan conjugated with a targeting molecule and loaded with indocyanine green (ICG), an excitation-selectable nanoprobe with highly integrated functionalities, including the emission of visible and near-infrared (NIR) light, strong optical absorption in the NIR region and high photostability was developed. After injected in mice, the nanoprobes targeted to the tumor vascular system. NIR lasers (980 and 808 nm) were then selectively applied to the mice. The results show that, the emitted upconversion fluorescence and NIR fluorescence can be used in a complementary manner for high signal/noise ratio and sensitive tumor imaging for more precise tumor localization; Highly effective photothermal therapy can be realized using 808 nm laser irradiation. The upconversion fluorescence at 654 nm is useful for monitoring treatment effect during thermal therapy. In summary, using the nanoprobes, outstanding therapeutic efficacy could be realized and the nanofabrication strategy would highlight the promise of upconversion nanoparticles in cancer theranostics.

  19. Excitation-Selectable Nanoprobe for Tumor Fluorescence Imaging and Near-Infrared Thermal Therapy.

    PubMed

    Wei, Yanchun; Chen, Qun; Wu, Baoyan; Xing, Da

    2016-01-01

    The combination of diagnostics and therapeutics is growing rapidly in cancer treatment. Here, using upconversion nanoparticles coated with chitosan conjugated with a targeting molecule and loaded with indocyanine green (ICG), we develop an excitation-selectable nanoprobe with highly integrated functionalities, including the emission of visible and near-infrared (NIR) light, strong optical absorption in the NIR region and high photostability. After intravenous injection in tumor bearing mice, the nanoprobes target to the tumor vascular system. NIR lasers (980 and 808 nm) are then selectively applied to the mice. The results show that the emitted upconversion fluorescence and NIR fluorescence can be used in a complementary manner for high signal/noise ratio and sensitive tumor imaging for more precise tumor localization. Highly effective photothermal therapy is realized using 808 nm laser irradiation, and the upconversion fluorescence at 654 nm can be used for monitoring treatment effect during the thermal therapy. In summary, using the nanoprobes, outstanding therapeutic efficacy could be realized through flexible excitation control, precise tumor localization, highly effective photothermal conversion and real-time treatment monitoring. The nanofabrication strategy highlights the promise of nanoparticles in cancer theranostics. PMID:27301175

  20. Construction of LRET-based nanoprobe using upconversion nanoparticles with confined emitters and bared surface as luminophore.

    PubMed

    Li, Zhen; Lv, Songwei; Wang, Yali; Chen, Shiyu; Liu, Zhihong

    2015-03-11

    Upconversion nanoparticles (UCNPs) are promising energy donors for luminescence resonance energy transfer (LRET) and have widely been used to construct nanoprobes. To improve the LRET efficiency, which is currently a limiting factor for UCNPs-based bioassay, we herein propose a strategy to construct LRET-based nanoprobe using UCNPs with confined emitters and bared surface as the luminophore, with Ca(2+) as the proof-of-concept target. The sandwich-structure upconversion nanoparticles (SWUCNPs) are designed with a core-inner shell-outer shell architecture, in which the emitting ions (Ln(3+)) are precisely located in the inner shell near the particle surface, which is close enough to external energy acceptors. The target receptor (Fluo-4) is directly tagged on bared surface of SWUCNPs, which further reduces the donor-to-acceptor distance. Our strategy contributes to significantly improved LRET efficiency and hence affords an ultrahigh sensitivity for Ca(2+) detection. The as-constructed nanoprobe is structurally stable and exhibits good biocompatibility, which ensures uptake and reliable observation in living cells. The nanoprobe can be used for monitoring the different levels of cytosol [Ca(2+)] in living cells. Furthermore, it is applicable in Ca(2+) imaging in mice liver tissues. PMID:25707940

  1. pH-Activatable MnO-Based Fluorescence and Magnetic Resonance Bimodal Nanoprobe for Cancer Imaging.

    PubMed

    Hsu, Benedict You Wei; Ng, Michael; Tan, Aaron; Connell, John; Roberts, Thomas; Lythgoe, Mark; Zhang, Yu; Wong, Siew Yee; Bhakoo, Kishore; Seifalian, Alexander M; Li, Xu; Wang, John

    2016-03-01

    Stimuli-responsive nanoprobes that combine both fluorescence and magnetic resonance imaging (MRI) are anticipated to be highly beneficial for tumor visualization with high imaging sensitivity. By employing an interfacial templating scheme, a pH-activatable fluorescence/MRI dual-modality imaging nanoprobe is successfully developed based on the coencapsulation of MnO nanoparticles and coumarin-545T inside a hybrid silica nanoshell. To promote cancer cell targeting with high-specificity, the nanoprobes are also conjugated with folic acid to establish a greater affinity for cancer cells that over-express folate receptors on their cell membrane. In the new nanosystem, MnO nanoparticles are shown to function as an efficient fluorescence quencher of coumarin-545T prior to cellular uptake. However, fluorescence recovery is achieved upon acidic dissolution of the MnO nanoparticles following receptor-mediated endocytosis into the low pH compartments of the cancer cells. Meanwhile, the Mn(2+) ions thus released are also shown to exert a strong T1 contrast enhancement in the cancer cells. Therefore, by demonstrating the dual-activatable MRI and fluorescence imaging in response to the low pH conditions, it is envisioned that these nanoprobes would have tremendous potential for emerging cancer-imaging modalities such as image-guided cancer therapy. PMID:26895111

  2. Aptamer loaded MoS2 nanoplates as nanoprobes for detection of intracellular ATP and controllable photodynamic therapy.

    PubMed

    Jia, Li; Ding, Lin; Tian, Jiangwei; Bao, Lei; Hu, Yaoping; Ju, Huangxian; Yu, Jun-Sheng

    2015-10-14

    In this work we designed a MoS2 nanoplate-based nanoprobe for fluorescence imaging of intracellular ATP and photodynamic therapy (PDT) via ATP-mediated controllable release of (1)O2. The nanoprobe was prepared by simply assembling a chlorine e6 (Ce6) labelled ATP aptamer on MoS2 nanoplates, which have favorable biocompatibility, unusual surface-area-to-mass ratio, strong affinity to single-stranded DNA, and can quench the fluorescence of Ce6. After the nanoprobe was internalized into the cells and entered ATP-abundant lysosomes, its recognition to ATP led to the release of the single-stranded aptamer from MoS2 nanoplates and thus recovered the fluorescence of Ce6 at an excitation wavelength of 633 nm, which produced a highly sensitive and selective method for imaging of intracellular ATP. Meanwhile, the ATP-mediated release led to the generation of (1)O2 under 660 nm laser irradiation, which could induce tumor cell death with a lysosomal pathway. The controllable PDT provided a model approach for design of multifunctional theranostic nanoprobes. These results also promoted the development and application of MoS2 nanoplate-based platforms in biomedicine. PMID:26367253

  3. A photothermally responsive nanoprobe for bioimaging based on Edman degradation.

    PubMed

    Liu, Yi; Wang, Zhantong; Zhang, Huimin; Lang, Lixin; Ma, Ying; He, Qianjun; Lu, Nan; Huang, Peng; Liu, Yijing; Song, Jibin; Liu, Zhibo; Gao, Shi; Ma, Qingjie; Kiesewetter, Dale O; Chen, Xiaoyuan

    2016-05-19

    A new type of photothermally responsive nanoprobe based on Edman degradation has been synthesized and characterized. Under irradiation by an 808 nm laser, the heat generated by the gold nanorod core breaks the thiocarbamide structure and releases the fluorescent dye Cy5.5 with increased near-infrared (NIR) fluorescence under mild acidic conditions. This RGD modified nanoprobe is capable of fluorescence imaging of ανβ3 over-expressing U87MG cells in vitro and in vivo. This Edman degradation-based nanoprobe provides a novel strategy to design activatable probes for biomedical imaging and drug/gene delivery. PMID:27149392

  4. Fluorescent magnetic hybrid nanoprobe for multimodal bioimaging

    PubMed Central

    Bright, Vanessa

    2011-01-01

    A fluorescent magnetic hybrid imaging nanoprobe (HINP) was fabricated by conjugation of superparamagnetic Fe3O4 nanoparticles and visible light-emitting (~600 nm) fluorescent CdTe/CdS quantum dots (QDs). The assembly strategy used the covalent linking of the oxidized dextran shell of magnetic particles to the glutathione ligands of QDs. Synthesized HINP formed stable water-soluble colloidal dispersions. The structure and properties of the particles were characterized by transmission electron and atomic force microscopy, energy dispersive X-ray analysis and inductively coupled plasma optical emission spectroscopy, dynamic light scattering analysis, optical absorption and photoluminescence spectroscopy, and fluorescent imaging. The luminescence imaging region of the nanoprobe was extended to the near-infrared (NIR) (~800 nm) by conjugation of superparamagnetic nanoparticles with synthesized CdHgTe/CdS QDs. Cadmium, mercury based QDs in HINP can be easily replaced by novel water soluble glutathione stabilized AgInS2/ZnS QDs to present a new class of cadmium-free multimodal imaging agents. Observed NIR photoluminescence of fluorescent magnetic nanocomposites supports their use for bioimaging. The developed HINP provides dual-imaging channels for simultaneous optical and magnetic resonance imaging. PMID:21597146

  5. Identification of Paracoccidioides brasiliensis by gold nanoprobes

    NASA Astrophysics Data System (ADS)

    Martins, Jaciara F. S.; Castilho, Maiara L.; Cardoso, Maria A. G.; Carreiro, Andrea P.; Martin, Airton A.; Raniero, Leandro

    2012-01-01

    Paracoccidioides brasiliensis (P. brasiliensis) is a thermal dimorphic fungus and causal agent of paracoccidioidomycosis. Epidemiological data shows that it is mainly concentrated in Central and South America countries, with most registered cases in Colombia, Brazil, and Venezuela. The histopathological similarity with others fungal infection makes the diagnosis of P. brasiliensis more complicated. Therefore, the aim of this work was to find a positive and negative test for P. brasiliensis using gold nanoprobes as a new tool for P. brasiliensis detection. Gold nanoparticles were synthesized by reduction of gold chloride with sodium citrate. The results of this procedure is a wine-red solution with a maximum absorption in the range of ~520-530nm. A specific P. brasiliensis sequence of oligonucleotide was bonded to the nanoparticles, which maintained the wine-red color. The color changes from red to blue for negative diagnostic and is unchanged for a positive test. The H-bond interaction of DNA with the complementary DNA keeps strands together and forms double helical structure, maintaining the colloid stability. However, for non-complimentary DNA sequence the nanoprobes merge into a cluster, changing the light absorption.

  6. Fluorescent magnetic hybrid nanoprobe for multimodal bioimaging

    NASA Astrophysics Data System (ADS)

    Koktysh, Dmitry; Bright, Vanessa; Pham, Wellington

    2011-07-01

    A fluorescent magnetic hybrid imaging nanoprobe (HINP) was fabricated by the conjugation of superparamagnetic Fe3O4 nanoparticles and visible light emitting (~600 nm) fluorescent CdTe/CdS quantum dots (QDs). The assembly strategy used the covalent linking of the oxidized dextran shell of magnetic particles to the glutathione ligands of QDs. The synthesized HINP formed stable water-soluble colloidal dispersions. The structure and properties of the particles were characterized by transmission electron and atomic force microscopy, energy dispersive x-ray analysis and inductively coupled plasma optical emission spectroscopy, dynamic light scattering analysis, optical absorption and photoluminescence spectroscopy, and fluorescent imaging. The luminescence imaging region of the nanoprobe was extended to the near-infrared (NIR) (~800 nm) by conjugation of the superparamagnetic nanoparticles with synthesized CdHgTe/CdS QDs. Cadmium, mercury based QDs in HINP can be easily replaced by novel water-soluble glutathione stabilized AgInS2/ZnS QDs to present a new class of cadmium-free multimodal imaging agents. The observed NIR photoluminescence of fluorescent magnetic nanocomposites supports their use for bioimaging. The developed HINP provides dual-imaging channels for simultaneous optical and magnetic resonance imaging.

  7. A hard X-ray nanoprobe beamline for nanoscale microscopy

    PubMed Central

    Winarski, Robert P.; Holt, Martin V.; Rose, Volker; Fuesz, Peter; Carbaugh, Dean; Benson, Christa; Shu, Deming; Kline, David; Stephenson, G. Brian; McNulty, Ian; Maser, Jörg

    2012-01-01

    The Hard X-ray Nanoprobe Beamline (or Nanoprobe Beamline) is an X-ray microscopy facility incorporating diffraction, fluorescence and full-field imaging capabilities designed and operated by the Center for Nanoscale Materials and the Advanced Photon Source at Sector 26 of the Advanced Photon Source at Argonne National Laboratory. This facility was constructed to probe the nanoscale structure of biological, environmental and material sciences samples. The beamline provides intense focused X-rays to the Hard X-ray Nanoprobe (or Nanoprobe) which incorporates Fresnel zone plate optics and a precision laser sensing and control system. The beamline operates over X-ray energies from 3 to 30 keV, enabling studies of most elements in the periodic table, with a particular emphasis on imaging transition metals. PMID:23093770

  8. Dextran-based fluorescent nanoprobes for sentinel lymph node mapping.

    PubMed

    Dai, Tingting; Zhou, Shuyan; Yin, Chuyang; Li, Shengli; Cao, Weigang; Liu, Wei; Sun, Kang; Dou, Hongjing; Cao, Yilin; Zhou, Guangdong

    2014-09-01

    Biopsy of sentinel lymph node (SLN) has become a common practice to predict whether tumor metastasis has occurred, so proper SLN positioning tracers are highly required. Due to many drawbacks of SLN tracers currently used, developing ideal, biosafe SLN imaging agents is always an urgent issue. The current study designed a novel fluorescent nanoprobe for accurate SLN mapping. Dextran-based nanogel (DNG) was prepared through a highly efficient self-assembly assisted approach and serves as a multi-functional platform for conjugating wide spectra emitting fluorescent agents. The newly fabricated fluorescent DNG (FDNG) could be designed with optimum size and stable fluorescent intensity for specific SLN imaging. Furthermore, a long-term dynamic course in vivo (from 1 min to 72 h) revealed the satisfactory specificity, sensitivity, and stability for SLN mapping. Most importantly, both in vitro and in vivo evaluations indicated that FDNG had fine biosafety and biocompatibility with lymphatic endothelial cells. All these results supported that FDNG could be used as highly efficient molecular imaging probes for specific, sensitive, stable, non-invasive, and safe SLN mapping, which provides efficient and accurate location for SLN biopsy and thus predicts tumor metastasis as well as directs therapies. Besides, our recent studies further demonstrated that DNG could also serve as a specific and controllable drug carrier, indicating a potential application for specific therapies of various lymph-associated diseases. PMID:24957293

  9. A photothermally responsive nanoprobe for bioimaging based on Edman degradation

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Wang, Zhantong; Zhang, Huimin; Lang, Lixin; Ma, Ying; He, Qianjun; Lu, Nan; Huang, Peng; Liu, Yijing; Song, Jibin; Liu, Zhibo; Gao, Shi; Ma, Qingjie; Kiesewetter, Dale O.; Chen, Xiaoyuan

    2016-05-01

    A new type of photothermally responsive nanoprobe based on Edman degradation has been synthesized and characterized. Under irradiation by an 808 nm laser, the heat generated by the gold nanorod core breaks the thiocarbamide structure and releases the fluorescent dye Cy5.5 with increased near-infrared (NIR) fluorescence under mild acidic conditions. This RGD modified nanoprobe is capable of fluorescence imaging of ανβ3 over-expressing U87MG cells in vitro and in vivo. This Edman degradation-based nanoprobe provides a novel strategy to design activatable probes for biomedical imaging and drug/gene delivery.A new type of photothermally responsive nanoprobe based on Edman degradation has been synthesized and characterized. Under irradiation by an 808 nm laser, the heat generated by the gold nanorod core breaks the thiocarbamide structure and releases the fluorescent dye Cy5.5 with increased near-infrared (NIR) fluorescence under mild acidic conditions. This RGD modified nanoprobe is capable of fluorescence imaging of ανβ3 over-expressing U87MG cells in vitro and in vivo. This Edman degradation-based nanoprobe provides a novel strategy to design activatable probes for biomedical imaging and drug/gene delivery. Electronic supplementary information (ESI) available: HPLC, MS and 1H NMR spectrum. See DOI: 10.1039/c6nr01400c

  10. A General and Facile Strategy to Fabricate Multifunctional Nanoprobes for Simultaneous (19)F Magnetic Resonance Imaging, Optical/Thermal Imaging, and Photothermal Therapy.

    PubMed

    Hu, Gaofei; Li, Nannan; Tang, Juan; Xu, Suying; Wang, Leyu

    2016-09-01

    (19)F magnetic resonance imaging (MRI), due to its high sensitivity and negligible background, is anticipated to be a powerful noninvasive, sensitive, and accurate molecular imaging technique. However, the major challenge of (19)F MRI is to increase the number of (19)F atoms while maintaining the solubility and molecular mobility of the probe. Here, we successfully developed a facile and general strategy to synthesize the multifunctional (19)F MRI nanoprobes by encapsulating the hydrophobic inorganic nanoparticles (NPs) into a hybrid polymer micelle consisting of hydrolysates of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PDTES) and oleylamine-functionalized poly(succinimide) (PSIOAm). Due to their good water dispersibility, excellent molecular mobility resulting from the ultrathin coating, and high (19)F atom numbers, these nanoprobes generate a separate sharp singlet of (19)F nuclear magnetic resonance (NMR) signal (at -82.8 ppm) with half peak width of ∼28 Hz, which is highly applicable for (19)F MRI. Significantly, by varying the inorganic core from metals (Au), oxides (Fe3O4), fluorides (NaYF4:Yb(3+)/Er(3+)), and phosphates (YPO4) to semiconductors (Cu7S4 and Ag2S, ZnS:Mn(2+)) NPs, which renders the nanoprobes' multifunctional properties such as photothermal ability (Au, Cu7S4), magnetism (Fe3O4), fluorescence (ZnS:Mn(2+)), near-infrared (NIR) fluorescence (Ag2S), and upconversion (UC) luminescence. Meanwhile, the as-prepared nanoprobes possess relatively small sizes (about 50 nm), which is beneficial for long-time circulation. The proof-of-concept in vitro (19)F NMR and photothermal ablation of ZnS:Mn(2+)@PDTES/PSIOAm and Cu7S4@PDTES/PSIOAm nanoprobes further suggest that these nanoprobes hold wide potentials for multifunctional applications in biomedical fields. PMID:27534896

  11. Nanoprobes, nanostructured materials and solid state materials

    NASA Astrophysics Data System (ADS)

    Yin, Houping

    2005-07-01

    Novel templates have been developed to prepare nanostructured porous materials through nonsurfactant templated pathway. And new applications of these materials, such as drug delivery and molecular imprinting, have been explored. The relationship between template content and pore structure has been investigated. The composition and pore structures were studied in detail using IR, TGA, SEM, TEM, BET and XRD. The obtained mesoporous materials have tunable diameters in the range of 2--12 nm. Due to the many advantages of this nonsurfactant templated pathway, such as environment friendly and biocompatibility, controlled release of antibiotics in the nanoporous materials were studied. The in vitro release properties were found to depend on the silica structures which were well tuned by varying the template content. A controlled long-term release pattern of vancomycin was achieved when the template content was 30 wt% or lower. Nanoscale electrochemical probes with dimensions as small as 50 nm in diameter and 1--2 mum in length were fabricated using electron beam deposition on the apex of conventional micron size electrodes. The electroactive region was limited to the extreme tip of the nanoprobe by coating with an insulating polymer and re-opening of the coating at the extreme tip. The novel nanoelectrodes thus prepared were employed to probe neurons in mouse brain slice and the results suggest that the nanoprobes were capable of recording neuronal excitatory postsynaptic potential signals. Interesting solid state chemistry was found in oxygenated iron phthalocyanine. Their Mossbauer spectra show the formation of four oxygenated species apart from the unoxygenated parent compound. The oxygen-bridged compounds formed in the solid matrix bear no resemblance to the one formed by solution chemistry. Tentative assignment of species has been made with the help of Mossbauer and IR spectroscopy. An effort to modify aniline trimer for potential nanoelectronics applications and to

  12. Nanoprobe arrays for multiple single cell insertion using heterogeneous nanosphere lithography (HNSL)

    NASA Astrophysics Data System (ADS)

    Seo, Yoon Ho; Kim, Lo Hyun; Kim, Young-Beom; Ryu, Wonhyoung

    2013-08-01

    Nanoprobe arrays for multiple single cell insertion were developed using heterogeneous nanosphere lithography. Using two heterogeneous nanoparticles as sacrificial and masking particles, high aspect ratio Si nanoprobes were fabricated in an array with spacing between the nanoprobes ranging from a few to tens of micrometers. For registered single cell analysis, multiple and precise insertion of nanoprobes into multiple single cells in a parallel fashion was demonstrated using micropipette suction and micromanipulators.

  13. A pH-sensitive binary drug delivery system based on poly(caprolactone)-heparin conjugates.

    PubMed

    Ye, Lin; Gao, Zemin; Zhou, Yu; Yin, Xuan; Zhang, Xinpeng; Zhang, Aiying; Feng, Zengguo

    2014-03-01

    PCL-heparin conjugates were synthesized by coupling mono-hydroxyl terminated PCL (Mn = 2000-10000 g/mol) with heparin via EDC/NHS chemistry. The conjugates enabled to self-assemble into the core-shell nanoparticles in around 100 nm diameter to load binary anti-cancer drugs. Lipophilic and neutral paclitaxel (PTX) was first encapsulated in the core, and then hydrophilic and positive charged doxorubicin (DOX) was incorporated into the negative charged shell of PTX loaded nanoparticles via the electrostatic interaction. The in vitro release profiles of the binary-drug loaded nanoparticles revealed that both PTX and DOX were sustainably released from the particles but behaved differently. The release of DOX was pH dependent, ensuring more drug to be released in the tumor cells than in the normal ones. Hence these particles were featured by a sequential controlled drug delivery behavior with a significant cytotoxicity to cervical cancer (Hela cell) and breast cancer (MDA-MB-321) cells. The CLSM observations clearly indicated that both loaded PTX and DOX aggregated in the nucleus of tumor cells to exert their anti-tumor pharmacodynamic effect on the cells. PMID:23554308

  14. Directed searches for continuous gravitational waves from binary systems: Parameter-space metrics and optimal Scorpius X-1 sensitivity

    NASA Astrophysics Data System (ADS)

    Leaci, Paola; Prix, Reinhard

    2015-05-01

    We derive simple analytic expressions for the (coherent and semicoherent) phase metrics of continuous-wave sources in low-eccentricity binary systems for the two regimes of long and short segments compared to the orbital period. The resulting expressions correct and extend previous results found in the literature. We present results of extensive Monte Carlo studies comparing metric mismatch predictions against the measured loss of detection statistics for binary parameter offsets. The agreement is generally found to be within ˜10 %- 30 % . For an application of the metric template expressions, we estimate the optimal achievable sensitivity of an Einstein@Home directed search for Scorpius X-1, under the assumption of sufficiently small spin wandering. We find that such a search, using data from the upcoming advanced detectors, would be able to beat the torque-balance level [R. V. Wagoner, Astrophys. J. 278, 345 (1984); L. Bildsten, Astrophys. J. 501, L89 (1998).] up to a frequency of ˜500 - 600 Hz , if orbital eccentricity is well constrained, and up to a frequency of ˜160 - 200 Hz for more conservative assumptions about the uncertainty on orbital eccentricity.

  15. Balance between the physical diffusion and the exchange reaction on binary ionic liquid electrolyte for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Hao, Feng; Lin, Hong; Zhang, Jing; Li, Jianbao

    A comprehensive characterizations of viscosities, conductivities, triiodide diffusion coefficients, charge-transfer resistances and photovoltaic performance of a potential dye-sensitized solar cell (DSC) electrolyte systems based on binary ionic liquid (IL) mixtures, namely, 1-ethyl-3-methylimidazolium dicyanamide (EMIDCA)/1-methyl-3-propylimidazolium iodide (PMII) with a fixed iodine concentration at varying EMIDCA volume fraction are investigated in the present study. Viscosity and conductivity values are accurately correlated with regard to temperature and EMIDCA volume fraction. The triiodide diffusion coefficients, the predominant electrolyte parameter for limitation of DSC efficiency, are determined by symmetrical cell methods. The physical diffusion and exchange reactions between the iodide and triiodide dominate the apparent triiodide diffusion coefficients at different range of EMIDCA volume fraction. A balance between the viscosity-dependent physical diffusion and the exchange reactions can get at an optimal volume percents of EMIDCA. Impedance spectroscopy and photovoltaic results both support the existence of an optimized binary IL electrolyte composition. Hence, for optimizing an IL-based electrolyte in regards to triiodide transport, a low viscosity is not the exclusive crucial factor since exchange reactions transport effects also play an important role to resolve the diffusion limitation of DSC efficiency.

  16. Upconversion nanoprobes for efficiently in vitro imaging reactive oxygen species and in vivo diagnosing rheumatoid arthritis.

    PubMed

    Chen, Zhaowei; Liu, Zhen; Li, Zhenhua; Ju, Enguo; Gao, Nan; Zhou, Li; Ren, Jinsong; Qu, Xiaogang

    2015-01-01

    Over-generation of reactive oxygen species (ROS) is closely associated with the biological processes of rheumatoid arthritis (RA). Thus, efficient monitoring ROS in inflammatory joints would be essential for better understanding the pathogenesis and optimizing therapeutic interventions. Herein, we designed a ratiometric nanoprobe utilizing upconversion nanoparticles (UCNPs) conjugated with chromophore labeled hyaluronic acid (HA) for high sensitively sensing ROS in the aqueous solution, bioimaging ROS in inflammatory mimic cells and diagnosing RA in vivo. In this approach, the conjugation of HA conferred UCNPs not only water solubility but also biocompatibility and ROS recognizing properties. Particularly, the HA backbone cleavage and detachment of chromophore labeled HA fragments from UCNPs induced by ROS inhibited the luminescent energy transfer (LRET) and allowed rational metric upconversion luminescence (UCL) emission as the detection signal. Importantly, the upconversion nanoprobe showed high effectiveness for early assessing the treatment response of arthritic animals to an antiarthritic drug-methotrexate (MTX). PMID:25477167

  17. Multiplex acute leukemia cytosensing using multifunctional hybrid electrochemical nanoprobes at a hierarchically nanoarchitectured electrode interface

    NASA Astrophysics Data System (ADS)

    Zheng, Tingting; Tan, Tingting; Zhang, Qingfeng; Fu, Jia-Ju; Wu, Jia-Jun; Zhang, Kui; Zhu, Jun-Jie; Wang, Hui

    2013-10-01

    We have developed a robust, nanobiotechnology-based electrochemical cytosensing approach with high sensitivity, selectivity, and reproducibility toward the simultaneous multiplex detection and classification of both acute myeloid leukemia and acute lymphocytic leukemia cells. The construction of the electrochemical cytosensor involves the hierarchical assembly of dual aptamer-functionalized, multilayered graphene-Au nanoparticle electrode interface and the utilization of hybrid electrochemical nanoprobes co-functionalized with redox tags, horseradish peroxidase, and cell-targeting nucleic acid aptamers. The hybrid nanoprobes are multifunctional, capable of specifically targeting the cells of interest, amplifying the electrochemical signals, and generating distinguishable signals for multiplex cytosensing. The as-assembled electrode interface not only greatly facilitates the interfacial electron transfer process due to its high conductivity and surface area but also exhibits excellent biocompatibility and specificity for cell recognition and adhesion. A superstructured sandwich-type sensor geometry is adopted for electrochemical cytosensing, with the cells of interest sandwiched between the nanoprobes and the electrode interface. Such an electrochemical sensing strategy allows for ultrasensitive, multiplex acute leukemia cytosensing with a detection limit as low as ~350 cells per mL and a wide linear response range from 5 × 102 to 1 × 107 cells per mL for HL-60 and CEM cells, with minimal cross-reactivity and interference from non-targeting cells. This electrochemical cytosensing approach holds great promise as a new point-of-care diagnostic tool for early detection and classification of human acute leukemia and may be readily expanded to multiplex cytosensing of other cancer cells.We have developed a robust, nanobiotechnology-based electrochemical cytosensing approach with high sensitivity, selectivity, and reproducibility toward the simultaneous multiplex

  18. Photoacoustics and fluorescence based nanoprobes towards functional and structural imaging in vivo

    NASA Astrophysics Data System (ADS)

    Ray, Aniruddha

    Imaging of chemical analytes and structural properties related to physiological activities within biological systems is of great bio-medical interest; it can contribute to the fundamental understanding of biological systems and can be applied to the diagnosis and prognosis of diseases, especially tumors. The work presented in this thesis focuses on the development and application of polymeric nanoprobe aided optical imaging of chemical analytes (Oxygen, pH) and structural properties in live cells and animal models. To this end, specific nanoprobes, based on the polyacrylamide nanoplatform, bearing both appropriate targeting functionalities, and high concentrations of sensing and contrast agents, have been developed. The nanoprobes presented here are biodegradable, biocompatible and non-toxic, rendering them safe for in vivo use. Furthermore the nanoprobes are designed to have variable optical properties that are dependent on the local concentration of the specific analyte of interest. Optical imaging techniques that are particularly suited for deep tissue applications, such as two-photon fluorescence and photoacoustics, were applied for non-invasive real-time imaging and sensing in cancer cells, tumor spheroids and animal models. Our results demonstrate that this technique enables high sensitive detection of chemical analytes with a sensitivity of <5 Torr for oxygen and <0.1 pH units in vivo, which is better than the currently available in vivo functional imaging techniques. This non-invasive and non-ionizing, yet low cost, method will enable morphological and functional evaluation across any tissue, with both high spatial and temporal resolution but without eliciting short- or long-term tissue damage. Currently no gold standard exists for such xii functional imaging. The approach presented here can be used for early detection and diagnosis of tumors, as well as for monitoring the progression of disease and therapy. This technique will also enable observing

  19. Detection and quantification of alternative splice sites in Arabidopsis genes AtDCL2 and AtPTB2 with highly sensitive surface enhanced Raman spectroscopy (SERS) and gold nanoprobes.

    PubMed

    Kadam, Ulhas S; Schulz, Burkhard; Irudayaraj, Joseph

    2014-05-01

    Alternative splicing (AS) increases the size of the transcriptome and proteome to enhance the physiological capacity of cells. We demonstrate surface enhanced Raman spectroscopy (SERS) in combination with a DNA hybridization analytical platform to identify and quantify AS genes in plants. AS in AtDCL2 and AtPTB2 were investigated using non-fluorescent Raman probes using a 'sandwich assay'. Utilizing Raman probes conjugated to gold nanoparticles we demonstrate the recognition of RNA sequences specific to AtDCL2 and AtPTB2 splice junction variants with detection sensitivity of up to 0.1 fM. PMID:24631541

  20. Nanofiber-net-binary structured membranes for highly sensitive detection of trace HCl gas.

    PubMed

    Wang, Xianfeng; Wang, Jialin; Si, Yang; Ding, Bin; Yu, Jianyong; Sun, Gang; Luo, Wenjing; Zheng, Gang

    2012-12-01

    This work describes the detection of trace hydrogen chloride (HCl) gas through analyses of the resonance frequency signal from quartz crystal microbalance (QCM) sensors coated with polyaniline (PANI) functionalized polyamide 6 (PA 6) (PANI-PA 6) nanofiber-net-binary (NNB) structured membranes. The PA 6 NNB substrate comprising nanofibers and spider-web-like nano-nets fabricated by a versatile electro-spinning/netting (ESN) process offered an ideal interface for the uniform PANI functionalization and enhanced sensing performance. Benefiting from the large specific surface area, high porosity, and strong adhesive force to the QCM electrode of the PANI-PA 6 NNB membranes, the developed HCl-selective sensors exhibited a rapid response, good reproducibility and stability, and low detection limit (7 ppb) at room temperature. Additionally, the PANI-PA 6 NNB sensing membranes presented visible color changes upon cycled exposure to HCl and ammonia, suggesting their potential application in the development of colorimetric sensors. The PANI-PA 6 NNB coated QCM sensors are considered to be a promising candidate for trace HCl gas detection in practical applications. PMID:23108331

  1. Silica-based nanoprobes for biomedical imaging and theranostic applications†

    PubMed Central

    Vivero-Escoto, Juan L.; Huxford-Phillips, Rachel C.

    2013-01-01

    Nanoparticle-based contrast agents are attracting a great deal of attention for various biomedical imaging and theranostic applications. Compared to conventional contrast agents, nanoparticles possess several potential advantages to improve in vivo detection and to enhance targeting efficiency. Silica-based nanoprobes can be engineered to achieve longer blood circulation times, specific clearance pathways, and multivalent binding. In this tutorial review, we summarize the latest progress on designing silica-based nanoprobes for imaging and theranostic applications. The synthesis of both solid silica and mesoporous silica nanoparticles is described, along with different approaches used for surface functionalization. Special emphasis is placed on the application of silica-based nanoprobes in optical, magnetic resonance, and multimodal imaging. The latest breakthroughs in the applications of silica nanoparticles as theranostic agents are also highlighted. PMID:22234515

  2. MoS2-based nanoprobes for detection of silver ions in aqueous solutions and bacteria.

    PubMed

    Yang, Yu; Liu, Teng; Cheng, Liang; Song, Guosheng; Liu, Zhuang; Chen, Meiwan

    2015-04-15

    Silver as an extensively used antibacterial agent also poses potential threats to the environment and human health. Hence, in this work, we design a fluorescent nanoprobe by using rhodamine B isothiocyanate (RhoBS) adsorbed MoS2 nanosheets to realize sensitive and selective detection of Ag(+). On the surface of RhoBS-loaded MoS2 nanosheets, Ag(+) can be reduced to Ag nanoparticles, which afterward could not only lead to the detachment of RhoBS molecules and thus their recovered fluorescence but also the surface-enhanced fluorescence from RhoBS remaining adsorbed on MoS2. Such an interesting mechanism allows highly sensitive detection of Ag(+) (down to 10 nM) with great selectivity among other metal ions. Moreover, we further demonstrate that our MoS2-RhoBS complex could act as a nontoxic nanoprobe to detect Ag(+) in live bacteria samples. Our work resulted from an unexpected finding and suggests the promise of two-dimensional transition-metal sulfide nanosheets as a novel platform for chemical and biological sensing. PMID:25776005

  3. Aptamer-modified magnetic nanoprobe for molecular MR imaging of VEGFR2 on angiogenic vasculature

    NASA Astrophysics Data System (ADS)

    Kim, Bongjune; Yang, Jaemoon; Hwang, Myeonghwan; Choi, Jihye; Kim, Hyun-Ouk; Jang, Eunji; Lee, Jung Hwan; Ryu, Sung-Ho; Suh, Jin-Suck; Huh, Yong-Min; Haam, Seungjoo

    2013-09-01

    Nucleic acid-based aptamers have been developed for the specific delivery of diagnostic nanoprobes. Here, we introduce a new class of smart imaging nanoprobe, which is based on hybridization of a magnetic nanocrystal with a specific aptamer for specific detection of the angiogenic vasculature of glioblastoma via magnetic resonance (MR) imaging. The magnetic nanocrystal imaging core was synthesized using the thermal decomposition method and enveloped by carboxyl polysorbate 80 for water solubilization and conjugation of the targeting moiety. Subsequently, the surface of the carboxylated magnetic nanocrystal was modified with amine-functionalized aptamers that specifically bind to the vascular growth factor receptor 2 (VEGFR2) that is overexpressed on angiogenic vessels. To assess the targeted imaging potential of the aptamer-conjugated magnetic nanocrystal for VEGFR2 markers, the magnetic properties and MR imaging sensitivity were investigated using the orthotopic glioblastoma mouse model. In in vivo tests, the aptamer-conjugated magnetic nanocrystal effectively targeted VEGFR2 and demonstrated excellent MR imaging sensitivity with no cytotoxicity.

  4. An Ultrasensitive Chemiluminescence Biosensor for Carcinoembryonic Antigen Based on Autocatalytic Enlargement of Immunogold Nanoprobes

    PubMed Central

    Hao, Minjia; Ma, Zhanfang

    2012-01-01

    A sensitive flow injection chemiluminescence assay for carcinoembryonic antigen (CEA) detection based on signal amplification with gold nanoparticles (NPs) is reported in the present work. The sandwich system of CEA/anti-CEA/goat-anti-mouse IgG functionalized Au nanoparticles was used as the sensing platform. In order to improve detection sensitivity, a further gold enlargement step was developed based on the autocatalytic Au deposition of gold nanoprobes via the reduction of AuCl4− to Au0 on their surface in the presence of NH2OH·HCl. AuCl4−, which is a soluble product of gold nanoprobes, served as an analyte in the CL reaction for the indirect measurement of CEA. Under optimized conditions, the CL intensity of the system was linearly related to the logarithm of CEA concentration in the range of 100 pg·mL−1 to 1,000 ng·mL−1, with a detection limit of 20 pg·mL−1. PMID:23443399

  5. Bacteriophage-based nanoprobes for rapid bacteria separation

    NASA Astrophysics Data System (ADS)

    Chen, Juhong; Duncan, Bradley; Wang, Ziyuan; Wang, Li-Sheng; Rotello, Vincent M.; Nugen, Sam R.

    2015-10-01

    The lack of practical methods for bacterial separation remains a hindrance for the low-cost and successful development of rapid detection methods from complex samples. Antibody-tagged magnetic particles are commonly used to pull analytes from a liquid sample. While this method is well-established, improvements in capture efficiencies would result in an increase of the overall detection assay performance. Bacteriophages represent a low-cost and more consistent biorecognition element as compared to antibodies. We have developed nanoscale bacteriophage-tagged magnetic probes, where T7 bacteriophages were bound to magnetic nanoparticles. The nanoprobe allowed the specific recognition and attachment to E. coli cells. The phage magnetic nanprobes were directly compared to antibody-conjugated magnetic nanoprobes. The capture efficiencies of bacteriophages and antibodies on nanoparticles for the separation of E. coli K12 at varying concentrations were determined. The results indicated a similar bacteria capture efficiency between the two nanoprobes.The lack of practical methods for bacterial separation remains a hindrance for the low-cost and successful development of rapid detection methods from complex samples. Antibody-tagged magnetic particles are commonly used to pull analytes from a liquid sample. While this method is well-established, improvements in capture efficiencies would result in an increase of the overall detection assay performance. Bacteriophages represent a low-cost and more consistent biorecognition element as compared to antibodies. We have developed nanoscale bacteriophage-tagged magnetic probes, where T7 bacteriophages were bound to magnetic nanoparticles. The nanoprobe allowed the specific recognition and attachment to E. coli cells. The phage magnetic nanprobes were directly compared to antibody-conjugated magnetic nanoprobes. The capture efficiencies of bacteriophages and antibodies on nanoparticles for the separation of E. coli K12 at varying

  6. Highly stable SERS pH nanoprobes produced by co-solvent controlled AuNP aggregation.

    PubMed

    Wei, Haoran; Willner, Marjorie R; Marr, Linsey C; Vikesland, Peter J

    2016-08-15

    Production of gold nanoparticle (AuNP) surface-enhanced Raman spectroscopy (SERS) nanoprobes requires replicable aggregation to produce multimers with high signal intensity. Herein, we illustrate a novel, yet simple, approach to produce SERS nanoprobes through control of co-solvent composition. AuNP multimers were produced by mixing AuNP monomers in water : ethanol co-solvent for variable periods of time. By varying the water : ethanol ratio and the amount of 4-mercaptobenzoic acid (4-MBA) present, the aggregation rate can be systematically controlled. Thiolated poly(ethylene glycol) was then added to halt the aggregation process and provide steric stability. This approach was used to produce pH nanoprobes with excellent colloidal stability in high ionic strength environments and in complex samples. The pH probe exhibits broad pH sensitivity over the range 6-11 and we calculate that a single AuNP dimer in a 35 fL volume is sufficient to generate a detectable SERS signal. As a proof-of-concept, the probes were used to detect the intracellular pH of human prostate cancer cells (PC-3). The internalized probes exhibit a strong 4-MBA signal without any interfering bands from either the cells or the culture media and produce exceptionally detailed pH maps. pH maps obtained from 19 xy surface scans and 14 yz depth scans exhibit highly consistent intracellular pH in the range of 5 to 7, thus indicating the greater reliability and reproducibility of our pH probes compared with other probes previously reported in the literature. Our water : ethanol co-solvent production process is fast, simple, and efficient. Adjustment of solvent composition may become a powerful way to produce SERS tags or nanoprobes in the future. PMID:27143623

  7. The sensitivity of Daphnia magna and Daphnia curvirostris to 10 veterinary antibacterials and to some of their binary mixtures.

    PubMed

    Dalla Bona, Mirco; Di Leva, Vincenzo; De Liguoro, Marco

    2014-11-01

    Aim of this study was to evaluate the suitability of Daphnia curvirostris for the acute toxicity test usually performed on Daphnia magna, and to compare the sensitivity of the two species toward 10 antibacterials [enrofloxacin (EFX), ciprofloxacin(CPX), sulfaguanidine (SGD), sulfadiazine (SDZ), sulfamethazine (SMZ), sulfaquinoxaline (SQO), sulfaclozine (SCZ), sulfamerazine (SMA), sulfadimethoxine (SDM) and trimethoprim (TMP)] and some of their binary mixtures. Furthermore, a tentative prolonged-toxicity test (lasting 13d) was settled up in order to evidence toxic responses with drug concentrations that were uneffective in the classic 48h immobilization test. Results showed that D. curvirostris was more sensitive than D. magna to the majority of compounds (6 out of 10). Lowest 48h EC50s were obtained with EFX (4.3mgL(-1) in D. curvirostris) and SGD (6.2mgL(-1) in D. magna). The toxicity of paired compounds was always concentration-additive or less than concentration-additive. In the prolonged-toxicity test mortality and/or reproduction inhibition were constantly observed. It was concluded that: (1) D. curvirostris could be a suitable model for the evaluation of acute toxicity of antibacterials since its sensitivity was generally greater than that of D. magna; (2) the toxicity of EFX and SGD should be given special attention as the two compounds, in the prolonged test, showed to be active at concentrations of 0.9mgL(-1) and 2.5mgL(-1), respectively; (3) the concentration addition is usually a reasonable worst case estimation of the environmental impact of antibacterial mixtures. PMID:24630458

  8. In vivo tumor-targeted dual-modal fluorescence/CT imaging using a nanoprobe co-loaded with an aggregation-induced emission dye and gold nanoparticles.

    PubMed

    Zhang, Jimei; Li, Chan; Zhang, Xu; Huo, Shuaidong; Jin, Shubin; An, Fei-Fei; Wang, Xiaodan; Xue, Xiangdong; Okeke, C I; Duan, Guiyun; Guo, Fengguang; Zhang, Xiaohong; Hao, Jifu; Wang, Paul C; Zhang, Jinchao; Liang, Xing-Jie

    2015-02-01

    As an intensely studied computed tomography (CT) contrast agent, gold nanoparticle has been suggested to be combined with fluorescence imaging modality to offset the low sensitivity of CT. However, the strong quenching of gold nanoparticle on fluorescent dyes requires complicated design and shielding to overcome. Herein, we report a unique nanoprobe (M-NPAPF-Au) co-loading an aggregation-induced emission (AIE) red dye and gold nanoparticles into DSPE-PEG(2000) micelles for dual-modal fluorescence/CT imaging. The nanoprobe was prepared based on a facile method of "one-pot ultrasonic emulsification". Surprisingly, in the micelles system, fluorescence dye (NPAPF) efficiently overcame the strong fluorescence quenching of shielding-free gold nanoparticles and retained the crucial AIE feature. In vivo studies demonstrated the nanoprobe had superior tumor-targeting ability, excellent fluorescence and CT imaging effects. The totality of present studies clearly indicates the significant potential application of M-NPAPF-Au as a dual-modal non-invasive fluorescence/X-ray CT nanoprobe for in vivo tumor-targeted imaging and diagnosis. PMID:25542798

  9. Multifunctional Nanoprobes for Cancer Cell Targeting, Imaging and Anticancer Drug Delivery

    NASA Astrophysics Data System (ADS)

    Linkov, Pavel; Laronze-Cochard, Marie; Sapi, Janos; Sidorov, Lev N.; Nabiev, Igor

    The diagnosis and treatment of cancer have been greatly improved with recent developments in bio-nanotechnology, including engineering of multifunctional probes. One of the promising nanoscale tools for cancer imaging is fluorescent quantum dots (QDs), whose small size and unique optical properties allow them to penetrate into cells and ensure highly sensitive optical diagnosis of cancer at the cellular level. Furthermore, novel multi-functional probes have been developed in which QDs are conjugated with one or several functional molecules, including targeting moieties and therapeutic agents. Here, the strategy for engineering novel nanocarriers for controlled nucleus-targeted antitumor drug delivery and real-time imaging by single- or two-photon microscopy is described. A triple multifunctional nanoprobe is being developed that consists of a nitrogen-based heterocyclic derivative, an anticancer agent interacting with a DNA in living cells; a recognized molecule serving as a vector responsible for targeted delivery of the probe into cancer cells; and photoluminescent QDs providing the imaging capability of the probe. Subsequent optimization of the multifunctional nanoprobe will offer new possibilities for cancer diagnosis and treatment.

  10. A turn-on fluorescent nanoprobe for selective determination of selenium(IV).

    PubMed

    Liang, Song; Chen, Jiao; Pierce, David T; Zhao, Julia Xiaojun

    2013-06-12

    A turn-on fluorescent nanoprobe was developed for selective determination of selenium(IV). A trace amount of selenium, as an essential nutrient, plays an important role in human health. It has been proven that a selenium deficiency will result in serious health problems. The developed nanoprobe is capable of in situ detection of selenium with target-induced signaling, and no separation step is needed. The nanoprobe consists of a silica nanoparticle core and a coating layer containing selenium(IV)-induced fluorescent molecules, 3,3'-diaminobenzidine (DAB). The nanoprobes have no fluorescence signals if they are not exposed to selenium(IV). However, the nanoprobes will be "turned on", with fluorescence, when they bind to the targets of selenium(IV). With this strategy, the selenium(IV) are first collected and enriched on a small domain of the nanoprobes. Then, with an excitation at 420 nm, the nanoprobes emit fluorescence signals at 530 nm. The fluorescence intensity is proportional to the selenium concentration. A fluorescence microscope was used to monitor the process of enriching and collecting of the selenium(IV) by the nanoprobes. The optimal conditions for the determination of selenium(IV) using the nanoprobe were investigated including pH, solvent, and linear range. The interference from common metal ions was studied as well. This study is expected to shed light on how to design turn-on fluorescent nanoprobes for in situ monitoring of a wide variety of targets in biological processes. PMID:23676764

  11. Design and assembly of supramolecular dual-modality nanoprobes

    NASA Astrophysics Data System (ADS)

    Liu, Shuang; Zhang, Pengcheng; Ray Banerjee, Sangeeta; Xu, Jiadi; Pomper, Martin G.; Cui, Honggang

    2015-05-01

    We report the design and synthesis of self-assembling dual-modality molecular probes containing both a fluorophore for optical imaging and a metal ion chelator for imaging with MRI or radionuclide methods. These molecular probes can spontaneously associate into spherical nanoparticles under physiological conditions. We demonstrate the use of these supramolecular nanoprobes for live-cell optical imaging, as well as their potential use as MRI contrast agents after complexation with gadolinium. Our results suggest that self-assembly into supramolecular nanoprobes presents an effective means to enhance and tune the relaxivities of molecular probes.We report the design and synthesis of self-assembling dual-modality molecular probes containing both a fluorophore for optical imaging and a metal ion chelator for imaging with MRI or radionuclide methods. These molecular probes can spontaneously associate into spherical nanoparticles under physiological conditions. We demonstrate the use of these supramolecular nanoprobes for live-cell optical imaging, as well as their potential use as MRI contrast agents after complexation with gadolinium. Our results suggest that self-assembly into supramolecular nanoprobes presents an effective means to enhance and tune the relaxivities of molecular probes. Electronic supplementary information (ESI) available: Experimental methods, materials, synthesis schemes, sample characterization, fluorescence measurements, cellular uptake and MRI experimental details. See DOI: 10.1039/c5nr01518a

  12. An ultrasmall and metabolizable PEGylated NaGdF4:Dy nanoprobe for high-performance T1/T2-weighted MR and CT multimodal imaging

    NASA Astrophysics Data System (ADS)

    Jin, Xiaoying; Fang, Fang; Liu, Jianhua; Jiang, Chunhuan; Han, Xueli; Song, Zhongkai; Chen, Jinxing; Sun, Guoying; Lei, Hao; Lu, Lehui

    2015-09-01

    Lanthanide-based multimodal probes with high sensitivity, simple synthesis strategy, and good biocompatibility promise new applications for clinical diagnosis. However, today's challenge is not only to develop high-performance multimodal probes for more accurate and reliable diagnosis, but also to understand the fate of these probes in vivo. In this context, a novel PEGylated Dy-doped NaGdF4 nanoprobe (PEG-NaGdF4:Dy) was designed and fabricated as a T1/T2-weighted MRI/CT imaging agent. This nanoprobe has a distinct longitudinal relaxivity (r1 = 5.17 mM-1 s-1), relatively high transverse relaxivity (r2 = 10.64 mM-1 s-1), and exhibits strong X-ray attenuation properties (44.70 HU L g-1) in vitro. Furthermore, T1/T2-weighted MRI/CT imaging in vivo confirmed that this PEG-NaGdF4:Dy nanoprobe could lead to a significant contrast enhancement effect on liver, spleen and kidney at 24 h post injection. The MTT assay, histological analysis, and biodistribution investigation demonstrated that this multifunctional nanoprobe possessed relatively low cytotoxicity, negligible tissue damage and could be completely excreted out of the body of mice as time prolonged. Therefore, the present PEG-NaGdF4:Dy nanoprobe has the potential for the development of multifunctional T1/T2-weighted MRI/CT imaging to provide more comprehensive and accurate diagnosis information.Lanthanide-based multimodal probes with high sensitivity, simple synthesis strategy, and good biocompatibility promise new applications for clinical diagnosis. However, today's challenge is not only to develop high-performance multimodal probes for more accurate and reliable diagnosis, but also to understand the fate of these probes in vivo. In this context, a novel PEGylated Dy-doped NaGdF4 nanoprobe (PEG-NaGdF4:Dy) was designed and fabricated as a T1/T2-weighted MRI/CT imaging agent. This nanoprobe has a distinct longitudinal relaxivity (r1 = 5.17 mM-1 s-1), relatively high transverse relaxivity (r2 = 10.64 mM-1 s-1), and

  13. Mirror Metrology Using Nano-Probe Supports

    NASA Technical Reports Server (NTRS)

    Robinson, David; Hong, Maoling; Byron, Glenn; McClelland, Ryan; Chan, Kai-Wing

    2012-01-01

    stabilize the mirror for measurement, nano-probes support the mirror, causing the mirror to be over-constrained.

  14. 3D Image Processing of Two-Photon Microscopy Images Depicting Nanoprobes in Skin

    NASA Astrophysics Data System (ADS)

    Bongo, Andrew E.

    Choosing a deconvolution algorithm can be beneficial when imaging nanoprobes in skin by means of two-photon microscopy. By design, deconvolution algorithms can increase the signal to noise ratio of the raw images and thus make it easier to identify discrete, subresolution nanoprobes from blurry two-photon image data. This poses the favorable benefit of knowing more precise locations of nanoprobes inside skin. This thesis demonstrates how the Expectation-Maximization deconvolution algorithm (EM algorithm) can be applied to three-dimensional, two-photon images depicting quantum dot nanoprobes inside human skin. This was accomplished in part by devising a way to deliver nanoprobes inside skin by means of low frequency ultrasound. Many nanoprobes become sparsely scattered inside skin when using this nanoprobe delivery methodology. The scattered nanoprobes resulting from the nanoprobe delivery pose a unique benefit in acquiring an experimental point spread function of the imaging system. This in turn gives an accurate representation of the point spread function that can be used as an input to the EM algorithm. The methodology of utilizing the EM algorithm in this manner is presented.

  15. Horseradish peroxidase and aptamer dual-functionalized nanoprobe for the amplification detection of alpha-methylacyl-CoA racemase.

    PubMed

    Zeng, Yongyi; Zheng, Aixian; Wu, Jing; Cai, Zhixiong; Huang, Aimin; Liu, Xiaolong

    2015-10-29

    Alpha-methylacyl-CoA racemase (AMACR) is over-expressed in many cancer types and can serve as a novel diagnostic biomarker. Development of convenient and sensitive detection methods of AMACR is of particular importance for cancer diagnosis. Aptamers are a type of recognition elements, which possess many advantages over antibody, making them suitable for applications in biosensing and biotechnology. In this work, we use the efficient surface modification of gold nanoparticles (AuNPs) to prepare the horseradish peroxidase (HRP) and aptamer dual-functionalized nanoprobe. The immobilization of HRP and thiol-terminated aptamer on the surface of AuNPs can be achieved through electrostatic interaction and the formation of Au-S bond, respectively. This nanoprobe, which is used as discriminating and catalytic probe, can be combined with enzyme immunoassay method to increase the detection sensitivity of AMACR. The detection limit can reach as low as 4.6 pg mL(-1) due to the dual signal amplification from enzymatic cycling and the high loading of enzymes on AuNPs. This sensitivity is about three orders of magnitude higher than that of AMACR aptamer based fluorescence method, which is also comparable to or one order of magnitude higher than that of ELISA. Furthermore, this method is more simple and effective, which not only avoids the conjugation between recognition element and the catalytic enzyme, but also achieves greater signal amplification. This assay could be used as a sensitive and selective platform for the detection of target protein. PMID:26547498

  16. Andreev nanoprobe of half-metallic CrO2 films using superconducting cuprate tips

    NASA Astrophysics Data System (ADS)

    Turel, C. S.; Guilaran, I. J.; Xiong, P.; Wei, J. Y. T.

    2011-11-01

    Superconducting tips of YBa2Cu3O7-x were used to perform point-contact Andreev reflection spectroscopy on half-metallic CrO2 thin films. At 4.2 K, strong suppression of the d-wave Andreev reflection characteristics was observed, consistent with the high spin polarization of CrO2. Our technique was validated by comparison with data taken on non-magnetic Au films and with data taken by superconducting Pb tips. The point contacts were estimated to be ≲10 nm in size, attesting to their ballistic and microscopic nature. Our results demonstrate the feasibility of using superconducting cuprate tips as spin-sensitive nanoprobes of ferromagnets.

  17. Achieving Vibration Stability of the NSLS-II Hard X-ray Nanoprobe Beamline

    SciTech Connect

    Simos, N.; Chu, Y. N.; Broadbent, A.; Nazaretski, E.; Margulies, L.; Dyling, O.; Shen, Q.; Fallier, M.

    2010-08-30

    The Hard X-ray Nanoprobe (HXN) Beamline of National Synchrotron Light Source II (NSLS-lI) requires high levels of stability in order to achieve the desired instrument resolution. To ensure that the design of the endstation helps meet the stringent criteria and that natural and cultural vibration is mitigated both passively and actively, a comprehensive study complimentary to the design process has been undertaken. Vibration sources that have the potential to disrupt sensitive experiments such as wind, traffic and NSLS II operating systems have been studied using state of the art simulations and an array of field data. Further, final stage vibration isolation principles have been explored in order to be utilized in supporting endstation instruments. This paper presents results of the various study aspects and their influence on the HXN design optimization.

  18. Electrochemical nanoprobes for the chemical detection of neurotransmitters

    PubMed Central

    Colombo, Michelle L.

    2015-01-01

    Neurotransmitters, acting as chemical messengers, play an important role in neurotransmission, which governs many functional aspects of nervous system activity. Electrochemical probes have proven a very useful technique to study neurotransmission, especially to quantify and qualify neurotransmitters. With the emerging interests in probing neurotransmission at the level of single cells, single vesicles, as well as single synapses, probes that enable detection of neurotransmitters at the nanometer scale become vitally important. Electrochemical nanoprobes have been successfully employed in nanometer spatial resolution imaging of single nanopores of Si membrane and single Au nanoparticles, providing both topographical and chemical information, thus holding great promise for nanometer spatial study of neurotransmission. Here we present the current state of electrochemical nanoprobes for chemical detection of neurotransmitters, focusing on two types of nanoelectrodes, i.e. carbon nanoelectrode and nano-ITIES pipet electrode. PMID:26327927

  19. Targeting Negative Surface Charges of Cancer Cells by Multifunctional Nanoprobes.

    PubMed

    Chen, Bingdi; Le, Wenjun; Wang, Yilong; Li, Zhuoquan; Wang, Dong; Ren, Lei; Lin, Ling; Cui, Shaobin; Hu, Jennifer J; Hu, Yihui; Yang, Pengyuan; Ewing, Rodney C; Shi, Donglu; Cui, Zheng

    2016-01-01

    A set of electrostatically charged, fluorescent, and superparamagnetic nanoprobes was developed for targeting cancer cells without using any molecular biomarkers. The surface electrostatic properties of the established cancer cell lines and primary normal cells were characterized by using these nanoprobes with various electrostatic signs and amplitudes. All twenty two randomly selected cancer cell lines of different organs, but not normal control cells, bound specifically to the positively charged nanoprobes. The relative surface charges of cancer cells could be quantified by the percentage of cells captured magnetically. The activities of glucose metabolism had a profound impact on the surface charge level of cancer cells. The data indicate that an elevated glycolysis in the cancer cells led to a higher level secretion of lactate. The secreted lactate anions are known to remove the positive ions, leaving behind the negative changes on the cell surfaces. This unique metabolic behavior is responsible for generating negative cancer surface charges in a perpetuating fashion. The metabolically active cancer cells are shown to a unique surface electrostatic pattern that can be used for recovering cancer cells from the circulating blood and other solutions. PMID:27570558

  20. Targeting Negative Surface Charges of Cancer Cells by Multifunctional Nanoprobes

    PubMed Central

    Chen, Bingdi; Le, Wenjun; Wang, Yilong; Li, Zhuoquan; Wang, Dong; Ren, Lei; Lin, Ling; Cui, Shaobin; Hu, Jennifer J.; Hu, Yihui; Yang, Pengyuan; Ewing, Rodney C.; Shi, Donglu; Cui, Zheng

    2016-01-01

    A set of electrostatically charged, fluorescent, and superparamagnetic nanoprobes was developed for targeting cancer cells without using any molecular biomarkers. The surface electrostatic properties of the established cancer cell lines and primary normal cells were characterized by using these nanoprobes with various electrostatic signs and amplitudes. All twenty two randomly selected cancer cell lines of different organs, but not normal control cells, bound specifically to the positively charged nanoprobes. The relative surface charges of cancer cells could be quantified by the percentage of cells captured magnetically. The activities of glucose metabolism had a profound impact on the surface charge level of cancer cells. The data indicate that an elevated glycolysis in the cancer cells led to a higher level secretion of lactate. The secreted lactate anions are known to remove the positive ions, leaving behind the negative changes on the cell surfaces. This unique metabolic behavior is responsible for generating negative cancer surface charges in a perpetuating fashion. The metabolically active cancer cells are shown to a unique surface electrostatic pattern that can be used for recovering cancer cells from the circulating blood and other solutions. PMID:27570558

  1. MRI nanoprobes based on chemical exchange saturation transfer: LnIII chelates anchored on the surface of mesoporous silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Ferrauto, Giuseppe; Carniato, Fabio; Tei, Lorenzo; Hu, He; Aime, Silvio; Botta, Mauro

    2014-07-01

    The formation of ternary complexes between neutral LnIII-DO3A chelates anchored on MCM-41 mesoporous silica nanoparticles (MSNs) and silanol groups on the surface allows obtaining highly efficient chemical exchange saturation transfer (CEST) MRI nanoprobes. These new probes achieve excellent sensitivity in the μM range (per LnIII ion), significantly greater than that of other paramagnetic CEST nanosystems such as dendrimers or micelles and three orders of magnitude higher than that of the corresponding molecular agents.The formation of ternary complexes between neutral LnIII-DO3A chelates anchored on MCM-41 mesoporous silica nanoparticles (MSNs) and silanol groups on the surface allows obtaining highly efficient chemical exchange saturation transfer (CEST) MRI nanoprobes. These new probes achieve excellent sensitivity in the μM range (per LnIII ion), significantly greater than that of other paramagnetic CEST nanosystems such as dendrimers or micelles and three orders of magnitude higher than that of the corresponding molecular agents. Electronic supplementary information (ESI) available: Synthesis and characterization of the materials; Z- and ST-spectra of all materials; sensitivity threshold for TmDO3A-MCM-41 and EuDO3A-MCM-41 pH and temperature dependence of ST% for TbDO3A-MCM-41. See DOI: 10.1039/c4nr02753a

  2. Parameter estimation using a complete signal and inspiral templates for low-mass binary black holes with Advanced LIGO sensitivity

    NASA Astrophysics Data System (ADS)

    Cho, Hee-Suk

    2015-12-01

    We study the validity of inspiral templates in gravitational wave data analysis with Advanced LIGO sensitivity for low mass binary black holes with total masses of M≤slant 30{M}⊙ . We mainly focus on the nonspinning system. As our complete inspiral-merger-ringdown waveform model ({I}{M}{R} ), we assume the phenomenological model, ‘PhenomA’, and define our inspiral template model ({{I}}{{merg}}) by taking the inspiral part into account from {I}{M}{R} up to the merger frequency ({f}{{merg}}). We first calculate the true statistical uncertainties using {I}{M}{R} signals and {I}{M}{R} templates. Next, using {I}{M}{R} signals and {{I}}{{merg}} templates, we calculate fitting factors and systematic biases, and compare the biases with the true statistical uncertainties. We find that the valid criteria of the bank of {{I}}{{merg}} templates are obtained as {M}{{crit}}˜ 24{M}⊙ for detection (if M\\gt {M}{{crit}}, the fitting factor is smaller than 0.97), and {M}{{crit}}˜ 26{M}⊙ for parameter estimation (if M\\gt {M}{{crit}}, the systematic bias is larger than the true statistical uncertainty where the signal-to-noise ratio is 20), respectively. In order to see the dependence on the cutoff frequency of the inspiral waveforms, we define another inspiral model {{I}}{{isco}} which is terminated at the innermost-stable-circular-orbit frequency ({f}{{isco}}\\lt {f}{{merg}}). We find that the valid criteria of the bank of {{I}}{{isco}} templates are obtained as {M}{{crit}}˜ 15{M}⊙ and ˜ 17{M}⊙ for detection and parameter estimation, respectively. We investigate the statistical uncertainties for the inspiral template models considering various signal-to-noise ratios, and compare those to the true statistical uncertainties. We also consider the aligned-spinning system with fixed mass ratio ({m}1/{m}2=3) and spin (χ =0.5) by employing the recent phenomenological model, ‘PhenomC’. In this case, we find that the true statistical uncertainties can be much larger

  3. Fabrication of SERS-fluorescence dual modal nanoprobes and application to multiplex cancer cell imaging

    NASA Astrophysics Data System (ADS)

    Lee, Sangyeop; Chon, Hyangah; Yoon, Soo-Young; Lee, Eun Kyu; Chang, Soo-Ik; Lim, Dong Woo; Choo, Jaebum

    2011-12-01

    We report a highly sensitive optical imaging technology using surface-enhanced Raman scattering (SERS)-fluorescence dual modal nanoprobes (DMNPs). Fluorescence microscopy is a well-known imaging technique that shows specific protein distributions within cells. However, most currently available fluorescent organic dyes have relatively weak emission intensities and are rapidly photo-bleached. Thus more sensitive and stable probes are needed. In this work we develop DMNPs, which can be used for both SERS and fluorescence detection. SERS detection is a powerful technique that allows ultrasensitive chemical or biochemical analysis through unlimited multiplexing and single molecule sensitivity. Combining advantages of fluorescence and SERS allows these dual modal nanostructures to be used as powerful probes for novel biomedical imaging. In this work, the fabrication and characterization of the SERS-fluorescence DMNPs and application to biological imaging were investigated using markers CD24 and CD44, which are co-expressed in MDA-MB-231 breast cancer cells, as a model system. SERS imaging with DMNPs was found to be a powerful tool to determine the co-localization of CD24 and CD44 in the cell.We report a highly sensitive optical imaging technology using surface-enhanced Raman scattering (SERS)-fluorescence dual modal nanoprobes (DMNPs). Fluorescence microscopy is a well-known imaging technique that shows specific protein distributions within cells. However, most currently available fluorescent organic dyes have relatively weak emission intensities and are rapidly photo-bleached. Thus more sensitive and stable probes are needed. In this work we develop DMNPs, which can be used for both SERS and fluorescence detection. SERS detection is a powerful technique that allows ultrasensitive chemical or biochemical analysis through unlimited multiplexing and single molecule sensitivity. Combining advantages of fluorescence and SERS allows these dual modal nanostructures to be used

  4. A higher performance dye-sensitized solar cell based on the modified PMII/EMIMBF4 binary room temperature ionic liquid electrolyte

    NASA Astrophysics Data System (ADS)

    Wang, Wu-yang; Cao, Da-peng; Wang, Chao; Zhang, Xiang-yu; Mi, Bao-xiu; Gao, Zhi-qiang; Liang, Zhong-cheng

    2016-07-01

    Additives and iodine (I2) are used to modify the binary room temperature ionic liquid (RTIL) electrolyte to enhance the photovoltaic performance of dye-sensitized solar cells (DSSCs). The short-circuit current density ( J SC) of 17.89 mA/cm2, open circuit voltage ( V OC) of 0.71 V and fill factor ( FF) of 0.50 are achieved in the optimal device. An average photoelectric conversion efficiency ( PCE) of 6.35% is achieved by optimization, which is over two times larger than that of the parent device before optimization (2.06%), while the maximum PCE can reach up to 6.63%.

  5. Preparation and characterization of nontoxic magnetic-luminescent nanoprobe

    NASA Astrophysics Data System (ADS)

    Yin, Nai-Qiang; Liu, Ling; Lei, Jie-Mei; Liu, Yan-Song; Gong, Mao-Gang; Wu, Yi-Zhi; Zhu, Li-Xin; Xu, Xiao-Liang

    2012-11-01

    A novel nontoxic, magnetic, and luminescent nanoprobe is prepared by using complex nanoparticles, which are composed of Fe3O4 nanoparticles and Mn-doped ZnS quantum dots (QDs). The nanocomposite probe can provide visible optical and magnetic resonance images simultaneously. Compared with the previously toxic cadmium and mercury based QDs, the superiority of the Mn-doped ZnS QDs is little virulence. The structure and the properties of the particles are characterized by energy dispersive X-ray analysis spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, photoluminescence spectroscopy, and vibrating sample magnetometer.

  6. High-resolution fluorescence mapping of impurities in historical zinc oxide pigments: hard X-ray nanoprobe applications to the paints of Pablo Picasso

    NASA Astrophysics Data System (ADS)

    Casadio, Francesca; Rose, Volker

    2013-04-01

    Here for the first time we describe the use of high resolution nanoprobe X-ray fluorescence (XRF) mapping for the analysis of artists' paints, hierarchically complex materials typically composed of binder, pigments, fillers, and other additives. The work undertaken at the nanoprobe sought to obtain highly spatially resolved, highly sensitive mapping of metal impurities (Pb, Cd, Fe, and other metals) in submicron particles of zinc oxide pigments used in early 20th century artists' tube paints and enamel paints, with particular emphasis on Ripolin, a popular brand of French house paint used extensively by Pablo Picasso and some of his contemporaries. Analysis revealed that the Zn oxide particles only contain a little Fe, proving that the highest quality Zn oxide pigment, free of Pb and Cd, was used for Ripolin house paints as well as artists' paints. Nanoprobe XRF mapping also demonstrated that artists' tube paints generally have more abundant fillers and additional whites (based on Pb, Ti, Ca) than Ripolin paints, which contain mostly pure zinc oxide. The chemical characterization of paints at the nanoscale opens the path to a better understanding of their fabrication and chemical reactivity.

  7. Nanoprobe-Enhanced, Split Aptamer-Based Electrochemical Sandwich Assay for Ultrasensitive Detection of Small Molecules.

    PubMed

    Zhao, Tao; Liu, Ran; Ding, Xiaofan; Zhao, Juncai; Yu, Haixiang; Wang, Lei; Xu, Qing; Wang, Xuan; Lou, Xinhui; He, Miao; Xiao, Yi

    2015-08-01

    It is quite challenging to improve the binding affinity of antismall molecule aptamers. We report that the binding affinity of anticocaine split aptamer pairs improved by up to 66-fold by gold nanoparticles (AuNP)-attached aptamers due to the substantially increased local concentration of aptamers and multiple and simultaneous ligand interactions. The significantly improved binding affinity enables the detection of small molecule targets with unprecedented sensitivity, as demonstrated in nanoprobe-enhanced split aptamer-based electrochemical sandwich assays (NE-SAESA). NE-SAESA replaces the traditional molecular reporter probe with AuNPs conjugated to multiple reporter probes. The increased binding affinity allowed us to use 1,000-fold lower reporter probe concentrations relative to those employed in SAESA. We show that the near-elimination of background in NE-SAESA effectively improves assay sensitivity by ∼1,000-100,000-fold for ATP and cocaine detection, relative to equivalent SAESA. With the ongoing development of new strategies for the selection of aptamers, we anticipate that our sensor platform should offer a generalizable approach for the high-sensitivity detection of diverse targets. More importantly, we believe that NE-SAESA represents a novel strategy to improve the binding affinity between a small molecule and its aptamer and potentially can be extended to other detection platforms. PMID:26171721

  8. Solid-phase single molecule biosensing using dual-color colocalization of fluorescent quantum dot nanoprobes

    NASA Astrophysics Data System (ADS)

    Liu, Jianbo; Yang, Xiaohai; Wang, Kemin; Wang, Qing; Liu, Wei; Wang, Dong

    2013-10-01

    The development of solid-phase surface-based single molecule imaging technology has attracted significant interest during the past decades. Here we demonstrate a sandwich hybridization method for highly sensitive detection of a single thrombin protein at a solid-phase surface based on the use of dual-color colocalization of fluorescent quantum dot (QD) nanoprobes. Green QD560-modified thrombin binding aptamer I (QD560-TBA I) were deposited on a positive poly(l-lysine) assembled layer, followed by bovine serum albumin blocking. It allowed the thrombin protein to mediate the binding of the easily detectable red QD650-modified thrombin binding aptamer II (QD650-TBA II) to the QD560-TBA I substrate. Thus, the presence of the target thrombin can be determined based on fluorescent colocalization measurements of the nanoassemblies, without target amplification or probe separation. The detection limit of this assay reached 0.8 pM. This fluorescent colocalization assay has enabled single molecule recognition in a separation-free detection format, and can serve as a sensitive biosensing platform that greatly suppresses the nonspecific adsorption false-positive signal. This method can be extended to other areas such as multiplexed immunoassay, single cell analysis, and real time biomolecule interaction studies.The development of solid-phase surface-based single molecule imaging technology has attracted significant interest during the past decades. Here we demonstrate a sandwich hybridization method for highly sensitive detection of a single thrombin protein at a solid-phase surface based on the use of dual-color colocalization of fluorescent quantum dot (QD) nanoprobes. Green QD560-modified thrombin binding aptamer I (QD560-TBA I) were deposited on a positive poly(l-lysine) assembled layer, followed by bovine serum albumin blocking. It allowed the thrombin protein to mediate the binding of the easily detectable red QD650-modified thrombin binding aptamer II (QD650-TBA II) to

  9. Directly interrogating single quantum dot labelled UvrA2 molecules on DNA tightropes using an optically trapped nanoprobe

    PubMed Central

    Simons, Michelle; Pollard, Mark R.; Hughes, Craig D.; Ward, Andrew D.; Van Houten, Bennett; Towrie, Mike; Botchway, Stan W.; Parker, Anthony W.; Kad, Neil M.

    2015-01-01

    In this study we describe a new methodology to physically probe individual complexes formed between proteins and DNA. By combining nanoscale, high speed physical force measurement with sensitive fluorescence imaging we investigate the complex formed between the prokaryotic DNA repair protein UvrA2 and DNA. This approach uses a triangular, optically-trapped “nanoprobe” with a nanometer scale tip protruding from one vertex. By scanning this tip along a single DNA strand suspended between surface-bound micron-scale beads, quantum-dot tagged UvrA2 molecules bound to these ‘”DNA tightropes” can be mechanically interrogated. Encounters with UvrA2 led to deflections of the whole nanoprobe structure, which were converted to resistive force. A force histogram from all 144 detected interactions generated a bimodal distribution centered on 2.6 and 8.1 pN, possibly reflecting the asymmetry of UvrA2’s binding to DNA. These observations successfully demonstrate the use of a highly controllable purpose-designed and built synthetic nanoprobe combined with fluorescence imaging to study protein-DNA interactions at the single molecule level. PMID:26691010

  10. Photostimulable Near-Infrared Persistent Luminescent Nanoprobes for Ultrasensitive and Longitudinal Deep-Tissue Bio-Imaging

    PubMed Central

    Chuang, Yen-Jun; Zhen, Zipeng; Zhang, Fan; Liu, Feng; Mishra, Jyoti P.; Tang, Wei; Chen, Hongmin; Huang, Xinglu; Wang, Lianchun; Chen, Xiaoyuan; Xie, Jin; Pan, Zhengwei

    2014-01-01

    In vivo fluorescence imaging suffers from suboptimal signal-to-noise ratio and shallow detection depth, which is caused by the strong tissue autofluorescence under constant external excitation and the scattering and absorption of short-wavelength light in tissues. Here we address these limitations by using a novel type of optical nanoprobes, photostimulable LiGa5O8:Cr3+ near-infrared (NIR) persistent luminescence nanoparticles, which, with very-long-lasting NIR persistent luminescence and unique photo-stimulated persistent luminescence (PSPL) capability, allow optical imaging to be performed in an excitation-free and hence, autofluorescence-free manner. LiGa5O8:Cr3+ nanoparticles pre-charged by ultraviolet light can be repeatedly (>20 times) stimulated in vivo, even in deep tissues, by short-illumination (~15 seconds) with a white light-emitting-diode flashlight, giving rise to multiple NIR PSPL that expands the tracking window from several hours to more than 10 days. Our studies reveal promising potential of these nanoprobes in cell tracking and tumor targeting, exhibiting exceptional sensitivity and penetration that far exceed those afforded by conventional fluorescence imaging. PMID:25285164

  11. Photostimulable near-infrared persistent luminescent nanoprobes for ultrasensitive and longitudinal deep-tissue bio-imaging.

    PubMed

    Chuang, Yen-Jun; Zhen, Zipeng; Zhang, Fan; Liu, Feng; Mishra, Jyoti P; Tang, Wei; Chen, Hongmin; Huang, Xinglu; Wang, Lianchun; Chen, Xiaoyuan; Xie, Jin; Pan, Zhengwei

    2014-01-01

    In vivo fluorescence imaging suffers from suboptimal signal-to-noise ratio and shallow detection depth, which is caused by the strong tissue autofluorescence under constant external excitation and the scattering and absorption of short-wavelength light in tissues. Here we address these limitations by using a novel type of optical nanoprobes, photostimulable LiGa5O8:Cr(3+) near-infrared (NIR) persistent luminescence nanoparticles, which, with very-long-lasting NIR persistent luminescence and unique photo-stimulated persistent luminescence (PSPL) capability, allow optical imaging to be performed in an excitation-free and hence, autofluorescence-free manner. LiGa5O8:Cr(3+) nanoparticles pre-charged by ultraviolet light can be repeatedly (>20 times) stimulated in vivo, even in deep tissues, by short-illumination (~15 seconds) with a white light-emitting-diode flashlight, giving rise to multiple NIR PSPL that expands the tracking window from several hours to more than 10 days. Our studies reveal promising potential of these nanoprobes in cell tracking and tumor targeting, exhibiting exceptional sensitivity and penetration that far exceed those afforded by conventional fluorescence imaging. PMID:25285164

  12. EGFR-specific nanoprobe biodistribution in mouse models

    NASA Astrophysics Data System (ADS)

    Fashir, Samia A.; Castilho, Maiara L.; Hupman, Michael A.; Lee, Christopher L. D.; Raniero, Leandro J.; Alwayn, Ian; Hewitt, Kevin C.

    2015-06-01

    Nanotechnology offers a targeted approach to both imaging and treatment of cancer, the leading cause of death worldwide. Previous studies have found nanoparticles with a wide variety of coatings initiate an immune response leading to sequestration in the liver and spleen. In an effort to find a nanoparticle platform which does not elicit an immune response we created 43/44 nm gold or silver nanoparticles coated with biomolecules normally produced by the body, α-lipoic acid and the Epidermal Growth Factor (EGF), and have used mass spectroscopy to determine their biodistribution in mouse models, 24 hours following tail vein injection. Relative to controls, mouse EGF (mEGF) coated silver and gold nanoprobes are found at reduced levels in the liver and spleen. mEGF coated gold nanoprobes on the other hand do not appear to elicit any immune response, as they are found at background levels in these organs. As a result they should remain in circulation for longer and accumulate at high levels in tumors by the enhanced permeability retention (EPR) effect.

  13. Multifunctional hydrogel nano-probes for atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Lee, Jae Seol; Song, Jungki; Kim, Seong Oh; Kim, Seokbeom; Lee, Wooju; Jackman, Joshua A.; Kim, Dongchoul; Cho, Nam-Joon; Lee, Jungchul

    2016-05-01

    Since the invention of the atomic force microscope (AFM) three decades ago, there have been numerous advances in its measurement capabilities. Curiously, throughout these developments, the fundamental nature of the force-sensing probe--the key actuating element--has remained largely unchanged. It is produced by long-established microfabrication etching strategies and typically composed of silicon-based materials. Here, we report a new class of photopolymerizable hydrogel nano-probes that are produced by bottom-up fabrication with compressible replica moulding. The hydrogel probes demonstrate excellent capabilities for AFM imaging and force measurement applications while enabling programmable, multifunctional capabilities based on compositionally adjustable mechanical properties and facile encapsulation of various nanomaterials. Taken together, the simple, fast and affordable manufacturing route and multifunctional capabilities of hydrogel AFM nano-probes highlight the potential of soft matter mechanical transducers in nanotechnology applications. The fabrication scheme can also be readily utilized to prepare hydrogel cantilevers, including in parallel arrays, for nanomechanical sensor devices.

  14. Multifunctional hydrogel nano-probes for atomic force microscopy

    PubMed Central

    Lee, Jae Seol; Song, Jungki; Kim, Seong Oh; Kim, Seokbeom; Lee, Wooju; Jackman, Joshua A.; Kim, Dongchoul; Cho, Nam-Joon; Lee, Jungchul

    2016-01-01

    Since the invention of the atomic force microscope (AFM) three decades ago, there have been numerous advances in its measurement capabilities. Curiously, throughout these developments, the fundamental nature of the force-sensing probe—the key actuating element—has remained largely unchanged. It is produced by long-established microfabrication etching strategies and typically composed of silicon-based materials. Here, we report a new class of photopolymerizable hydrogel nano-probes that are produced by bottom-up fabrication with compressible replica moulding. The hydrogel probes demonstrate excellent capabilities for AFM imaging and force measurement applications while enabling programmable, multifunctional capabilities based on compositionally adjustable mechanical properties and facile encapsulation of various nanomaterials. Taken together, the simple, fast and affordable manufacturing route and multifunctional capabilities of hydrogel AFM nano-probes highlight the potential of soft matter mechanical transducers in nanotechnology applications. The fabrication scheme can also be readily utilized to prepare hydrogel cantilevers, including in parallel arrays, for nanomechanical sensor devices. PMID:27199165

  15. Multifunctional hydrogel nano-probes for atomic force microscopy.

    PubMed

    Lee, Jae Seol; Song, Jungki; Kim, Seong Oh; Kim, Seokbeom; Lee, Wooju; Jackman, Joshua A; Kim, Dongchoul; Cho, Nam-Joon; Lee, Jungchul

    2016-01-01

    Since the invention of the atomic force microscope (AFM) three decades ago, there have been numerous advances in its measurement capabilities. Curiously, throughout these developments, the fundamental nature of the force-sensing probe-the key actuating element-has remained largely unchanged. It is produced by long-established microfabrication etching strategies and typically composed of silicon-based materials. Here, we report a new class of photopolymerizable hydrogel nano-probes that are produced by bottom-up fabrication with compressible replica moulding. The hydrogel probes demonstrate excellent capabilities for AFM imaging and force measurement applications while enabling programmable, multifunctional capabilities based on compositionally adjustable mechanical properties and facile encapsulation of various nanomaterials. Taken together, the simple, fast and affordable manufacturing route and multifunctional capabilities of hydrogel AFM nano-probes highlight the potential of soft matter mechanical transducers in nanotechnology applications. The fabrication scheme can also be readily utilized to prepare hydrogel cantilevers, including in parallel arrays, for nanomechanical sensor devices. PMID:27199165

  16. First principle study of the sensitivity of CO adsorption on pure and binary clusters of lead and silicon

    NASA Astrophysics Data System (ADS)

    Narayan Samanta, Pabitra; Das, Kalyan Kumar

    2014-07-01

    The interactions of a CO molecule with pure and binary clusters of Pb and Si up to five atoms are theoretically investigated. The lowest-energy isomers of metal cluster carbonyl complexes are obtained by global optimization of the potential energy hypersurface using Monte Carlo simulation coupled with simulated annealing followed by pseudopotential based plane wave density functional theory (DFT) calculations, and then by local optimization using hybrid DFT calculations at the B3LYP/ aug-cc-pVTZ-pp level of theory. The CO binding energies and Gibbs free energy changes (ΔG) are computed to determine the kinetic and thermodynamic stability of the metal cluster-CO complexes. The variations of adsorption energy, HOMO-LUMO energy gap, and NBO charge on the CO fragment with the size of the metal clusters are reported. The linear correlations among different parameters such as C-O bond elongation, changes in the C-O stretching frequency, and NBO charge on CO are established to confirm the CO adsorption on various pure and binary clusters of Pb and Si. Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2014-40750-2

  17. Rational design of a bisphenol A aptamer selective surface-enhanced Raman scattering nanoprobe.

    PubMed

    Marks, Haley L; Pishko, Michael V; Jackson, George W; Coté, Gerard L

    2014-12-01

    Surface-enhanced Raman scattering (SERS) optical nanoprobes offer a number of advantages for ultrasensitive analyte detection. These functionalized colloidal nanoparticles are a multifunctional assay component. providing a platform for conjugation to spectral tags, stabilizing polymers, and biorecognition elements such as aptamers or antibodies. We demonstrate the design and characterization of a SERS-active nanoprobe and investigate the nanoparticles' biorecognition capabilities for use in a competitive binding assay. Specifically, the nanoprobe is designed for the quantification of bisphenol A (BPA) levels in the blood after human exposure to the toxin in food and beverage plastic packaging. The nanoprobes demonstrated specific affinity to a BPA aptamer with a dissociation constant Kd of 54 nM, and provided a dose-dependent SERS spectra with a limit of detection of 3 nM. Our conjugation approach shows the versatility of colloidal nanoparticles in assay development, acting as detectable spectral tagging elements and biologically active ligands concurrently. PMID:25329684

  18. Rational Design of a Bisphenol A Aptamer Selective Surface-Enhanced Raman Scattering Nanoprobe

    PubMed Central

    2015-01-01

    Surface-enhanced Raman scattering (SERS) optical nanoprobes offer a number of advantages for ultrasensitive analyte detection. These functionalized colloidal nanoparticles are a multifunctional assay component. providing a platform for conjugation to spectral tags, stabilizing polymers, and biorecognition elements such as aptamers or antibodies. We demonstrate the design and characterization of a SERS-active nanoprobe and investigate the nanoparticles’ biorecognition capabilities for use in a competitive binding assay. Specifically, the nanoprobe is designed for the quantification of bisphenol A (BPA) levels in the blood after human exposure to the toxin in food and beverage plastic packaging. The nanoprobes demonstrated specific affinity to a BPA aptamer with a dissociation constant Kd of 54 nM, and provided a dose-dependent SERS spectra with a limit of detection of 3 nM. Our conjugation approach shows the versatility of colloidal nanoparticles in assay development, acting as detectable spectral tagging elements and biologically active ligands concurrently. PMID:25329684

  19. Fluorescent and Bioluminescent Nanoprobes for In Vitro and In Vivo Detection of Matrix Metalloproteinase Activity.

    PubMed

    Lee, Hawon; Kim, Young-Pil

    2015-06-01

    Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that degrade the extracellular matrix (ECM) and regulate the extracellular microenvironment. Despite the significant role that MMP activity plays in cell-cell and cell-ECM interactions, migration, and differentiation, analyses of MMPs in vitro and in vivo have relied upon their abundance using conventional immunoassays, rather than their enzymatic activities. To resolve this issue, diverse nanoprobes have emerged and proven useful as effective activity-based detection tools. Here, we review the recent advances in luminescent nanoprobes and their applications in in vitro diagnosis and in vivo imaging of MMP activity. Nanoprobes with the purpose of sensing MMP activity consist of recognition and detection units, which include MMP-specific substrates and luminescent (fluorescent or bioluminescent) nanoparticles, respectively. With further research into improvement of the optical performance, it is anticipated that luminescent nanoprobes will have great potential for the study of the functional roles of proteases in cancer biology and nanomedicine. PMID:25817215

  20. Dextran-coated gold nanoprobes for the concentration and detection of protein biomarkers.

    PubMed

    Chiu, Ricky Y T; Nguyen, Phuong T; Wang, Juntian; Jue, Erik; Wu, Benjamin M; Kamei, Daniel T

    2014-11-01

    The lateral-flow immunoassay (LFA) is a well-established point-of-care detection assay that is rapid, inexpensive, easy to use, and portable. However, its sensitivity is lower than that of traditional lab-based assays. Previously, we improved the sensitivity of LFA by concentrating the target biomolecules using aqueous two-phase systems (ATPSs) prior to their detection. In this study, we report the first-ever utilization of dextran-coated gold nanoprobes (DGNPs) as the colorimetric indicator for LFA. In addition, the DGNPs are the key component in our pre-concentration process, where they remain stable and functional in the high salt environment of our ATPS solution, capture the target protein with conjugated antibodies, and allow the rapid concentration of the target protein in our ATPS for use in the subsequent LFA detection step. By combining this pre-concentration step with LFA, the detection limit of LFA for a model protein was improved by 10-fold. We further improved our ATPS from previous studies by enabling phase separation at room temperature in 30 min. By using DGNPs for the concentration and detection of protein biomarkers in the sequential combination of the ATPS and LFA steps, we move closer to developing an effective protein detection assay which uses no power or lab-based equipment. PMID:24874602

  1. Mobile based gold nanoprobe TB diagnostics for point-of-need.

    PubMed

    Veigas, B; Fortunato, E; Baptista, P V

    2015-01-01

    Nanotechnology based diagnostics has provided improved tools for pathogen detection and sensitive and specific characterization of antibiotic resistance signatures. Tuberculosis (TB) is caused by members of the Mycobacterium tuberculosis Complex (MTBC) and, according to the World Health Organization, is one of the most serious infectious diseases in the world. Recent advances in molecular diagnostics of TB have improved both the detection time and sensitivity but they still require specialized technical personnel and cumbersome laboratory equipment. Diagnostics at point-of-need is crucial to TB control as it may provide rapid identification of pathogen together with the resistance profile of TB strains, originated from single nucleotide polymorphisms (SNPs) in different loci, allowing for a more accurate indication of the adequate therapy.Gold nanoparticles have been widely used in molecular diagnostics platforms. Here, we describe the use of gold nanoprobes (oligonucleotide functionalized gold nanoparticles) to be used in a non-cross-linking colorimetric method for the direct detection of specific DNA targets. Due to the remarkable optical properties of gold nanoparticles, this detection system provides colorimetric detection of the pathogen together with the potential of identification of several single nucleotide polymorphisms (SNPs) involved in TB resistance to antibiotics. For point-of-need use, we adapted this strategy to a low-cost mobile scheme using a paper based revelation platform and where the spectral signature is transposed to RGB data via a smartphone device. This way, identification of pathogen and characterization of resistance signatures is achieved at point-of-need. PMID:25626530

  2. Nanotubes as nanoprobes in scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Dai, Hongjie; Hafner, Jason H.; Rinzler, Andrew G.; Colbert, Daniel T.; Smalley, Richard E.

    1996-11-01

    SINCE the invention of the scanning tunnelling microscope1, the value of establishing a physical connection between the macroscopic world and individual nanometre-scale objects has become increasingly evident, both for probing these objects2-4 and for direct manipulation5-7 and fabrication8-10 at the nanometre scale. While good progress has been made in controlling the position of the macroscopic probe of such devices to sub-ångström accuracy, and in designing sensitive detection schemes, less has been done to improve the probe tip itself4. Ideally the tip should be as precisely defined as the object under investigation, and should maintain its integrity after repeated use not only in high vacuum but also in air and water. The best tips currently used for scanning probe microscopy do sometimes achieve sub-nanometre resolution, but they seldom survive a 'tip crash' with the surface, and it is rarely clear what the atomic configuration of the tip is during imaging. Here we show that carbon nanotubes11,12 might constitute well defined tips for scanning probe microscopy. We have attached individual nanotubes several micrometres in length to the silicon cantilevers of conventional atomic force microscopes. Because of their flexibility, the tips are resistant to damage from tip crashes, while their slenderness permits imaging of sharp recesses in surface topography. We have also been able to exploit the electrical conductivity of nanotubes by using them for scanning tunnelling microscopy.

  3. Multiplex detection of breast cancer biomarkers using plasmonic molecular sentinel nanoprobes

    NASA Astrophysics Data System (ADS)

    Wang, Hsin-Neng; Vo-Dinh, Tuan

    2009-02-01

    We have demonstrated for the first time the feasibility of multiplex detection using the surface-enhanced Raman scattering-based molecular sentinel (MS) technology in a homogeneous solution. Two MS nanoprobes tagged with different Raman labels were used to detect the presence of the erbB-2 and ki-67 breast cancer biomarkers. The multiplexing capability of the MS technique was demonstrated by mixing the two MS nanoprobes and tested in the presence of single or multiple DNA targets.

  4. A Prodrug-type, MMP-2-targeting Nanoprobe for Tumor Detection and Imaging

    PubMed Central

    Wang, Yaping; Lin, Tingting; Zhang, Wenyuan; Jiang, Yifan; Jin, Hongyue; He, Huining; Yang, Victor C.; Chen, Yi; Huang, Yongzhuo

    2015-01-01

    Tumor-associated proteases (TAPs) have been intensively studied because of their critical roles in cancer development. As a case in point, expression of matrix metalloproteases (MMP) is significantly up-regulated in tumorigenesis, invasion, and metastasis among a majority of cancers. Here we present a prodrug-type, MMP-2-responsive nanoprobe system with high efficiency and low toxicity for detecting MMP-2-overexpressed tumors. The nanoprobe system is featured by its self-assembled fabrication and FRET effect. This prodrug-type nanoprobe is selectively activated by MMP-2, and thus useful for detection of the MMP-2-overexpressed cells and tumors. The nanoprobe system works successfully in various animal tumor models, including human fibrosarcoma and subcutaneous glioma xenograft. Furthermore, in order to overcome the blood brain barrier (BBB) and achieve brain tumor targeting, a transferrin-receptor targeting peptide (T7 peptide) is strategically incorporated into the nanoprobe. The T7-functionalized nanoprobe is capable of detecting the orthotopic brain tumor, with clear, real-time in vivo imaging. This method is promising for in vivo detection of brain tumor, and real-time monitor of a TAP (i.e., MMP-2). PMID:26000052

  5. A Novel Nanoprobe for Multimodal Imaging Is Effectively Incorporated into Human Melanoma Metastatic Cell Lines

    PubMed Central

    Aasen, Synnøve Nymark; Pospisilova, Aneta; Eichler, Tilo Wolf; Panek, Jiri; Hruby, Martin; Stepanek, Petr; Spriet, Endy; Jirak, Daniel; Skaftnesmo, Kai Ove; Thorsen, Frits

    2015-01-01

    To facilitate efficient drug delivery to tumor tissue, several nanomaterials have been designed, with combined diagnostic and therapeutic properties. In this work, we carried out fundamental in vitro and in vivo experiments to assess the labeling efficacy of our novel theranostic nanoprobe, consisting of glycogen conjugated with a red fluorescent probe and gadolinium. Microscopy and resazurin viability assays were used to study cell labeling and cell viability in human metastatic melanoma cell lines. Fluorescence lifetime correlation spectroscopy (FLCS) was done to investigate nanoprobe stability. Magnetic resonance imaging (MRI) was performed to study T1 relaxivity in vitro, and contrast enhancement in a subcutaneous in vivo tumor model. Efficient cell labeling was demonstrated, while cell viability, cell migration, and cell growth was not affected. FLCS showed that the nanoprobe did not degrade in blood plasma. MRI demonstrated that down to 750 cells/μL of labeled cells in agar phantoms could be detected. In vivo MRI showed that contrast enhancement in tumors was comparable between Omniscan contrast agent and the nanoprobe. In conclusion, we demonstrate for the first time that a non-toxic glycogen-based nanoprobe may effectively visualize tumor cells and tissue, and, in future experiments, we will investigate its therapeutic potential by conjugating therapeutic compounds to the nanoprobe. PMID:26370983

  6. Biomolecular environment, quantification, and intracellular interaction of multifunctional magnetic SERS nanoprobes.

    PubMed

    Büchner, Tina; Drescher, Daniela; Merk, Virginia; Traub, Heike; Guttmann, Peter; Werner, Stephan; Jakubowski, Norbert; Schneider, Gerd; Kneipp, Janina

    2016-08-15

    Multifunctional composite nanoprobes consisting of iron oxide nanoparticles linked to silver and gold nanoparticles, Ag-Magnetite and Au-Magnetite, respectively, were introduced by endocytic uptake into cultured fibroblast cells. The cells containing the non-toxic nanoprobes were shown to be displaceable in an external magnetic field and can be manipulated in microfluidic channels. The distribution of the composite nanostructures that are contained in the endosomal system is discussed on the basis of surface-enhanced Raman scattering (SERS) mapping, quantitative laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) micromapping, and cryo soft X-ray tomography (cryo soft-XRT). Cryo soft-XRT of intact, vitrified cells reveals that the composite nanoprobes form intra-endosomal aggregates. The nanoprobes provide SERS signals from the biomolecular composition of their surface in the endosomal environment. The SERS data indicate the high stability of the nanoprobes and of their plasmonic properties in the harsh environment of endosomes and lysosomes. The spectra point at the molecular composition at the surface of the Ag-Magnetite and Au-Magnetite nanostructures that is very similar to that of other composite structures, but different from the composition of pure silver and gold SERS nanoprobes used for intracellular investigations. As shown by the LA-ICP-MS data, the uptake efficiency of the magnetite composites is approximately two to three times higher than that of the pure gold and silver nanoparticles. PMID:27353290

  7. Zooming in on a sleeping giant: milliarcsecond High Sensitivity Array imaging of the black hole binary V404 Cyg in quiescence

    NASA Astrophysics Data System (ADS)

    Miller-Jones, J. C. A.; Gallo, E.; Rupen, M. P.; Mioduszewski, A. J.; Brisken, W.; Fender, R. P.; Jonker, P. G.; Maccarone, T. J.

    2008-08-01

    Observations of the black hole X-ray binary V404 Cyg with the very long baseline interferometer the High Sensitivity Array (HSA) have detected the source at a frequency of 8.4GHz, providing a source position accurate to 0.3mas relative to the calibrator source. The observations put an upper limit of 1.3mas on the source size (5.2au at 4kpc) and a lower limit of 7 × 106 K on its brightness temperature during the normal quiescent state, implying that the radio emission must be non-thermal, most probably synchrotron radiation, possibly from a jet. The radio light curves show a short flare, with a rise time of ~30min, confirming that the source remains active in the quiescent state.

  8. FITC-quencher based caspase 3-activatable nanoprobes for effectively sensing caspase 3 in vitro and in cells

    NASA Astrophysics Data System (ADS)

    Tang, Anming; Mei, Bin; Wang, Weijuan; Hu, Wanglai; Li, Fang; Zhou, Jun; Yang, Qing; Cui, Hua; Wu, Mian; Liang, Gaolin

    2013-09-01

    By employing fluorescence resonance energy transfer (FRET) quenching, we rationally designed two new FITC-quencher based nanoprobes for effectively sensing caspase 3 (Casp3) in vitro and in cells. Our nanoprobes hold promise for assessing the chemotherapeutic effect of cancer treatment.By employing fluorescence resonance energy transfer (FRET) quenching, we rationally designed two new FITC-quencher based nanoprobes for effectively sensing caspase 3 (Casp3) in vitro and in cells. Our nanoprobes hold promise for assessing the chemotherapeutic effect of cancer treatment. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03339b

  9. Nonlinear nanoprobes for characterizing ultrafast optical near field

    NASA Astrophysics Data System (ADS)

    Li, Haifeng

    With the rapid development of ultrafast optics and nanophotonics, it is crucial to measure the spatiotemporal evolution of an ultrafast optical near field in nanometer spatial and femtosecond temporal resolution with minimal perturbation. Although near-field scanning optical microscopy (NSOM) can achieve nanoscale spatial resolution and various ultrashort pulse diagnostic tools can characterize femtosecond laser pulses, yet such capability to noninvasively characterize the nanoscale characteristics of femtosecond pulses in all three spatial dimensions remains elusive. In this dissertation, we developed different types of nonlinear optical probes to characterize ultrashort optical pulses. The nonlinear optical probe is composed of three parts, a silica fiber taper, a single nanowire bonded to the end of the fiber and nonlinear nanoparticles attached on the tip of the nanowire. The optical fiber taper can be readily mounted on a mechanical stage and served as a macroscopic interface for handling and positioning control. The single nanowire bridges the dimension gap between the nanocrystals and the fiber taper, and is critical for achieving large aspect ratio and hence minimizing optical scattering and perturbation. The nonlinear nanoparticles give rise to its capability to characterize ultrashort optical pulses. The unique fusion of nanoscale and nonlinear features in developed nonlinear optical probes provides the ability of probing ultrafast optical field in complex 3D microand nano- structures. The demonstration of such ability is crucial for understanding the interaction of ultrafast optical fields and nanoscale systems. The fabrication processes of the nonlinear optical probes are illustrated in detail and the optical properties of the probes are investigated. Two different types of nonlinear optical probes, two-photon fluorescent nanoprobes and Second HARmonic nanoProbes (SHARP), are fabricated. Interferometric autocorrelation measurements near the focal point

  10. Preparation and Characterization of Bimodal Magnetofluorescent Nanoprobes for Biomedical Application

    NASA Astrophysics Data System (ADS)

    Lei, Jie-Mei; Xu, Xiao-Liang; Liu, Ling; Yin, Nai-Qiang; Zhu, Li-Xin

    2012-09-01

    Magnetic-fluorescent bifunctional Fe3O4/SiO2-CdTeS nanocomposites are synthesized. Fe3O4 superparamagnetic nanoparticles are firstly prepared through the thermal decomposition of Fe oleate precursors and coated with a mesoporous silica shell using the Stöber method, and the silica surface is then modified with positively charged amino groups by adding 3-aminopropyltrimethoxysilane. Finally, negatively charged CdTeS quantum dots are linked and assembled onto the positively charged surface of Fe3O4/SiO2 through electrostatic interactions. X-ray diffraction, transmission electron microscopy, photoluminescence spectroscopy, and magnetometry are applied to characterize the nanocomposites. The results show that the bifunctional nanocomposites combine the optical properties of near-infrared CdTeS quantum dots with the superparamagnetic properties of Fe3O4 perfectly, expressing the potential application as a biocompatible magnetofuorescent nanoprobe for in vivo labelling.

  11. Quantum Dot-Based Nanoprobes for In Vivo Targeted Imaging

    PubMed Central

    Zhu, Yian; Hong, Hao; Xu, Zhi Ping; Li, Zhen; Cai, Weibo

    2013-01-01

    Fluorescent semiconductor quantum dots (QDs) have attracted tremendous attention over the last decade. The superior optical properties of QDs over conventional organic dyes make them attractive labels for a wide variety of biomedical applications, whereas their potential toxicity and instability in biological environment has puzzled scientific researchers. Much research effort has been devoted to surface modification and functionalization of QDs to make them versatile probes for biomedical applications, and significant progress has been made over the last several years. This review article aims to describe the current state-of-the-art of the synthesis, modification, bioconjugation, and applications of QDs for in vivo targeted imaging. In addition, QD-based multifunctional nanoprobes are also summarized. PMID:24206136

  12. PEG-Like Nanoprobes: Multimodal, Pharmacokinetically and Optically Tunable Nanomaterials

    PubMed Central

    Guo, Yanyan; Yuan, Hushan; Claudio, Natalie M.; Kura, Sreekanth; Shakerdge, Naomi; Mempel, Thorsten R.; Bacskai, Brian J.; Josephson, Lee

    2014-01-01

    “PEG-like Nanoprobes” (PN’s) are pharmacokinetically and optically tunable nanomaterials whose disposition in biological systems can be determined by fluorescence or radioactivity. PN’s feature a unique design where a single PEG polymer surrounds a short fluorochrome and radiometal bearing peptide, and endows the resulting nanoprobe with pharmacokinetic control (based on molecular weight of the PEG selected) and optical tunability (based on the fluorochrome selected), while the chelate provides a radiolabeling option. PN’s were used to image brain capillary angiography (intravital 2-photon microscopy), tumor capillary permeability (intravital fluorescent microscopy), and the tumor enhanced permeability and retention (EPR) effect (111In-PN and SPECT). Clinical applications of PN’s include use as long blood half-life fluorochromes for intraoperative angiography, for measurements of capillary permeability in breast cancer lesions, and to image EPR by SPECT, for stratifying patient candidates for long-circulating nanomedicines that may utilize the EPR mechanism. PMID:24781778

  13. Quantum dot-based nanoprobes for in vivo targeted imaging.

    PubMed

    Zhu, Y; Hong, H; Xu, Z P; Li, Z; Cai, W

    2013-12-01

    Fluorescent semiconductor quantum dots (QDs) have attracted tremendous attention over the last decade. The superior optical properties of QDs over conventional organic dyes make them attractive labels for a wide variety of biomedical applications, whereas their potential toxicity and instability in biological environment have puzzled scientific researchers. Much research effort has been devoted to surface modification and functionalization of QDs to make them versatile probes for biomedical applications, and significant progress has been made over the last several years. This review article aims to describe the current state-of-the-art of the synthesis, modification, bioconjugation, and applications of QDs for in vivo targeted imaging. In addition, QD-based multifunctional nanoprobes are also summarized. PMID:24206136

  14. Ultrasensitive Detection of Ebola Virus Oligonucleotide Based on Upconversion Nanoprobe/Nanoporous Membrane System.

    PubMed

    Tsang, Ming-Kiu; Ye, WeiWei; Wang, Guojing; Li, Jingming; Yang, Mo; Hao, Jianhua

    2016-01-26

    Ebola outbreaks are currently of great concern, and therefore, development of effective diagnosis methods is urgently needed. The key for lethal virus detection is high sensitivity, since early-stage detection of virus may increase the probability of survival. Here, we propose a luminescence scheme of assay consisting of BaGdF5:Yb/Er upconversion nanoparticles (UCNPs) conjugated with oligonucleotide probe and gold nanoparticles (AuNPs) linked with target Ebola virus oligonucleotide. As a proof of concept, a homogeneous assay was fabricated and tested, yielding a detection limit at picomolar level. The luminescence resonance energy transfer is ascribed to the spectral overlapping of upconversion luminescence and the absorption characteristics of AuNPs. Moreover, we anchored the UCNPs and AuNPs on a nanoporous alumina (NAAO) membrane to form a heterogeneous assay. Importantly, the detection limit was greatly improved, exhibiting a remarkable value at the femtomolar level. The enhancement is attributed to the increased light-matter interaction throughout the nanopore walls of the NAAO membrane. The specificity test suggested that the nanoprobes were specific to Ebola virus oligonucleotides. The strategy combining UCNPs, AuNPs, and NAAO membrane provides new insight into low-cost, rapid, and ultrasensitive detection of different diseases. Furthermore, we explored the feasibility of clinical application by using inactivated Ebola virus samples. The detection results showed great potential of our heterogeneous design for practical application. PMID:26720408

  15. Design of Metalloporphyrin-Based Dendritic Nanoprobes for Two-Photon Microscopy of Oxygen

    PubMed Central

    Lebedev, Artem Y.; Troxler, Thomas; Vinogradov, Sergei A.

    2009-01-01

    Metalloporphyrin-based phosphorescent nanoprobes are being developed for two-photon microscopy of oxygen. In these molecular constructs generation of porphyrin triplet states upon two-photon excitation is induced upon the intramolecular Förster-type resonance energy transfer from a covalently attached 2P antenna. In the earlier developed prototypes, electron transfer between the antenna and the metalloporphyrin strongly interfered with the phosphorescence, reducing the sensitivity and the dynamic range of the sensors. By tuning the distances between the antenna and the core and adjusting their redox potentials the unwanted electron transfer could be prevented. An array of phosphorescent Pt porphyrins (energy transfer acceptors) and 2P dyes (energy transfer donors) was screened using dynamic quenching of phosphorescence, and the FRET-pair with the minimal ET rate was identified. This pair, consisting of Coumarin-343 and Pt meso-tetra-(4-alkoxyphenyl)porphyrin, was used to construct a probe in which the antenna fragments were linked to the termini of G3 poly(arylglycine) (AG) dendrimer with PtP core. The folded dendrimer formed an insulating layer between the porphyrin and the antenna, simultaneously controlling the rate of oxygen quenching (Stern-Volmer oxygen quenching constant). Modification of the dendrimer periphery with oligoethyleneglycol residues made the probe’s signal insensitive to the presence of proteins and other macromolecular solutes. PMID:19763243

  16. The Bionanoprobe: hard X-ray fluorescence nanoprobe with cryogenic capabilities

    PubMed Central

    Chen, S.; Deng, J.; Yuan, Y.; Flachenecker, C.; Mak, R.; Hornberger, B.; Jin, Q.; Shu, D.; Lai, B.; Maser, J.; Roehrig, C.; Paunesku, T.; Gleber, S. C.; Vine, D. J.; Finney, L.; VonOsinski, J.; Bolbat, M.; Spink, I.; Chen, Z.; Steele, J.; Trapp, D.; Irwin, J.; Feser, M.; Snyder, E.; Brister, K.; Jacobsen, C.; Woloschak, G.; Vogt, S.

    2014-01-01

    Hard X-ray fluorescence microscopy is one of the most sensitive techniques for performing trace elemental analysis of biological samples such as whole cells and tissues. Conventional sample preparation methods usually involve dehydration, which removes cellular water and may consequently cause structural collapse, or invasive processes such as embedding. Radiation-induced artifacts may also become an issue, particularly as the spatial resolution increases beyond the sub-micrometer scale. To allow imaging under hydrated conditions, close to the ‘natural state’, as well as to reduce structural radiation damage, the Bionanoprobe (BNP) has been developed, a hard X-ray fluorescence nanoprobe with cryogenic sample environment and cryo transfer capabilities, dedicated to studying trace elements in frozen-hydrated biological systems. The BNP is installed at an undulator beamline at sector 21 of the Advanced Photon Source. It provides a spatial resolution of 30 nm for two-dimensional fluorescence imaging. In this first demonstration the instrument design and motion control principles are described, the instrument performance is quantified, and the first results obtained with the BNP on frozen-hydrated whole cells are reported. PMID:24365918

  17. Tunneling of redox enzymes to design nano-probes for monitoring NAD(+) dependent bio-catalytic activity.

    PubMed

    Akshath, Uchangi Satyaprasad; Bhatt, Praveena

    2016-11-15

    Monitoring of bio-catalytic events by using nano-probes is of immense interest due to unique optical properties of metal nanoparticles. In the present study, tunneling of enzyme activity was achieved using redox cofactors namely oxidized cytochrome-c (Cyt-c) and Co-enzyme-Q (Co-Q) immobilized on Quantum dots (QDs) which acted as a bio-probe for NAD(+) dependent dehydrogenase catalyzed reaction. We studied how electron transfer from substrate to non-native electron acceptors can differentially modify photoluminescence properties of CdTe QDs. Two probes were designed, QD-Ox-Cyt-c and QD-Ox-Co-Q, which were found to quench the fluorescence of QDs. However, formaldehyde dehydrogenase (FDH) catalyzed reduction of Cyt-c and Co-Q on the surface of QDs lead to fluorescence turn-on of CdTe QDs. This phenomenon was successfully used for the detection of HCHO in the range of 0.01-100,000ng/mL (LOD of 0.01ng/mL) using both QD-Ox-Cyt-c (R(2)=0.93) and QD-Ox-Co-Q (R(2)=0.96). Further probe performance and stability in samples like milk, wine and fruit juice matrix were studied and we could detect HCHO in range of 0.001-100,000ng/mL (LOD of 0.001ng/mL) with good stability and sensitivity of probe in real samples (R(2)=0.97). Appreciable recovery and detection sensitivity in the presence of metal ions suggests that the developed nano-probes can be used successfully for monitoring dehydrogenase based bio-catalytic events even in the absence of NAD(+). Proposed method is advantageous over classical methods as clean up/ derivatization of samples is not required for formaldehyde detection. PMID:27179565

  18. Optimized dendrimer-encapsulated gold nanoparticles and enhanced carbon nanotube nanoprobes for amplified electrochemical immunoassay of E. coli in dairy product based on enzymatically induced deposition of polyaniline.

    PubMed

    Zhang, Xinai; Shen, Jianzhong; Ma, Haile; Jiang, Yuxiang; Huang, Chenyong; Han, En; Yao, Boshui; He, Yunyao

    2016-06-15

    A highly sensitive immunosensor was reported for Escherichia coli assay in dairy product based on electrochemical measurement of polyaniline (PAn) that was catalytically deposited by horseradish peroxidase (HRP) labels. Herein, the immunosensor was developed by using poly(amidoamine) dendrimer-encapsulated gold nanoparticles (PAMAM(Au)) as sensing platform. Importantly, the optimal HAuCl4/PAMAM ratio was investigated to design the efficient PAMAM(Au) nanocomposites. The nanocomposites were proven to not only increase the amount of immobilized capture antibody (cAb), but also accelerate the electron transfer process. Moreover, the {dAb-CNT-HRP} nanoprobes were prepared by exploiting the amplification effect of multiwalled carbon nanotubes (CNTs) for loading detection antibody (dAb) and enormous HRP labels. After a sandwich immunoreaction, the quantitatively captured nanoprobes could catalyze oxidation aniline to produce electroactive PAn for electrochemical measurement. On the basis of signal amplification of the PAMAM(Au)-based immunosensor and the {dAb-CNT-HRP} nanoprobes, the proposed strategy exhibited a linear relationship between the peak current of PAn and the logarithmic value of E. coli concentration ranging from 1.0 × 10(2) to 1.0 × 10(6) cfu mL(-1) with a detection limit of 50 cfu mL(-1) (S/N=3), and the electrochemical detection of E. coli could be achieved in 3h. The electrochemical immunosensor was also used to determine E. coli in dairy product (pure fresh milk, infant milk powder, yogurt in shelf-life and expired yogurt), and the recoveries of standard additions were in the range of 96.8-108.7%. Overall, this method gave a useful protocol for E. coli assay with high sensitivity, acceptable accuracy and satisfying stability, and thus provided a powerful tool to estimate the quality of dairy product. PMID:26908184

  19. SERS-fluorescence joint spectral encoded magnetic nanoprobes for multiplex cancer cell separation.

    PubMed

    Wang, Zhuyuan; Zong, Shenfei; Chen, Hui; Wang, Chunlei; Xu, Shuhong; Cui, Yiping

    2014-11-01

    A new kind of cancer cell separation method is demonstrated, using surface-enhanced Raman scattering (SERS) and fluorescence dual-encoded magnetic nanoprobes. The designed nanoprobes can realize SERS-fluorescence joint spectral encoding (SFJSE) and greatly improve the multiplexing ability. The nanoprobes have four main components, that is, the magnetic core, SERS generator, fluorescent agent, and targeting antibody. These components are assembled with a multi-layered structure to form the nanoprobes. Specifically, silica-coated magnetic nanobeads (MBs) are used as the inner core. Au core-Ag shell nanorods (Au@Ag NRs) are employed as the SERS generators and attached on the silica-coated MBs. After burying these Au@Ag NRs with another silica layer, CdTe quantum dots (QDs), that is, the fluorescent agent, are anchored onto the silica layer. Finally, antibodies are covalently linked to CdTe QDs. SFJSE is fulfilled by using different Raman molecules and QDs with different emission wavelengths. By utilizing four human cancer cell lines and one normal cell line as the model cells, the nanoprobes can specifically and simultaneously separate target cancer cells from the normal ones. This SFJSE-based method greatly facilitates the multiplex, rapid, and accurate cancer cell separation, and has a prosperous potential in high-throughput analysis and cancer diagnosis. PMID:24862088

  20. In vivo MRI detection of gliomas by chlorotoxin-conjugated superparamagnetic nanoprobes.

    PubMed

    Sun, Conroy; Veiseh, Omid; Gunn, Jonathan; Fang, Chen; Hansen, Stacey; Lee, Donghoon; Sze, Raymond; Ellenbogen, Richard G; Olson, Jim; Zhang, Miqin

    2008-03-01

    Converging advances in the development of nanoparticle-based imaging probes and improved understanding of the molecular biology of brain tumors offer the potential to provide physicians with new tools for the diagnosis and treatment of these deadly diseases. However, the effectiveness of promising nanoparticle technologies is currently limited by insufficient accumulation of these contrast agents within tumors. Here a biocompatible nanoprobe composed of a poly(ethylene glycol) (PEG) coated iron oxide nanoparticle that is capable of specifically targeting glioma tumors via the surface-bound targeting peptide, chlorotoxin (CTX), is presented. The preferential accumulation of the nanoprobe within gliomas and subsequent magnetic resonance imaging (MRI) contrast enhancement are demonstrated in vitro in 9L cells and in vivo in tumors of a xenograft mouse model. TEM imaging reveals that the nanoprobes are internalized into the cytoplasm of 9L cells and histological analysis of selected tissues indicates that there are no acute toxic effects of these nanoprobes. High targeting specificity and benign biological response establish this nanoprobe as a potential platform to aid in the diagnosis and treatment of gliomas and other tumors of neuroectodermal origin. PMID:18232053

  1. An efficient core-shell fluorescent silica nanoprobe for ratiometric fluorescence detection of pH in living cells.

    PubMed

    Fu, Jingni; Ding, Changqin; Zhu, Anwei; Tian, Yang

    2016-08-01

    Intracellular pH plays a vital role in cell biology, including signal transduction, ion transport and homeostasis. Herein, a ratiometric fluorescent silica probe was developed to detect intracellular pH values. The pH sensitive dye fluorescein isothiocyanate isomer I (FITC), emitting green fluorescence, was hybridized with reference dye rhodamine B (RB), emitting red fluorescence, as a dual-emission fluorophore, in which RB was embedded in a silica core of ∼40 nm diameter. Moreover, to prevent fluorescence resonance energy transfer between FITC and RB, FITC was grafted onto the surface of core-shell silica colloidal particles with a shell thickness of 10-12 nm. The nanoprobe exhibited dual emission bands centered at 517 and 570 nm, under single wavelength excitation of 488 nm. RB encapsulated in silica was inert to pH change and only served as reference signals for providing built-in correction to avoid environmental effects. Moreover, FITC (λem = 517 nm) showed high selectivity toward H(+) against metal ions and amino acids, leading to fluorescence variation upon pH change. Consequently, variations of the two fluorescence intensities (Fgreen/Fred) resulted in a ratiometric pH fluorescent sensor. The specific nanoprobe showed good linearity with pH variation in the range of 6.0-7.8. It can be noted that the fluorescent silica probe demonstrated good water dispersibility, high stability and low cytotoxicity. Accordingly, imaging and biosensing of pH variation was successfully achieved in HeLa cells. PMID:27291898

  2. Work-function measurement by high-resolution scanning Kelvin nanoprobe

    NASA Astrophysics Data System (ADS)

    Cheran, Larisa-Emilia; Johnstone, Sherri; Sadeghi, Saman; Thompson, Michael

    2007-03-01

    Nanoscience promises to transform today's world in the same way that integrated semiconductor devices transformed the world of electronics and computation. In the post-genomic era, the greatest challenge is to make connections between the structures and functions of biomolecules at the nanometre-scale level in order to underpin the understanding of larger scale systems in the fields of human biology and physiology. To achieve this, instruments with new capabilities need to be researched and developed, with particular emphasis on new levels of sensitivity, precision and resolution for biomolecular analysis. This paper describes an instrument able to analyse structures that range from tenths of a nanometre (proteins, DNA) to micron-scale structures (living cells), which can be investigated non-destructively in their normal state and subsequently in chemical- or biochemical-modified conditions. The high-resolution scanning Kelvin nanoprobe (SKN) measures the work-function changes at molecular level, instigated by local charge reconfiguration due to translational motion of mobile charges, dipolar relaxation of bound charges, interfacial polarization and structural and conformational modifications. In addition to detecting surface electrical properties, the instrument offers, in parallel, the surface topographic image, with nanometre resolution. The instrument can also be used to investigate subtle work function/topography variations which occur in, for example, corrosion, contamination, adsorption and desorption of molecules, crystallographic studies, mechanical stress studies, surface photovoltaic studies, material science, biocompatibility studies, microelectronic characterization in semiconductor technology, oxide and thin films, surface processing and treatments, surfaces and interfaces characterization. This paper presents the design and development of the instrument, the basic principles of the method and the challenges involved to achieve nanometric resolution

  3. Bioorthogonal SERS Nanoprobes for Mulitplex Spectroscopic Detection, Tumor Cell Targeting, and Tissue Imaging.

    PubMed

    Wu, Junzhou; Liang, Duanwei; Jin, Qingqing; Liu, Jie; Zheng, Meiling; Duan, Xuanming; Tang, Xinjing

    2015-09-01

    A surface-enhanced Raman scattering (SERS) technique shows extraordinary features for a range of biological and biomedical applications. Herein, a series of novel bioorthogonal SERS nanoprobes were constructed with Gold nanoflower (AuNF) and Raman reporters, the signals of which were located in a Raman-silent region of biological samples. AS1411 aptamer was also co-conjugated with AuNF through a self-assembled monolayer coverage strategy. Multiplex SERS imaging using these nanoprobes with three different bioorthogonal small-molecule Raman reporters is successfully achieved with high multiplexing capacity in a biologically Raman-silent region. These Raman nanoprobes co-conjugated with AS1411 showed high affinity for tumor cells with overexpressed nucleolin and can be used for selective tumor cell screening and tissue imaging. PMID:26222682

  4. Moving graphene devices from lab to market: advanced graphene-coated nanoprobes.

    PubMed

    Hui, Fei; Vajha, Pujashree; Shi, Yuanyuan; Ji, Yanfeng; Duan, Huiling; Padovani, Andrea; Larcher, Luca; Li, Xiao Rong; Xu, Jing Juan; Lanza, Mario

    2016-04-28

    After more than a decade working with graphene there is still a preoccupying lack of commercial devices based on this wonder material. Here we report the use of high-quality solution-processed graphene sheets to fabricate ultra-sharp probes with superior performance. Nanoprobes are versatile tools used in many fields of science, but they can wear fast after some experiments, reducing the quality and increasing the cost of the research. As the market of nanoprobes is huge, providing a solution for this problem should be a priority for the nanotechnology industry. Our graphene-coated nanoprobes not only show enhanced lifetime, but also additional unique properties of graphene, such as hydrophobicity. Moreover, we have functionalized the surface of graphene to provide piezoelectric capability, and have fabricated a nano relay. The simplicity and low cost of this method, which can be used to coat any kind of sharp tip, make it suitable for the industry, allowing production on demand. PMID:26593053

  5. A smart fluorescence nanoprobe for the detection of cellular alkaline phosphatase activity and early osteogenic differentiation.

    PubMed

    Cao, Feng-Yi; Fan, Jin-Xuan; Long, Yue; Zeng, Xuan; Zhang, Xian-Zheng

    2016-07-01

    In the past decades, biomaterials were designed to induce stem cell toward osteogenic differentiation. However, conventional methods for evaluation osteogenic differentiation all required a process of cell fixation or lysis, which induce waste of a large number of cells. In this study, a fluorescence nanoprobe was synthesized by combining phosphorylated fluoresceinamine isomer I (FLA) on the surface of mesoporous silica-coated superparamagnetic iron oxide (Fe3O4@mSiO2) nanoparticles. In the presence of alkaline phosphatase (ALP), the phosphorylated FLA on the nanoprobe would be hydrolyzed, resulting in a fluorescence recovery of FLA. During early osteogenic differentiation, a high-level expression of cellular ALP was induced, which accelerated the hydrolysis of phosphorylated FLA, resulting in an enhancement of cellular fluorescence intensity. This fluorescence nanoprobe provides us a rapid and non-toxic method for the detection of cellular ALP activity and early osteogenic differentiation. PMID:26961462

  6. Graphene oxide-encoded Ag nanoshells with single-particle detection sensitivity towards cancer cell imaging based on SERRS.

    PubMed

    Yim, DaBin; Kang, Homan; Jeon, Su-Ji; Kim, Hye-In; Yang, Jin-Kyoung; Kang, Tae Wook; Lee, Sangyeop; Choo, Jaebum; Lee, Yoon-Sik; Kim, Jin Woong; Kim, Jong-Ho

    2015-05-21

    Developing ultrasensitive Raman nanoprobes is one of the emerging interests in the field of biosensing and bioimaging. Herein, we constructed a new type of surface-enhanced resonance Raman scattering nanoprobe composed of an Ag nanoshell as a surface-enhanced Raman scattering-active nanostructure, which was encapsulated with 4,7,10-trioxa-1,13-tridecanediamine-functionalized graphene oxide as an ultrasensitive Raman reporter exhibiting strong resonance Raman scattering including distinct D and G modes. The designed nanoprobe was able to produce much more intense and simpler Raman signals even at a single particle level than the Ag nanoshell bearing a well-known Raman reporter, which is beneficial for the sensitive detection of a target in a complex biological system. Finally, this ultrasensitive nanoprobe successfully demonstrated its potential for bioimaging of cancer cells using Raman spectroscopy. PMID:25811703

  7. ZnO light-emitting nanoprobes for tumor detection

    NASA Astrophysics Data System (ADS)

    Chen, Yung-Tsan; Shen, Yi-Chun; Yang, Sheng-Chieh; Yang, Tsung-Lin; Huang, Jian-Jang

    2013-02-01

    Tumor detection is a significant health issue, but it is still a limit to identify cancer cells during tumor resection by using traditional methods such as fluorescence. In this study, zinc oxide (ZnO) nanorods bonded to antibodies was investigated as nanoprobes for sensing cancer cells. The result shows that antibodies toward epidermal growth factor receptor (EGFR) can be connected to ZnO nanorods and EGFR receptors of squamous cell carcinoma (SCC). The cancer cells can be recognized via the observation of purple light emission from these probes by using naked eye or an optical microscope. By contrast, the HS68 cells with less EGFR expression had no purple light emission as the probes were washed off. Besides, from the photoluminescent spectra, the intensity ratio between the purple light (from ZnO nanorods) and green band (from the autofluorescence of cells) is much higher in SCC than in HS68 cells, which suggest that the cancer cells can be detected by comparing the peak intensity ratio. The probes have the potential clinical application for real-time tumor detection, and the cancer cells can be excised more precisely with the help of purple light emission.

  8. Efficiency enhancement in dye sensitized solar cells using gel polymer electrolytes based on a tetrahexylammonium iodide and MgI2 binary iodide system.

    PubMed

    Bandara, T M W J; Dissanayake, M A K L; Jayasundara, W J M J S R; Albinsson, I; Mellander, B-E

    2012-06-28

    Quasi-solid-state dye-sensitized solar cells have drawn the attention of scientists and technologists as a potential candidate to supplement future energy needs. The conduction of iodide ions in quasi-solid-state polymer electrolytes and the performance of dye sensitized solar cells containing such electrolytes can be enhanced by incorporating iodides having appropriate cations. Gel-type electrolytes, based on PAN host polymers and mixture of salts tetrahexylammonium iodide (Hex4N(+)I(-)) and MgI2, were prepared by incorporating ethylene carbonate and propylene carbonate as plasticizers. The salt composition in the binary mixture was varied in order to optimize the performance of solar cells. The electrolyte containing 120% Hex4N(+)I(-) with respect to weight of PAN and without MgI2 showed the highest conductivity out of the compositions studied, 2.5 × 10(-3) S cm(-1) at 25 °C, and a glass transition at -102.4 °C. However, the electrolyte containing 100% Hex4N(+)I(-) and 20% MgI2 showed the best solar cell performance highlighting the influence of the cation on the performance of the cell. The predominantly ionic behaviour of the electrolytes was established from the dc polarization data and all the electrolytes exhibit iodide ion transport. Seven different solar cells were fabricated employing different electrolyte compositions. The best cell using the electrolyte with 100% Hex4N(+)I(-) and 20% MgI2 with respect to PAN weight showed 3.5% energy conversion efficiency and 8.6 mA cm(-2) short circuit current density. PMID:22618351

  9. Tumor Vascular Permeability to a Nanoprobe Correlates to Tumor-Specific Expression Levels of Angiogenic Markers

    PubMed Central

    Karathanasis, Efstathios; Chan, Leslie; Karumbaiah, Lohitash; McNeeley, Kathleen; D'Orsi, Carl J.; Annapragada, Ananth V.; Sechopoulos, Ioannis; Bellamkonda, Ravi V.

    2009-01-01

    Background Vascular endothelial growth factor (VEGF) receptor-2 is the major mediator of the mitogenic, angiogenic, and vascular hyperpermeability effects of VEGF on breast tumors. Overexpression of VEGF and VEGF receptor-2 is associated with the degree of pathomorphosis of the tumor tissue and unfavorable prognosis. In this study, we demonstrate that non-invasive quantification of the degree of tumor vascular permeability to a nanoprobe correlates with the VEGF and its receptor levels and tumor growth. Methodology/Principal Findings We designed an imaging nanoprobe and a methodology to detect the intratumoral deposition of a 100 nm-scale nanoprobe using mammography allowing measurement of the tumor vascular permeability in a rat MAT B III breast tumor model. The tumor vascular permeability varied widely among the animals. Notably, the VEGF and VEGF receptor-2 gene expression of the tumors as measured by qRT-PCR displayed a strong correlation to the imaging-based measurements of vascular permeability to the 100 nm-scale nanoprobe. This is in good agreement with the fact that tumors with high angiogenic activity are expected to have more permeable blood vessels resulting in high intratumoral deposition of a nanoscale agent. In addition, we show that higher intratumoral deposition of the nanoprobe as imaged with mammography correlated to a faster tumor growth rate. This data suggest that vascular permeability scales to the tumor growth and that tumor vascular permeability can be a measure of underlying VEGF and VEGF receptor-2 expression in individual tumors. Conclusions/Significance This is the first demonstration, to our knowledge, that quantitative imaging of tumor vascular permeability to a nanoprobe represents a form of a surrogate, functional biomarker of underlying molecular markers of angiogenesis. PMID:19513111

  10. Recent patents on imaging nanoprobes for brain tumor diagnosis and therapy.

    PubMed

    Qi, Lifeng; Zheng, Shu; Lin, Biaoyang

    2010-06-01

    Multifunctional nanoprobes, such as nanocrystals, nanoshells, and luminescent nanomaterials, have been developed for imaging biological processes; such as cell signaling, neuroimaging, protein conformation probing, DNA conformation probing, gene transcription, virus infection and replication in cells, protein dynamics, tumor diagnosis, and therapy evaluation. With the application of nanotechnology for CNS-active agents' delivery, nanostructured materials are emerging as a powerful means for diagnosis of CNS disorders, including brain tumors, because of their unique optical size, and surface properties. This review summarizes the recent patents on imaging nanoprobes for brain tumor diagnosis and therapy. The future development in this active cross-disciplinary field will be discussed as well. PMID:20156135

  11. Binary Plutinos

    NASA Astrophysics Data System (ADS)

    Noll, Keith S.

    2015-08-01

    The Pluto-Charon binary was the first trans-neptunian binary to be identified in 1978. Pluto-Charon is a true binary with both components orbiting a barycenter located between them. The Pluto system is also the first, and to date only, known binary with a satellite system consisting of four small satellites in near-resonant orbits around the common center of mass. Seven other Plutinos, objects in 3:2 mean motion resonance with Neptune, have orbital companions including 2004 KB19 reported here for the first time. Compared to the Cold Classical population, the Plutinos differ in the frequency of binaries, the relative sizes of the components, and their inclination distribution. These differences point to distinct dynamical histories and binary formation processes encountered by Plutinos.

  12. Magnetic Force Nanoprobe for Direct Observation of Audio Frequency Tonotopy of Hair Cells.

    PubMed

    Kim, Ji-Wook; Lee, Jae-Hyun; Ma, Ji-Hyun; Chung, Eunna; Choi, Hongsuh; Bok, Jinwoong; Cheon, Jinwoo

    2016-06-01

    Sound perception via mechano-sensation is a remarkably sensitive and fast transmission process, converting sound as a mechanical input to neural signals in a living organism. Although knowledge of auditory hair cell functions has advanced over the past decades, challenges remain in understanding their biomechanics, partly because of their biophysical complexity and the lack of appropriate probing tools. Most current studies of hair cells have been conducted in a relatively low-frequency range (<1000 Hz); therefore, fast kinetic study of hair cells has been difficult, even though mammalians have sound perception of 20 kHz or higher. Here, we demonstrate that the magnetic force nanoprobe (MFN) has superb spatiotemporal capabilities to mechanically stimulate spatially-targeted individual hair cells with a temporal resolution of up to 9 μs, which is equivalent to approximately 50 kHz; therefore, it is possible to investigate avian hair cell biomechanics at different tonotopic regions of the cochlea covering a full hearing frequency range of 50 to 5000 Hz. We found that the variation of the stimulation frequency and amplitude of hair bundles creates distinct mechanical responsive features along the tonotopic axis, where the kinetics of the hair bundle recovery motion exhibits unique frequency-dependent characteristics: basal, middle, and apical hair bundles can effectively respond at their respective ranges of frequency. We revealed that such recovery kinetics possesses two different time constants that are closely related to the passive and active motilities of hair cells. The use of MFN is critical for the kinetics study of free-standing hair cells in a spatiotemporally distinct tonotopic organization. PMID:27215487

  13. Performance characteristics of guanine incorporated PVDF-HFP/PEO polymer blend electrolytes with binary iodide salts for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Senthil, R. A.; Theerthagiri, J.; Madhavan, J.; Arof, A. K.

    2016-08-01

    In this work, we have investigated the influence of guanine as an organic dopant in dye-sensitized solar cell (DSSC) based on poly(vinylidinefluoride-co-hexafluoropropylene) (PVDF-HFP)/polyethylene oxide (PEO) polymer blend electrolyte along with binary iodide salts (potassium iodide (KI) and tetrabutylammonium iodide (TBAI)) and iodine (I2). The PVDF-HFP/KI + TBAI/I2, PVDF-HFP/PEO/KI + TBAI/I2 and guanine incorporated PVDF-HFP/PEO/KI + TBAI/I2 electrolytes were prepared by solution casting technique using DMF as solvent. The PVDF-HFP/KI + TBAI/I2 electrolyte showed an ionic conductivity value of 9.99 × 10-5 Scm-1, whereas, it was found to be increased to 4.53 × 10-5 Scm-1 when PEO was blended with PVDF-HFP/KI + TBAI/I2 electrolyte. However, a maximum ionic conductivity value of 3.67 × 10-4 Scm-1 was obtained for guanine incorporated PVDF-HFP/PEO/KI + TBAI/I2 blend electrolyte. The photovoltaic properties of all these polymer electrolytes in DSSCs were characterized. As a consequence, the power conversion efficiency of the guanine incorporated PVDF-HFP/PEO/KI + TBAI/I2 electrolyte based DSSC was significantly improved to 4.98% compared with PVDF-HFP/PEO/KI + TBAI/I2 electrolyte based DSSC (2.46%). These results revealed that the guanine can be an effective organic dopant to enhance the performance of DSSCs.

  14. Efficient Two-Photon Fluorescence Nanoprobe for Turn-On Detection and Imaging of Ascorbic Acid in Living Cells and Tissues.

    PubMed

    Meng, Hong-Min; Zhang, Xiao-Bing; Yang, Chan; Kuai, Hailan; Mao, Guo-Jiang; Gong, Liang; Zhang, Wenhan; Feng, Suling; Chang, Junbiao

    2016-06-01

    Ascorbic acid (AA) serves as a key coenzyme in many metabolic pathways, and its abnormal level is found to be associated with several diseases. Therefore, monitoring AA level in living systems is of great biomedical significance. In comparison with one-photon excited fluorescent probes, two-photon (TP) excited probes are more suitable for bioimaging, as they could afford higher imaging resolution with deeper imaging depth. Here, we report for the first time an efficient TP fluorescence probe for turn-on detection and imaging of AA in living cells and tissues. In this nanosystem, the negatively charged two-photon nanoparticles (TPNPs), which were prepared by modifying the silica nanoparticles with a two-photon dye, could adsorb cobalt oxyhydroxide (CoOOH) nanoflakes which carried positive charge by electrostatic force, leading to a remarkable decrease in their fluorescence intensity. However, the introduction of AA could induce the fluorescence recovery of the nanoprobe because it could reduce CoOOH into Co(2+) and result in the destruction of the CoOOH nanoflakes. The nanosystem exhibits a high sensitivity toward AA, with a LOD of 170 nM observed. It also shows high selectivity toward AA over common potential interfering species. The nanoprobe possessed both the advantages of TP imaging and excellent membrane-permeability and good biocompatibility of the silica nanoparticles and was successfully applied in TP-excited imaging of AA in living cells and tissues. PMID:27161421

  15. Fluorescent and bioluminescent nanoprobes for in vitro and in vivo detection of matrix metalloproteinase activity

    PubMed Central

    Lee, Hawon; Kim, Young-Pil

    2015-01-01

    Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that degrade the extracellular matrix (ECM) and regulate the extracellular microenvironment. Despite the significant role that MMP activity plays in cell-cell and cell-ECM interactions, migration, and differentiation, analyses of MMPs in vitro and in vivo have relied upon their abundance using conventional immunoassays, rather than their enzymatic activities. To resolve this issue, diverse nanoprobes have emerged and proven useful as effective activity-based detection tools. Here, we review the recent advances in luminescent nanoprobes and their applications in in vitro diagnosis and in vivo imaging of MMP activity. Nanoprobes with the purpose of sensing MMP activity consist of recognition and detection units, which include MMP-specific substrates and luminescent (fluorescent or bioluminescent) nanoparticles, respectively. With further research into improvement of the optical performance, it is anticipated that luminescent nanoprobes will have great potential for the study of the functional roles of proteases in cancer biology and nanomedicine. [BMB Reports 2015; 48(6): 313-318] PMID:25817215

  16. Investigation of apoptotic events at molecular level induced by SERS guided targeted theranostic nanoprobe.

    PubMed

    Narayanan, Nisha; Nair, Lakshmi V; Karunakaran, Varsha; Joseph, Manu M; Nair, Jyothi B; N, Ramya A; Jayasree, Ramapurath S; Maiti, Kaustabh Kumar

    2016-06-01

    Herein, we have examined distinctive structural and functional variations of cellular components during apoptotic cell death induced by a targeted theranostic nanoprobe, MMP-SQ@GNR@LAH-DOX, which acted as a SERS "on/off" probe in the presence of a MMP protease and executed synergistic photothermal chemotherapy, as reflected by the SERS fingerprinting, corresponding to the phosphodiester backbone of DNA. PMID:27211810

  17. A robot-based detector manipulator system for a hard x-ray nanoprobe instrument.

    SciTech Connect

    Shu, D., Maser, J., Holt, M. , Winarski, R., Preissner, C.,Lai, B., Vogt, S., Stephenson, G.B.

    2007-11-11

    This paper presents the design of a robot-based detector manipulator for microdiffraction applications with a hard X-ray nanoprobe instrument system being constructed at the Advanced Photon Source (APS) for the Center for Nanoscale Materials (CNM) being constructed at Argonne National Laboratory (ANL). Applications for detectors weighing from 1.5 to 100 kg were discussed in three configurations.

  18. Multifunctional nanoprobe for cancer cell targeting and simultaneous fluorescence/magnetic resonance imaging.

    PubMed

    Wei, Zhenzhen; Wu, Yafeng; Zhao, Yuewu; Mi, Li; Wang, Jintao; Wang, Jimin; Zhao, Jinjin; Wang, Lixin; Liu, Anran; Li, Ying; Wei, Wei; Zhang, Yuanjian; Liu, Songqin

    2016-09-28

    Multifunctional nanoprobes with distinctive magnetic and fluorescent properties are highly useful in accurate and early cancer diagnosis. In this study, nanoparticles of Fe3O4 core with fluorescent SiO2 shell (MFS) are synthesized by a facile improved Stöber method. These nanoparticles owning a significant core-shell structure exhibit good dispersion, stable fluorescence, low cytotoxicity and excellent biocompatibility. TLS11a aptamer (Apt1), a specific membrane protein for human liver cancer cells which could be internalized into cells, is conjugated to the MFS nanoparticles through the formation of amide bond working as a target-specific moiety. The attached TLS11a aptamers on nanoparticles are very stable and can't be hydrolyzed by DNA hydrolytic enzyme in vivo. Both fluorescence and magnetic resonance imaging show significant uptake of aptamer conjugated nanoprobe by HepG2 cells compared to 4T1, SGC-7901 and MCF-7 cells. In addition, with the increasing concentration of the nanoprobe, T2-weighted MRI images of the as-treated HepG2 cells are significantly negatively enhanced, indicating that a high magnetic field gradient is generated by MFS-Apt1 which has been specifically captured by HepG2 cells. The relaxivity of nanoprobe is calculated to be 11.5 mg(-1)s(-1). The MR imaging of tumor-bearing nude mouse is also confirmed. The proposed multifunctional nanoprobe with the size of sub-100 nm has the potential to provide real-time imaging in early liver cancer cell diagnosis. PMID:27619098

  19. Binary stars.

    PubMed

    Paczynacuteski, B

    1984-07-20

    Most stars in the solar neighborhood are either double or multiple systems. They provide a unique opportunity to measure stellar masses and radii and to study many interesting and important phenomena. The best candidates for black holes are compact massive components of two x-ray binaries: Cygnus X-1 and LMC X-3. The binary radio pulsar PSR 1913 + 16 provides the best available evidence for gravitational radiation. Accretion disks and jets observed in close binaries offer a very good testing ground for models of active galactic nuclei and quasars. PMID:17749544

  20. A multifunctional mesoporous Fe3O4/SiO2/CdTe magnetic-fluorescent composite nanoprobe

    NASA Astrophysics Data System (ADS)

    Yin, Naiqiang; Wu, Ping; Liang, Guo; Cheng, Wenjing

    2016-03-01

    A multifunctional mesoporous, magnetic and fluorescent Fe3O4/SiO2/CdTe nanoprobe with well-defined core-shell nanostructures was prepared. This multifunctional nanoprobe was synthesized through a novel method mainly including two steps. The first step involved the controlled growth of mesoporous silica layer onto the surface of Fe3O4 nanoparticle using tetraethyl orthosilicate as silica source, cationic surfactant cetyltrimethylammonium bromide as template, and 1,3,5-triisopropylbenzene as pore swelling agents. The second step involved the layer-by-layer assembly of 3-aminopropyltrimethoxysilane and fluorescent CdTe quantum dots with the mesoporous Fe3O4/SiO2 nanoparticles. The well-designed nanoprobe exhibits strong excitonic photoluminescence and superparamagnetism at room temperature. In attention, the mesoporous silica layer of the nanoprobe with great loading capacity makes it a promising candidate as targeted drug delivery platform.

  1. A New Polymer Nanoprobe Based on Chemiluminescence Resonance Energy Transfer for Ultrasensitive Imaging of Intrinsic Superoxide Anion in Mice.

    PubMed

    Li, Ping; Liu, Lu; Xiao, Haibin; Zhang, Wei; Wang, Lulin; Tang, Bo

    2016-03-01

    Despite significant developments in optical imaging of superoxide anion (O2(•-)) as the preliminary reactive oxygen species, novel visualizing strategies that offer ultrahigh sensitivity are still imperative. This is mainly because intrinsic concentrations of O2(•-) are extremely low in living systems. Herein, we present the rational design and construction of a new polymer nanoprobe PCLA-O2(•-) for detecting O2(•-) based on chemiluminescence (CL) resonance energy transfer without an external excitation source. Structurally, PCLA-O2(•-) contains two moieties linked covalently, namely imidazopyrazinone that is capable of CL triggered by O2(•-) as the energy donor and conjugated polymers with light-amplifying property as the energy acceptor. Experiment results demonstrate that PCLA-O2(•-) exhibits ultrahigh sensitivity at the picomole level, dramatically prolonged luminescence time, specificity, and excellent biocompatibility. Without exogenous stimulation, this probe for the first time in situ visualizes O2(•-) level differences between normal and tumor tissues of mice. These exceptional features ensure that PCLA-O2(•-) as a self-luminescing probe is an alternative in vivo imaging approach for ultralow level O2(•-). PMID:26908223

  2. A NaYbF4: Tm3+ nanoprobe for CT and NIR-to-NIR fluorescent bimodal imaging.

    PubMed

    Xing, Huaiyong; Bu, Wenbo; Ren, Qingguo; Zheng, Xiangpeng; Li, Ming; Zhang, Shengjian; Qu, Haiyun; Wang, Zheng; Hua, Yanqing; Zhao, Kuaile; Zhou, Liangping; Peng, Weijun; Shi, Jianlin

    2012-07-01

    Early diagnosis that combines the high-resolutional CT and sensitive NIR-fluorescence bioimaging could provide more accurate information for cancerous tissues, which, however, remain a big challenge. Here we report a simple bimodal imaging platform based on PEGylated NaYbF(4): Tm(3+) nanoparticles (NPs) of less than 20 nm in diameter for both CT and NIR-fluorescence bioimaging. The as-designed nanoprobes showed excellent in vitro and in vivo performances in the dual-bioimaging, very low cytotoxicity and no detectable tissue damage in one month. Remarkably, the Yb(3+) in the lattice of NaYbF(4): Tm(3+) NPs functions not only as a promising CT contrast medium due to its high X-ray absorption coefficiency, but also an excellent sensitizer contributing to the strong NIR-fluorescent emissions for its large NIR absorption cross-section. In addition, these NPs could be easily excreted mainly via feces without detectable remnant in the animal bodies. PMID:22538199

  3. Nanobiophotonics for molecular imaging of cancer: Au- and Ag-based Epidermal Growth Factor receptor (EGFR) specific nanoprobes

    NASA Astrophysics Data System (ADS)

    Lucas, Leanne J.; Hewitt, Kevin C.

    2012-03-01

    Our aim is to create and validate a novel SERS-based nanoprobe for optical imaging of the epidermal growth factor receptor (EGFR). Gold and silver nanoparticles (Au/AgNPs) of various sizes were synthesized and coupled to epidermal growth factor (EGF) via a short ligand, α-lipoic acid (206 g/mol), which binds strongly to both Au and Ag nanoparticles via its disulfide end group. We used carbodiimide chemistry to couple EGF to α-lipoic acid. These nanoprobes were tested for binding affinity using Enzyme Linked ImmunoSorbent Assay (ELISA) and, in-vitro, using EGFRoverexpressing A431 cells. The nanoprobes show excellent EGFR-specific binding. Time of Flight Mass Spectrometry demonstrate the carbodiimide based linking of the carboxylic acid end-group of α-lipoic acid to one or more of the three (terminal, or 2 lysine) amine groups on EGF. ELISA confirms that the linked EGF is active by itself, and following conjugation with gold or silver nanoparticles. Compared with bare nanoparticles, UV-Vis spectroscopy of Ag-based nanoprobes exhibit significant plasmon red-shift, while there was no discernable shift for Au-based ones. Dark field microscopy shows abundant uptake by EGFR overexpressing A431 cells, and serves to further confirm the excellent binding affinity. Nanoprobe internalization and consequent aggregation is thought to be the basis of enhanced light scattering in the dark field images, supporting the notion that these nanoprobes should provide excellent SERS signals at all nanoprobe sizes. In summary, novel EGFR-specific nanoprobes have been synthesized and validated by standard assay and in cell culture for use as SERS optical imaging probes.

  4. Real-time detection of implant-associated neutrophil responses using a formyl peptide receptor-targeting NIR nanoprobe

    PubMed Central

    Zhou, Jun; Tsai, Yi-Ting; Weng, Hong; Tang, Ewin N; Nair, Ashwin; Davé, Digant P; Tang, Liping

    2012-01-01

    Neutrophils play an important role in implant-mediated inflammation and infection. Unfortunately, current methods which monitor neutrophil activity, including enzyme measurements and histological evaluation, require many animals and cannot be used to accurately depict the dynamic cellular responses. To understand the neutrophil interactions around implant-mediated inflammation and infection it is critical to develop methods which can monitor in vivo cellular activity in real time. In this study, formyl peptide receptor (FPR)-targeting near-infrared nanoprobes were fabricated. This was accomplished by conjugating near-infrared dye with specific peptides having a high affinity to the FPRs present on activated neutrophils. The ability of FPR-targeting nanoprobes to detect and quantify activated neutrophils was assessed both in vitro and in vivo. As expected, FPR-targeting nanoprobes preferentially accumulated on activated neutrophils in vitro. Following transplantation, FPR-targeting nanoprobes preferentially accumulated at the biomaterial implantation site. Equally important, a strong relationship was observed between the extent of fluorescence intensity in vivo and the number of recruited neutrophils at the implantation site. Furthermore, FPR-targeting nanoprobes may be used to detect and quantify the number of neutrophils responding to a catheter-associated infection. The results show that FPR-targeting nanoprobes may serve as a powerful tool to monitor and measure the extent of neutrophil responses to biomaterial implants in vivo. PMID:22619542

  5. Moving graphene devices from lab to market: advanced graphene-coated nanoprobes

    NASA Astrophysics Data System (ADS)

    Hui, Fei; Vajha, Pujashree; Shi, Yuanyuan; Ji, Yanfeng; Duan, Huiling; Padovani, Andrea; Larcher, Luca; Li, Xiao Rong; Xu, Jing Juan; Lanza, Mario

    2016-04-01

    After more than a decade working with graphene there is still a preoccupying lack of commercial devices based on this wonder material. Here we report the use of high-quality solution-processed graphene sheets to fabricate ultra-sharp probes with superior performance. Nanoprobes are versatile tools used in many fields of science, but they can wear fast after some experiments, reducing the quality and increasing the cost of the research. As the market of nanoprobes is huge, providing a solution for this problem should be a priority for the nanotechnology industry. Our graphene-coated nanoprobes not only show enhanced lifetime, but also additional unique properties of graphene, such as hydrophobicity. Moreover, we have functionalized the surface of graphene to provide piezoelectric capability, and have fabricated a nano relay. The simplicity and low cost of this method, which can be used to coat any kind of sharp tip, make it suitable for the industry, allowing production on demand.After more than a decade working with graphene there is still a preoccupying lack of commercial devices based on this wonder material. Here we report the use of high-quality solution-processed graphene sheets to fabricate ultra-sharp probes with superior performance. Nanoprobes are versatile tools used in many fields of science, but they can wear fast after some experiments, reducing the quality and increasing the cost of the research. As the market of nanoprobes is huge, providing a solution for this problem should be a priority for the nanotechnology industry. Our graphene-coated nanoprobes not only show enhanced lifetime, but also additional unique properties of graphene, such as hydrophobicity. Moreover, we have functionalized the surface of graphene to provide piezoelectric capability, and have fabricated a nano relay. The simplicity and low cost of this method, which can be used to coat any kind of sharp tip, make it suitable for the industry, allowing production on demand. Electronic

  6. Tunable and amplified Raman gold nanoprobes for effective tracking (TARGET): in vivo sensing and imaging

    NASA Astrophysics Data System (ADS)

    Gandra, Naveen; Hendargo, Hansford C.; Norton, Stephen J.; Fales, Andrew M.; Palmer, Gregory M.; Vo-Dinh, Tuan

    2016-04-01

    We describe the development of a highly tunable, physiologically stable, and ultra-bright Raman probe, named as TARGET (Tunable and Amplified Raman Gold Nanoprobes for Effective Tracking), for in vitro and in vivo surface-enhanced Raman scattering (SERS) applications. The TARGET structure consists of a gold core inside a larger gold shell with a tunable interstitial gap similar to a ``nanorattle'' structure. The combination of galvanic replacement and the seed mediated growth method was employed to load Raman reporter molecules and subsequently close the pores to prevent leaking and degradation of reporters under physiologically extreme conditions. Precise tuning of the core-shell gap width, core size, and shell thickness allows us to modulate the plasmonic effect and achieve a maximum electric-field (E-field) intensity. The interstitial gap of TARGET nanoprobes can be designed to exhibit a plasmon absorption band at 785 nm, which is in resonance with the dye absorption maximum and lies in the ``tissue optical window'', resulting in ultra-bright SERS signals for in vivo studies. The results of in vivo measurements of TARGETs in laboratory mice illustrated the usefulness of these nanoprobes for medical sensing and imaging.We describe the development of a highly tunable, physiologically stable, and ultra-bright Raman probe, named as TARGET (Tunable and Amplified Raman Gold Nanoprobes for Effective Tracking), for in vitro and in vivo surface-enhanced Raman scattering (SERS) applications. The TARGET structure consists of a gold core inside a larger gold shell with a tunable interstitial gap similar to a ``nanorattle'' structure. The combination of galvanic replacement and the seed mediated growth method was employed to load Raman reporter molecules and subsequently close the pores to prevent leaking and degradation of reporters under physiologically extreme conditions. Precise tuning of the core-shell gap width, core size, and shell thickness allows us to modulate the

  7. Binary Asteroids

    NASA Astrophysics Data System (ADS)

    Harris, Alan W.; Pravec, P.

    2006-06-01

    There are now nearly 100 binary asteroids known. In the last year alone, 30 binary asteroids have been discovered, half of them by lightcurves showing eclipse events. Similar to eclipsing binary stars, such observations allow determination of orbit period and sizes and shapes of the primary and secondary relative to the orbital dimension. From these parameters one can estimate the mean density of the system, and a number of dynamical properties such as total specific angular momentum, tidal evolution time scales of spins and orbit, and precession frequencies of the orbit about the primary and of the solar induced "general precession" of the system. We have extracted parameters for all systems with enough observations to allow meaningful determinations. Some preliminary results include: (1) Binaries are roughly as prevalent among small main-belt asteroids as among Near-Earth Asteroids. (2) Most binaries are partially asynchronous, with the secondary synchronized to the orbit period, but the primary still spinning much faster. This is consistent with estimated tidal damping time scales. (3) Most systems have near the critical maximum angular momentum for a single "rubble pile" body, but not much more, and some less. Thus fission appears not to be a viable formation mechanism for all binaries, although near-critical spin rate seems to play a role. (4) Orbits of the secondaries are essentially in the equatorial plane of the primary. Since most primary spins are still fast, the satellites must have been formed into low inclination orbits. (5) Precession frequencies are in the range of the shorter resonance frequencies in the solar system (tens of thousands of years), thus resonance interactions can be expected to have altered spin orientations as systems evolved slowly by tidal friction or other processes. (6) Primaries are unusually spheroidal, which is probably necessary for stability of the binary once formed.

  8. NIR-to-NIR two-photon excited CaF2:Tm3+,Yb3+ nanoparticles: multifunctional nanoprobes for highly penetrating fluorescence bio-imaging.

    PubMed

    Dong, Ning-Ning; Pedroni, Marco; Piccinelli, Fabio; Conti, Giamaica; Sbarbati, Andrea; Ramírez-Hernández, Juan Enrique; Maestro, Laura Martínez; Iglesias-de la Cruz, Maria Carmen; Sanz-Rodriguez, Francisco; Juarranz, Angeles; Chen, Feng; Vetrone, Fiorenzo; Capobianco, John A; Solé, José García; Bettinelli, Marco; Jaque, Daniel; Speghini, Adolfo

    2011-11-22

    In this study, we report on the remarkable two-photon excited fluorescence efficiency in the "biological window" of CaF(2):Tm(3+),Yb(3+) nanoparticles. On the basis of the strong Tm(3+) ion emission (at around 800 nm), tissue penetration depths as large as 2 mm have been demonstrated, which are more than 4 times those achievable based on the visible emissions in comparable CaF(2):Er(3+),Yb(3+) nanoparticles. The outstanding penetration depth, together with the fluorescence thermal sensitivity demonstrated here, makes CaF(2):Tm(3+),Yb(3+) nanoparticles ideal candidates as multifunctional nanoprobes for high contrast and highly penetrating in vivo fluorescence imaging applications. PMID:21957870

  9. Investigation of apoptotic events at molecular level induced by SERS guided targeted theranostic nanoprobe

    NASA Astrophysics Data System (ADS)

    Narayanan, Nisha; Nair, Lakshmi V.; Karunakaran, Varsha; Joseph, Manu M.; Nair, Jyothi B.; N, Ramya A.; Jayasree, Ramapurath S.; Maiti, Kaustabh Kumar

    2016-06-01

    Herein, we have examined distinctive structural and functional variations of cellular components during apoptotic cell death induced by a targeted theranostic nanoprobe, MMP-SQ@GNR@LAH-DOX, which acted as a SERS ``on/off'' probe in the presence of a MMP protease and executed synergistic photothermal chemotherapy, as reflected by the SERS fingerprinting, corresponding to the phosphodiester backbone of DNA.Herein, we have examined distinctive structural and functional variations of cellular components during apoptotic cell death induced by a targeted theranostic nanoprobe, MMP-SQ@GNR@LAH-DOX, which acted as a SERS ``on/off'' probe in the presence of a MMP protease and executed synergistic photothermal chemotherapy, as reflected by the SERS fingerprinting, corresponding to the phosphodiester backbone of DNA. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03385g

  10. Investigations of electrical transport properties of individual carbon nanotubes with nanoprober

    NASA Astrophysics Data System (ADS)

    Feng, Wei; Hayama, Kazumi; Akinaga, Hiroyuki

    2016-06-01

    We investigated and discussed quantitatively the transport properties of individual multiwalled (MW) carbon nanotubes (CNTs) by four-terminal measurement using a nanoprobing system. The homogeneity of the CNT was visibly examined using the electron beam absorbed current function of the nanoprober. The observed ohmic properties of the current–voltage characteristics and metallic transport properties of the CNTs proved that reliable contact of four probes was achieved on the outermost shell of MWCNTs. The experimental methodology was validated for the intrinsic properties of individual CNTs. Lower resistance per unit length was evaluated for thicker CNT. The measured resistance per unit length was lower than those reported by other researchers, but higher than ideally expected.

  11. Three-Dimensional Rapid Prototyping of Multidirectional Polymer Nanoprobes for Single Cell Insertion.

    PubMed

    Yang, Dasom; Hong, Hyeonaug; Seo, Yoon Ho; Kim, Lo Hyun; Ryu, WonHyoung

    2015-08-01

    Three-dimensional (3D) thermal drawing at nanoscale as a novel rapid prototyping method was demonstrated to create multidirectional polymer nanoprobes for single cell analysis. This 3D drawing enables simple and rapid fabrication of polymeric nanostructures with high aspect ratio. The effect of thermal drawing parameters, such as drawing speeds, dipping depths, and contact duration on the final geometry of polymer nanostructures was investigated. Vertically aligned and L-shaped nanoprobes were fabricated and their insertion into living single cells such as algal cells and human neural stem cells was demonstrated. This technique can be extended to create more complex 3D structures by controlling drawing steps and directions on any surface. PMID:26144221

  12. Label-Free Carbon-Dots-Based Ratiometric Fluorescence pH Nanoprobes for Intracellular pH Sensing.

    PubMed

    Shangguan, Jingfang; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Xu, Fengzhou; Liu, Jinquan; Tang, Jinlu; Yang, Xue; Huang, Jin

    2016-08-01

    Measuring pH in living cells is of great importance for better understanding cellular functions as well as providing pivotal assistance for early diagnosis of diseases. In this work, we report the first use of a novel kind of label-free carbon dots for intracellular ratiometric fluorescence pH sensing. By simple one-pot hydrothermal treatment of citric acid and basic fuchsin, the carbon dots showing dual emission bands at 475 and 545 nm under single-wavelength excitation were synthesized. It is demonstrated that the fluorescence intensities of the as-synthesized carbon dots at the two emissions are pH-sensitive simultaneously. The intensity ratio (I475 nm/I545 nm) is linear against pH values from 5.2 to 8.8 in buffer solution, affording the capability as ratiometric probes for intracellular pH sensing. It also displays that the carbon dots show excellent reversibility and photostability in pH measurements. With this nanoprobe, quantitative fluorescence imaging using the ratio of two emissions (I475 nm/I545 nm) for the detection of intracellular pH were successfully applied in HeLa cells. In contrast to most of the reported nanomaterials-based ratiometric pH sensors which rely on the attachment of additional dyes, these carbon-dots-based ratiometric probes are low in toxicity, easy to synthesize, and free from labels. PMID:27334762

  13. Targeted Near-Infrared Fluorescent Turn-on Nanoprobe for Activatable Imaging and Effective Phototherapy of Cancer Cells.

    PubMed

    Li, Na; Li, Tingting; Hu, Chao; Lei, Xiaomin; Zuo, Yunpeng; Han, Heyou

    2016-06-22

    A novel and green multifunctional nanoplatform as a nanocarrier for drug delivery, cell imaging, and phototherapy has been engineered. The nanoplatform is composed of stabilized carbon spheres (CSs) as cores, a coated polydopamine (PDA) shell, targeted folic acid (FA), and the loaded anticancer drug indocyanine green (ICG), obtaining CSs@PDA-FA@ICG nanocomposites (NCs). The biocompatible PDA shell provided a high fluorescence quenching efficiency and a surface rich in functional groups for anchoring FA for targeting cancer cells. Aromatic ICG could be effectively loaded into the CSs@PDA-FA system via hydrophobic interactions and π-π stacking with a loading efficiency of 58.9%. Notably, the activated NIR fluorescence in an intracellular environment made CSs@PDA-FA@ICG a sensitive "OFF" to "ON" nanoprobe that can be used for NIR imaging. Moreover, compared to ICG alone, the CSs@PDA-FA@ICG NCs could induce efficient photoconversion for simultaneous synergetic photodynamic therapy (PDT) and photothermal therapy (PTT) under a single NIR laser irradiation. The results demonstrated that CSs@PDA-FA@ICG NCs as a targeted and activated nanoplatform provide new opportunities to facilitate the accurate diagnosis of cancer and enhanced treatment efficacy. This work stimulates more interest in the design of the facile surface functionalization strategy to construct other multifunctional nanocomposites, such as nanotubes and nanorods. PMID:25996034

  14. Smart nanoprobes for the detection of alkaline phosphatase activity during osteoblast differentiation.

    PubMed

    Lim, Eun-Kyung; Keem, Joo Oak; Yun, Hui-suk; Jung, Jinyoung; Chung, Bong Hyun

    2015-02-21

    Gold nanoparticle-conjugated fluorescent hydroxyapatite (AuFHAp) was developed as a smart nanoprobe for measuring alkaline phosphatase (ALP) activity. AuFHAp showed NIR fluorescence due to the hydrolysis of its phosphate groups by ALP. In addition, gold nanoparticles help reduce the nonspecific signal by absorbing nonspecific fluorescence. Through in vitro tests, we confirmed that the AuFHAp probe was capable of detecting ALP levels related to osteoblast activity in living cells with high fluorescence intensity. PMID:25623488

  15. Photoacoustic and Fluorescence Image-Guided Surgery Using a Multifunctional Targeted Nanoprobe

    PubMed Central

    Xi, Lei; Zhou, Guangyin; Gao, Ning; Yang, Lily; Gonzalo, David A.; Hughes, Steven J.; Jiang, Huabei

    2016-01-01

    Purpose A complete surgical excision with negative tumor margins is the single most important factor in the prediction of long-term survival for most cancer patients with solid tumors. We hypothesized that image-guided surgery using nanoparticle-enhanced photoacoustic and fluorescence imaging could significantly reduce the rate of local recurrence. Methods A murine model of invasive mammary carcinoma was utilized. Three experimental groups were included: (1) control; (2) tumor-bearing mice injected with non-targeted nanoprobe; and (3) tumor-bearing mice injected with targeted nanoprobe. The surgeon removed the primary tumor following the guidance of photoacoustic imaging (PAI), then inspected the surgical wound and removed the suspicious tissue using intraoperative near-infrared (NIR) fluorescence imaging. The mice were followed with bioluminescence imaging weekly to quantify local recurrence. Results Nanoprobe-enhanced photoacoustic contrast enabled PAI to map the volumetric tumor margins up to a depth of 31 mm. The targeted nanoparticles provided significantly greater enhancement than non-targeted nano-particles. Seven mice in the group injected with the targeted nanoprobes underwent additional resections based upon NIR fluorescence imaging. Pathological analysis confirmed residual cancer cells in the re-resected specimens in 5/7 mice. Image-guided resection resulted in a significant reduction in local recurrence; 8.7 and 33.3 % of the mice in the targeted and control groups suffered recurrence, respectively. Conclusions These results suggest that photoacoustic and NIR intraoperative imaging can effectively assist a surgeon to locate primary tumors and to identify residual disease in real-time. This technology has promise to overcome current clinical challenges that result in the need for second surgical procedures. PMID:24554061

  16. Tracking SERS-active nanoprobe intracellular uptake for chemical and biological sensing

    NASA Astrophysics Data System (ADS)

    Gregas, Molly K.; Yan, Fei; Scaffidi, Jonathan; Wang, Hsin-Neng; Khoury, Christopher; Zhang, Yan; Vo-Dinh, Tuan

    2007-09-01

    A critical aspect of the use of nanoprobes for intracellular studies in chemical and biological sensing involves a fundamental understanding of their uptake and trajectory in cells. In this study, we describe experiments using surface-enhanced Raman scattering (SERS) spectroscopy and mapping to track cellular uptake of plasmonics-active labeled nanoparticles. Three different Raman-active labels with positive, negative, and neutral charges were conjugated to silver colloidal nanoparticles with the aim of spatially and temporally profiling intracellular delivery and tracking of nanoprobes during uptake in single mammalian cells. 1-D Raman spectra and 2-D Raman mapping are used to identify and locate the probes via their SERS signal intensities. Because Raman spectroscopy is very specific for identification of chemical and molecular signatures, the development of functionalized plasmonics-active nanoprobes capable of exploring intracellular spaces and processes has the ability to provide specific information on the effects of biological and chemical pollutants in the intracellular environment. The results indicate that this technique will allow study of when, where, and how these substances affect cells and living organisms.

  17. Tunable and amplified Raman gold nanoprobes for effective tracking (TARGET): in vivo sensing and imaging.

    PubMed

    Gandra, Naveen; Hendargo, Hansford C; Norton, Stephen J; Fales, Andrew M; Palmer, Gregory M; Vo-Dinh, Tuan

    2016-04-28

    We describe the development of a highly tunable, physiologically stable, and ultra-bright Raman probe, named as TARGET (Tunable and Amplified Raman Gold Nanoprobes for Effective Tracking), for in vitro and in vivo surface-enhanced Raman scattering (SERS) applications. The TARGET structure consists of a gold core inside a larger gold shell with a tunable interstitial gap similar to a "nanorattle" structure. The combination of galvanic replacement and the seed mediated growth method was employed to load Raman reporter molecules and subsequently close the pores to prevent leaking and degradation of reporters under physiologically extreme conditions. Precise tuning of the core-shell gap width, core size, and shell thickness allows us to modulate the plasmonic effect and achieve a maximum electric-field (E-field) intensity. The interstitial gap of TARGET nanoprobes can be designed to exhibit a plasmon absorption band at 785 nm, which is in resonance with the dye absorption maximum and lies in the "tissue optical window", resulting in ultra-bright SERS signals for in vivo studies. The results of in vivo measurements of TARGETs in laboratory mice illustrated the usefulness of these nanoprobes for medical sensing and imaging. PMID:27064259

  18. A choline derivate-modified nanoprobe for glioma diagnosis using MRI

    NASA Astrophysics Data System (ADS)

    Li, Jianfeng; Huang, Shixian; Shao, Kun; Liu, Yang; An, Sai; Kuang, Yuyang; Guo, Yubo; Ma, Haojun; Wang, Xuxia; Jiang, Chen

    2013-04-01

    Gadolinium (Gd) chelate contrast-enhanced magnetic resonance imaging (MRI) is a preferred method of glioma detection and preoperative localisation because it offers high spatial resolution and non-invasive deep tissue penetration. Gd-based contrast agents, such as Gd-diethyltriaminepentaacetic acid (DTPA-Gd, Magnevist), are widely used clinically for tumor diagnosis. However, the Gd-based MRI approach is limited for patients with glioma who have an uncompromised blood-brain barrier (BBB). Moreover, the rapid renal clearance and non-specificity of such contrast agents further hinders their prevalence. We present a choline derivate (CD)-modified nanoprobe with BBB permeability, glioma specificity and a long blood half-life. Specific accumulation of the nanoprobe in gliomas and subsequent MRI contrast enhancement are demonstrated in vitro in U87 MG cells and in vivo in a xenograft nude model. BBB and glioma dual targeting by this nanoprobe may facilitate precise detection of gliomas with an uncompromised BBB and may offer better preoperative and intraoperative tumor localization.

  19. Au-nanoprobes for detection of SNPs associated with antibiotic resistance in Mycobacterium tuberculosis

    NASA Astrophysics Data System (ADS)

    Veigas, Bruno; Machado, Diana; Perdigão, João; Portugal, Isabel; Couto, Isabel; Viveiros, Miguel; Baptista, Pedro V.

    2010-10-01

    Tuberculosis (TB) is one of the leading causes of infection in humans, causing high morbility and mortality all over the world. The rate of new cases of multidrug resistant tuberculosis (MDRTB) continues to increase, and since these infections are very difficult to manage, they constitute a serious health problem. In most cases, drug resistance in Mycobacterium tuberculosis has been related to mutations in several loci within the pathogen's genome. The development of fast, cheap and simple screening methodologies would be of paramount relevance for the early detection of these mutations, essential for the timely and effective diagnosis and management of MDRTB patients. The use of gold nanoparticles derivatized with thiol-modified oligonucleotides (Au-nanoprobes) has led to new approaches in molecular diagnostics. Based on the differential non-cross-linking aggregation of Au-nanoprobes, we were able to develop a colorimetric method for the detection of specific sequences and to apply this approach to pathogen identification and single base mutations/single nucleotide polymorphisms (SNP) discrimination. Here we report on the development of Au-nanoprobes for the specific identification of SNPs within the beta subunit of the RNA polymerase (rpoB locus), responsible for resistance to rifampicin in over 95% of rifampicin resistant M. tuberculosis strains.

  20. Epidermal Growth Factor Receptor-Specific Nanoprobe Biodistribution in Mouse Models.

    PubMed

    Lee, Christopher L D; Fashir, Samia B; Castilho, Maiara L; Hupman, Michael A; Raniero, Leandro J; Alwayn, Ian; Hewitt, Kevin C

    2016-01-01

    Nanotechnology offers a targeted approach to both imaging and treatment of cancer, the leading cause of death worldwide. Previous studies have found that nanoparticles with a wide variety of coatings initiate an immune response leading to sequestration in the liver and spleen. In an effort to find a nanoparticle platform which does not elicit an immune response, we created 43 nm and 44 nm of gold and silver nanoparticles coated with biomolecules normally produced by the body, α-lipoic acid and the epidermal growth factor (EGF), and have used mass spectroscopy to determine their biodistribution in mouse models, 24 h after tail vein injection. Relative to controls, mouse EGF (mEGF)-coated silver and gold nanoprobes are found at background levels in all organs including the liver and spleen. The lack of sequestration of mEGF-coated nanoprobes in the liver and spleen and the corresponding uptake of control nanoprobes at elevated levels in these organs suggest that the former are not recognized by the immune system. Further studies of cytokine and interleukin levels in the blood are required to confirm avoidance of an immune response. PMID:26852838

  1. New binary systems: beaming binaries

    NASA Astrophysics Data System (ADS)

    Morales, J. C.; Weingrill, J.; Mazeh, T.; Ribas, I.

    2011-11-01

    Exoplanet missions such as COROT and Kepler are providing precise photometric follow-up data of new kinds of variable stars undetected till now. Beaming binaries are among these objects. On these binary systems, the orbital motion of their components is fast enough to produce a detectable modulation on the received flux due to relativistic effects (Zucker et al. 2007). The great advantage of these systems is that it is possible to reconstruct the radial velocity curve of the system from this photometric modulation and thus, orbital parameters such as the mass ratio and the semi-major axis can be estimated from photometry without the necessity of spectroscopic follow-up. In this poster, we briefly introduce the analysis of this kind of binary systems and in particular, the eclipsing cases.

  2. Binary Planets

    NASA Astrophysics Data System (ADS)

    Ryan, Keegan; Nakajima, Miki; Stevenson, David J.

    2014-11-01

    Can a bound pair of similar mass terrestrial planets exist? We are interested here in bodies with a mass ratio of ~ 3:1 or less (so Pluto/Charon or Earth/Moon do not qualify) and we do not regard the absence of any such discoveries in the Kepler data set to be significant since the tidal decay and merger of a close binary is prohibitively fast well inside of 1AU. SPH simulations of equal mass “Earths” were carried out to seek an answer to this question, assuming encounters that were only slightly more energetic than parabolic (zero energy). We were interested in whether the collision or near collision of two similar mass bodies would lead to a binary in which the two bodies remain largely intact, effectively a tidal capture hypothesis though with the tidal distortion being very large. Necessarily, the angular momentum of such an encounter will lead to bodies separated by only a few planetary radii if capture occurs. Consistent with previous work, mostly by Canup, we find that most impacts are disruptive, leading to a dominant mass body surrounded by a disk from which a secondary forms whose mass is small compared to the primary, hence not a binary planet by our adopted definition. However, larger impact parameter “kissing” collisions were found to produce binaries because the dissipation upon first encounter was sufficient to provide a bound orbit that was then rung down by tides to an end state where the planets are only a few planetary radii apart. The long computational times for these simulation make it difficult to fully map the phase space of encounters for which this outcome is likely but the indications are that the probability is not vanishingly small and since planetary encounters are a plausible part of planet formation, we expect binary planets to exist and be a non-negligible fraction of the larger orbital radius exoplanets awaiting discovery.

  3. Microlensing Signature of Binary Black Holes

    NASA Technical Reports Server (NTRS)

    Schnittman, Jeremy; Sahu, Kailash; Littenberg, Tyson

    2012-01-01

    We calculate the light curves of galactic bulge stars magnified via microlensing by stellar-mass binary black holes along the line-of-sight. We show the sensitivity to measuring various lens parameters for a range of survey cadences and photometric precision. Using public data from the OGLE collaboration, we identify two candidates for massive binary systems, and discuss implications for theories of star formation and binary evolution.

  4. Separation in 5 Msun Binaries

    NASA Astrophysics Data System (ADS)

    Evans, Nancy R.; Bond, H. E.; Schaefer, G.; Mason, B. D.; Karovska, M.; Tingle, E.

    2013-01-01

    Cepheids (5 Msun stars) provide an excellent sample for determining the binary properties of fairly massive stars. International Ultraviolet Explorer (IUE) observations of Cepheids brighter than 8th magnitude resulted in a list of ALL companions more massive than 2.0 Msun uniformly sensitive to all separations. Hubble Space Telescope Wide Field Camera 3 (WFC3) has resolved three of these binaries (Eta Aql, S Nor, and V659 Cen). Combining these separations with orbital data in the literature, we derive an unbiased distribution of binary separations for a sample of 18 Cepheids, and also a distribution of mass ratios. The distribution of orbital periods shows that the 5 Msun binaries prefer shorter periods than 1 Msun stars, reflecting differences in star formation processes.

  5. Synthesis and characterization of an HSP27-targeted nanoprobe for in vivo photoacoustic imaging of early nerve injury.

    PubMed

    Chen, Hongjiang; Yang, Sihua; Zhou, Ting; Xu, Jiankun; Hu, Jun; Xing, Da

    2016-08-01

    Imaging is routinely used for clinical and diagnostic purposes, but techniques capable of high specificity and resolution for the early detection of nerve injury are still limited. In this study, we found that heat shock protein 27 (HSP27) becomes highly upregulated within 3 to 7 days of nerve injury. Taking advantage of this expression pattern, we conjugated gold nanorods (GNRs) to HSP27-specific antibodies to generate a nanoprobe (GNR-HSP27Abs) that could be targeted to the site of nerve injury and detected by near-infrared photoacoustic imaging. Notably, photoacoustic images acquired 12hours after local administration of GNR-HSP27Abs demonstrated that the nanoprobe can distinguish between injured and uninjured nerves in rats. Taken together, these findings expand the application of nanoprobe-targeted photoacoustic imaging to the detection of injured nerves, and prompt further development of this novel imaging platform for clinical application. PMID:27046663

  6. Development of Multifunctional Fluorescent-Magnetic Nanoprobes for Selective Capturing and Multicolor Imaging of Heterogeneous Circulating Tumor Cells.

    PubMed

    Pramanik, Avijit; Vangara, Aruna; Viraka Nellore, Bhanu Priya; Sinha, Sudarson Sekhar; Chavva, Suhash Reddy; Jones, Stacy; Ray, Paresh Chandra

    2016-06-22

    Circulating tumor cells (CTC) are highly heterogeneous in nature due to epithelial-mesenchymal transition (EMT), which is the major obstacle for CTC analysis via "liquid biopsy". This article reports the development of a new class of multifunctional fluorescent-magnetic multicolor nanoprobes for targeted capturing and accurate identification of heterogeneous CTC. A facile design approach for the synthesis and characterization of bioconjugated multifunctonal nanoprobes that exhibit excellent magnetic properties and emit very bright and photostable multicolor fluorescence at red, green, and blue under 380 nm excitation is reported. Experimental data presented show that the multifunctional multicolor nanoprobes can be used for targeted capture and multicolor fluorescence mapping of heterogeneous CTC and can distinguish targeted CTC from nontargeted cells. PMID:27255574

  7. Gold on paper-paper platform for Au-nanoprobe TB detection.

    PubMed

    Veigas, Bruno; Jacob, Jorge M; Costa, Mafalda N; Santos, David S; Viveiros, Miguel; Inácio, João; Martins, Rodrigo; Barquinha, Pedro; Fortunato, Elvira; Baptista, Pedro Viana

    2012-11-21

    Tuberculosis (TB) remains one of the most serious infectious diseases in the world and the rate of new cases continues to increase. The development of cheap and simple methodologies capable of identifying TB causing agents belonging to the Mycobacterium tuberculosis Complex (MTBC), at point-of-need, in particular in resource-poor countries where the main TB epidemics are observed, is of paramount relevance for the timely and effective diagnosis and management of patients. TB molecular diagnostics, aimed at reducing the time of laboratory diagnostics from weeks to days, still require specialised technical personnel and labour intensive methods. Recent nanotechnology-based systems have been proposed to circumvent these limitations. Here, we report on a paper-based platform capable of integrating a previously developed Au-nanoprobe based MTBC detection assay-we call it "Gold on Paper". The Au-nanoprobe assay is processed and developed on a wax-printed microplate paper platform, allowing unequivocal identification of MTBC members and can be performed without specialised laboratory equipment. Upon integration of this Au-nanoprobe colorimetric assay onto the 384-microplate, differential colour scrutiny may be captured and analysed with a generic "smartphone" device. This strategy uses the mobile device to digitalise the intensity of the colour associated with each colorimetric assay, perform a Red Green Blue (RGB) analysis and transfer relevant information to an off-site lab, thus allowing for efficient diagnostics. Integration of the GPS location metadata of every test image may add a new dimension of information, allowing for real-time epidemiologic data on MTBC identification. PMID:23000923

  8. X-ray-Induced Shortwave Infrared Biomedical Imaging Using Rare-Earth Nanoprobes

    PubMed Central

    2015-01-01

    Shortwave infrared (SWIR or NIR-II) light provides significant advantages for imaging biological structures due to reduced autofluorescence and photon scattering. Here, we report on the development of rare-earth nanoprobes that exhibit SWIR luminescence following X-ray irradiation. We demonstrate the ability of X-ray-induced SWIR luminescence (X-IR) to monitor biodistribution and map lymphatic drainage. Our results indicate X-IR imaging is a promising new modality for preclinical applications and has potential for dual-modality molecular disease imaging. PMID:25485705

  9. Nanoprobe studies: Electrical transport in carbon nanotubes and crystal structure of aluminum nitride surfaces

    NASA Astrophysics Data System (ADS)

    Biswas, Sujit Kumar

    Nanoprobes are an extraordinary set of experimental tools that allow fabrication, manipulation, and measurement in nano-scale systems. The primary use of a nanoprobe for imaging tiny objects is supplemented by powerful electrical techniques, namely scanning surface potential microscopy and current sensing atomic force microscopy. They allow us to measure potential, and current in carbon nanotube circuits. Nanoprobes are superior to conventional two- or four-probe measurements because they can provide spatial information of local electronic properties. This makes them highly attractive in studying junctions and contacts with carbon nanotubes. We have studied single-walled carbon nanotube circuits, forming junctions to other nanotubes. The experimental results indicate that these junctions act like potential barriers of about 50 meV that can confine electrons with an effective mass of 0.003 me , within nanotube channels of length 0.5 mum lying in-between two such potential barriers. This leads to quantization of the channel, forming a resonant tunneling structure. We have also found that single-walled nanotubes have phase coherence lengths of the order of 1 mum. This leads to situations where the electron interference effects at scattering centers need to be considered. We have seen direct evidence of this, in the non-linear resistance increase within nanotubes with few defects. Ambipolar transistor behavior was measured in a p-type single-walled nanotube circuit that showed electron injection across the Schottky junction at high positive bias. We have also studied multi-walled carbon nanotube circuits using scanning potential microscopy, and found that a back gate potential can vary the resistance of the channel. Vertical nanotube arrays, suitable for interconnects, were also measured. These hollow multi-walled nanotube channels were about 45 nm in diameter, and 50 mum in length, fabricated in an anodized alumina template. We found that these structures could

  10. Measurement of minority carrier diffusion lengths in GaAs nanowires by a nanoprobe technique

    NASA Astrophysics Data System (ADS)

    Darbandi, A.; Watkins, S. P.

    2016-07-01

    Minority carrier diffusion lengths in both p-type and n-type GaAs nanowires were studied using electron beam induced current by means of a nanoprobe technique without lithographic processing. The diffusion lengths were determined for Au/GaAs rectifying junctions as well as axial p-n junctions. By incorporating a thin lattice-matched InGaP passivating shell, a 2-fold enhancement in the minority carrier diffusion lengths and one order of magnitude reduction in the surface recombination velocity were achieved.

  11. Small-Protein-Stabilized Semiconductor Nanoprobe for Targeted Imaging of Cancer Cells.

    PubMed

    Zhao, Ning; Liu, Siyu; Jiang, Qike; Lan, Tian; Cheng, Zhen; Liu, Hongguang

    2016-07-01

    Recently, semiconductor nanoparticles such as quantum dots (QDs) have attracted significant attention for bioimaging. Complex chemical functionalization, surface modification, and bioconjugation chemistry are generally required to tag biomolecules to QDs for imaging of different biomarkers. In this study, we report a simple method for production of QDs stabilized by the small protein, Affibody (AF-QDs) for fluorescent imaging of the human epidermal growth factor receptor type 2 (HER2) in human A549 lung cancer cells. This one-pot synthesis of AF-QDs avoids complex chemical conjugation procedures and demonstrates a promising approach for the preparation of fluorescent nanoprobes for imaging of cancer targets. PMID:27123671

  12. CXCR-4 Targeted, Short Wave Infrared (SWIR) Emitting Nanoprobes for Enhanced Deep Tissue Imaging and Micrometastatic Lesion Detection

    PubMed Central

    Zevon, Margot; Ganapathy, Vidya; Kantamneni, Harini; Mingozzi, Marco; Kim, Paul; Adler, Derek; Sheng, Yang; Tan, Mei Chee; Pierce, Mark; Riman, Richard E.; Roth, Charles M.; Moghe, Prabhas V.

    2016-01-01

    Realizing the promise of precision medicine in cancer therapy depends on identifying and tracking of cancerous growths in order to maximize treatment options and improve patient outcomes. However, this goal of early detection remains unfulfilled by current clinical imaging techniques that fail to detect diseased lesions, due to their small size and sub-organ localization. With proper probes, optical imaging techniques can overcome this limitation by identifying the molecular phenotype of tumors at both macroscopic and microscopic scales. In this study, we propose the first use of nanophotonic short wave infrared technology to molecularly phenotype small sub-surface lesions for more sensitive detection and improved patient outcomes. To this end, we designed human serum albumin encapsulated rare-earth (RE) nanoparticles (ReANCs)[1, 2] with ligands for targeted lesion imaging. AMD3100, an antagonist to CXCR4 (a chemokine receptor involved in cell motility and a classic marker of cancer metastasis) was adsorbed onto ReANCs to form functionalized ReANCs (fReANCs). Functionalized nanoparticles were able to discriminate and preferentially accumulate in receptor positive lesions when injected intraperitoneally in a subcutaneous tumor model. Additionally, fReANCs, administered intravenously, were able to target sub-tissue tumor micro-lesions, at a maximum depth of 10.5 mm, in a lung metastatic model of breast cancer. Internal lesions identified with fReANCs were 2.25 times smaller than those detected with unfunctionalized ReANCs (p < .01) with the smallest tumor being 18.9 mm3. Thus, we present an integrated nanoprobe detection platform that allows target-specific identification of sub-tissue cancerous lesions. PMID:26514367

  13. A Next-Generation Hard X-Ray Nanoprobe Beamline for In Situ Studies of Energy Materials and Devices

    NASA Astrophysics Data System (ADS)

    Maser, Jörg; Lai, Barry; Buonassisi, Tonio; Cai, Zhonghou; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Jacobsen, Chris; Preissner, Curt; Roehrig, Chris; Rose, Volker; Shu, Deming; Vine, David; Vogt, Stefan

    2014-01-01

    The Advanced Photon Source is developing a suite of new X-ray beamlines to study materials and devices across many length scales and under real conditions. One of the flagship beamlines of the APS upgrade is the In Situ Nanoprobe (ISN) beamline, which will provide in situ and operando characterization of advanced energy materials and devices under varying temperatures, gas ambients, and applied fields, at previously unavailable spatial resolution and throughput. Examples of materials systems include inorganic and organic photovoltaic systems, advanced battery systems, fuel cell components, nanoelectronic devices, advanced building materials and other scientifically and technologically relevant systems. To characterize these systems at very high spatial resolution and trace sensitivity, the ISN will use both nanofocusing mirrors and diffractive optics to achieve spots sizes as small as 20 nm. Nanofocusing mirrors in Kirkpatrick-Baez geometry will provide several orders of magnitude increase in photon flux at a spatial resolution of 50 nm. Diffractive optics such as zone plates and/or multilayer Laue lenses will provide a highest spatial resolution of 20 nm. Coherent diffraction methods will be used to study even small specimen features with sub-10 nm relevant length scale. A high-throughput data acquisition system will be employed to significantly increase operations efficiency and usability of the instrument. The ISN will provide full spectroscopy capabilities to study the chemical state of most materials in the periodic table, and enable X-ray fluorescence tomography. In situ electrical characterization will enable operando studies of energy and electronic devices such as photovoltaic systems and batteries. We describe the optical concept for the ISN beamline, the technical design, and the approach for enabling a broad variety of in situ studies. We furthermore discuss the application of hard X-ray microscopy to study defects in multi-crystalline solar cells, one

  14. A Next-Generation Hard X-Ray Nanoprobe Beamline for In Situ Studies of Energy Materials and Devices

    SciTech Connect

    Maser, Jong; Lai, Barry; Buonassisi, Toni; Cai, Zhonghou; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Jacobsen, Chris; Preissner, Curt; Chris Roehrig; Rose, Volker; Shu, Deming; Vine, David; Vogt, Stefan

    2013-08-20

    The Advanced Photon Source is developing a suite of new X-ray beamlines to study materials and devices across many length scales and under real conditions. One of the flagship beamlines of the APS upgrade is the In Situ Nanoprobe (ISN) beamline, which will provide in situ and operando characterization of advanced energy materials and devices under varying temperatures, gas ambients, and applied fields, at previously unavailable spatial resolution and throughput. Examples of materials systems include inorganic and organic photovoltaic systems, advanced battery systems, fuel cell components, nanoelectronic devices, advanced building materials and other scientifically and technologically relevant systems. To characterize these systems at very high spatial resolution and trace sensitivity, the ISN will use both nanofocusing mirrors and diffractive optics to achieve spots sizes as small as 20 nm. Nanofocusing mirrors in Kirkpatrick–Baez geometry will provide several orders of magnitude increase in photon flux at a spatial resolution of 50 nm. Diffractive optics such as zone plates and/or multilayer Laue lenses will provide a highest spatial resolution of 20 nm. Coherent diffraction methods will be used to study even small specimen features with sub-10 nm relevant length scale. A high-throughput data acquisition system will be employed to significantly increase operations efficiency and usability of the instrument. The ISN will provide full spectroscopy capabilities to study the chemical state of most materials in the periodic table, and enable X-ray fluorescence tomography. In situ electrical characterization will enable operando studies of energy and electronic devices such as photovoltaic systems and batteries. We also describe the optical concept for the ISN beamline, the technical design, and the approach for enabling a broad variety of in situ studies. Furthermore, we discuss the application of hard X-ray microscopy to study defects in multi-crystalline solar

  15. Ratiometric Fluorescence Nanoprobes for Subcellular pH Imaging with a Single-Wavelength Excitation in Living Cells.

    PubMed

    Pan, Wei; Wang, Honghong; Yang, Limin; Yu, Zhengze; Li, Na; Tang, Bo

    2016-07-01

    Abnormal pH values in the organelles are closely associated with inappropriate cellular functions and many diseases. Monitoring subcellular pH values and their variations is significant in biological processes occurring in living cells and tissues. Herein, we develop a series of ratiometric fluorescence nanoprobes for quantification and imaging of pH values with a single-wavelength excitation in cytoplasm, lysosomes, and mitochondria. The nanoprobes consist of mesoporous silica nanoparticles assembled with aminofluorescein as the recognition unit for pH measurement and ethidium bromide as reference fluorophore. Further conjugation of subcellular targeting moiety enables the nanoprobes to specifically target lysosome and mitochondria. Confocal fluorescence imaging demonstrated that the nanoprobes could effectively monitor the pH fluctuations from 5.0 to 8.3 in living cells by ratio imaging with 488 nm excitation. Subcellular pH determination and imaging in lysosome and mitochondria could also be achieved in different conditions. The current method can offer a general strategy to determine subcellular analytes and investigate the interactions in biological samples. PMID:27295434

  16. A novel photoacoustic nanoprobe of ICG@PEG-Ag2S for atherosclerosis targeting and imaging in vivo.

    PubMed

    Wu, Chenxin; Zhang, Yejun; Li, Zhen; Li, Chunyan; Wang, Qiangbin

    2016-07-01

    Atherosclerosis is a major cause of cardiovascular and cerebrovascular diseases that have high mortality and disability rates. Because of its unclear pathogenic mechanism and heterogeneous distribution feature, it is still a big challenge to achieve precise diagnosis and therapy of atherosclerosis at its early stage in vivo. Herein, we fabricated a new ICG@PEG-Ag2S nanoprobe by a simple self-assembly of DT-Ag2S QDs, amphipathic C18/PEG polymer molecules and ICG. The ICG@PEG-Ag2S nanoprobe showed relatively long blood retention and was selectively accumulated in the region of atherosclerotic plaque due to the lipophilicity of the C18 chain to the atherosclerosis microenvironment, and thus the atherosclerosis was real-time monitored by high contrast-enhanced photoacoustic (PA) imaging of ICG. Combining the high signal-to-noise ratio (SNR) and high spatial resolution fluorescence imaging of Ag2S QDs in the second near-infrared window (NIR-II) and related histological assessment in vitro, the feasibility of this new nanoprobe for atherosclerosis targeting in an Apoe(-/-) mouse model was verified. Additionally, hemolysis and coagulation assays of the ICG@PEG-Ag2S revealed its decent hemocompatibility and no histological changes were observed in the main organs of the mouse. Such a simple, multifunctional nanoprobe for targeting and PA imaging of atherosclerosis will have a great potential for future clinical applications. PMID:26853187

  17. Amplified inhibition of the electrochemical signal of ferrocene by enzyme-functionalized graphene oxide nanoprobe for ultrasensitive immunoassay.

    PubMed

    Lai, Guosong; Cheng, Hui; Xin, Dinghong; Zhang, Haili; Yu, Aimin

    2016-01-01

    A nanoprobe-induced signal inhibition mechanism was designed for ultrasensitive electrochemical immunoassay at a chitosan-ferrocene (CS-Fc) based immunosensor. The nanoprobe was prepared by covalently loading signal antibody and high-content horseradish peroxidase (HRP) on the graphene oxide (GO) nanocarrier. The immunosensor was prepared through the stepwise assembly of gold nanoparticles (Au NPs) and capture antibody at a CS-Fc modified electrode. After sandwich immunoreaction, the GO-HRP nanoprobes were quantitatively captured onto the immunosensor surface and thus induced the production of a layer of insoluble film through the enzymatically catalytic reaction of the HRP labels. Both the dielectric immunocomplex formed on the immunosensor surface and the enzymatic precipitate with low electroconductivity led to the electrochemical signal decease of the Fc indicator, which was greatly amplified by the multi-enzyme signal amplification of the nanoprobe. Based on this amplified signal inhibition mechanism, a new ultrasensitive electrochemical immunoassay method was developed. Using carcinoembryonic antigen as a model analyte, this method showed a wide linear range over 5 orders of magnitude with a detection limit down to 0.54 pg/mL. Besides, the immunosensor showed good specificity, acceptable reproducibility and stability as well as satisfactory reliability for the serum sample analysis. PMID:26703270

  18. Construction of an upconversion nanoprobe with few-atom silver nanoclusters as the energy acceptor.

    PubMed

    Xiao, Yan; Zeng, Lingyu; Xia, Tian; Wu, Zhengjun; Liu, Zhihong

    2015-04-27

    Herein we report that few-atom silver nanoclusters (Ag NCs) can be effective energy acceptors for upconversion phosphors (UCPs). A luminescence resonance energy transfer (LRET) probe for biothiols was constructed by decorating UCPs with dithiol-stabilized Ag NCs. Owing to the unique properties of ultrasmall NCs, properties which bridge the gap between those of small molecules and those of nanoparticles, the use of approximately 1.9 nm Ag NCs as energy acceptors endows the probe with high energy-transfer efficiency, good biocompatibility, and flexibility. The UCP-Ag NC nanoprobe enables rapid and robust target assay in solutions. It was also uploaded into living cells and used to detect intracellular biothiol levels with high discrimination. Moreover, the probe shows transportability in vivo and can be used for tissue imaging. The facile growth of few-atom metal NCs on diverse templates may enable the development of various nanoprobes combining UCPs and metal NCs. PMID:25753304

  19. A value-added exopolysaccharide as a coating agent for MRI nanoprobes.

    PubMed

    Palma, Susana I C J; Rodrigues, Carlos A V; Carvalho, Alexandra; Morales, Maria del Puerto; Freitas, Filomena; Fernandes, Alexandra R; Cabral, Joaquim M S; Roque, Ana C A

    2015-09-14

    Fucopol, a fucose-containing exopolysaccharide (EPS) produced by the bacterium Enterobacter A47 DSM 23139 using glycerol as a carbon source, was employed as a new coating material for iron oxide magnetic nanoparticles (MNPs). The coated particles were assessed as nanoprobes for cell labeling by Magnetic Resonance Imaging (MRI). The MNPs were synthesized by a thermal decomposition method and transferred to an aqueous medium by a ligand-exchange reaction with meso-2,3-dimercaptosuccinic acid (DMSA). Covalent binding of EPS to DMSA-stabilized nanoparticles (MNP-DMSA) resulted in a hybrid magnetic-biopolymeric nanosystem (MNP-DMSA-EPS) with a hydrodynamic size of 170 nm, a negative surface charge under physiological conditions and transverse to longitudinal relaxivity ratio, r2/r1, of 148. In vitro studies with two human cell lines (colorectal carcinoma - HCT116 - and neural stem/progenitor cells - ReNcell VM) showed that EPS promotes internalization of nanoparticles in both cell lines. In vitro MRI cell phantoms showed a superior performance of MNP-DMSA-EPS in ReNcell VM, for which the iron dose-dependent MRI signal drop was obtained at relatively low iron concentrations (12-20 μg Fe per ml) and short incubation times. Furthermore, ReNcell VM multipotency was not affected by culture in the presence of MNP-DMSA or MNP-DMSA-EPS for 14 days. Our study suggests that Fucopol-coated MNPs represent useful cell labeling nanoprobes for MRI. PMID:26186402

  20. Multiple functional nanoprobe for contrast-enhanced bimodal cellular imaging and targeted therapy.

    PubMed

    Meng, Hong-Min; Lu, Limin; Zhao, Xu-Hua; Chen, Zhuo; Zhao, Zilong; Yang, Chan; Zhang, Xiao-Bing; Tan, Weihong

    2015-04-21

    Many one-photon fluorescence-based theranostic nanosystems have been developed for simultaneous therapeutic intervention/monitoring for various types of cancers. However, for early diagnosis of cancer, two-photon fluorescence microscopy (TPFM) can realize deep-tissue imaging with higher spatial resolution. In this study, we first report a multiple functional nanoprobe for contrast-enhanced bimodal cellular imaging and targeted therapy. Components of the nanoprobe include (1) two-photon dye-doped mesoporous silica nanoparticles (TPD-MSNs); (2) MnO2 nanosheets that act as a (i) gatekeeper for TPD-MSNs, (ii) quencher for TP fluorescence, and (iii) contrast agent for MRI; (3) cancer cell-targeting aptamers. Guided by aptamers, TPD-MSNs are rapidly internalized into the target cells. Next, intracellular glutathione reduces MnO2 to Mn(2+) ions, resulting in contrast-enhanced TP fluorescence and magnetic resonance signal for cellular imaging. Meanwhile, preloaded doxorubicin and Chlorin e6 are released for chemotherapy and photodynamic therapy, respectively, with a synergistic effect and significantly enhanced therapeutic efficacy. PMID:25791340

  1. Smart nanoprobes for ultrasensitive detection of breast cancer via magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Lee, Jaemin; Yang, Jaemoon; Seo, Sung-Baek; Ko, Hyun-Ju; Suh, Jin-Suck; Huh, Yong-Min; Haam, Seungjoo

    2008-12-01

    Antibody-conjugated hydrophilic magnetic nanocrystals for use as smart nanoprobes were developed for ultrasensitive detection of breast cancer via magnetic resonance (MR) imaging. MnFe2O4 nanocrystals (MNCs) for use as MR imaging contrast agents were synthesized by thermal decomposition to take advantage of their MR signal enhancement effect. The MNC surfaces were then modified with amphiphilic tri-block copolymers (dicarboxy poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)), not only allowing the MNCs to transfer from the organic to the aqueous phase, but also increasing the colloidal stability of the MNCs by masking poly(ethylene glycol). The physicochemical properties of the synthesized hydrophilic magnetic nanocrystals (HMNCs) were fully investigated. Trastuzumab (TZ), a monoclonal antibody against human epidermal growth factor receptor (HER2/neu), was further conjugated on the surface of HMNCs to specifically target HER2/neu over-expressed breast cancer cells. MR imaging analysis of target cells treated with TZ-conjugated HMNCs (TZ-HMNCs) clearly demonstrated their potential as high-performance nanoprobes for selective imaging.

  2. Active-target T1-weighted MR Imaging of Tiny Hepatic Tumor via RGD Modified Ultra-small Fe3O4 Nanoprobes

    PubMed Central

    Jia, Zhengyang; Song, Lina; Zang, Fengchao; Song, Jiacheng; Zhang, Wei; Yan, Changzhi; Xie, Jun; Ma, Zhanlong; Ma, Ming; Teng, Gaojun; Gu, Ning; Zhang, Yu

    2016-01-01

    Developing ultrasensitive contrast agents for the early detection of malignant tumors in liver is highly demanded. Constructing hepatic tumors specific targeting probes could provide more sensitive imaging information but still faces great challenges. Here we report a novel approach for the synthesis of ultra-small Fe3O4 nanoparticles conjugated with c(RGDyK) and their applications as active-target T1-weighted magnetic resonance imaging (MRI) contrast agent (T1-Fe3O4) for imaging tiny hepatic tumors in vivo. RGD-modified T1-Fe3O4 nanoprobes exhibited high r1 of 7.74 mM-1s-1 and ultralow r2/r1 of 2.8 at 3 T, reflecting their excellent T1 contrast effect at clinically relevant magnetic field. High targeting specificity together with favorable biocompatibility and strong ability to resist against non-specific uptake were evaluated through in vitro studies. Owing to the outstanding properties of tumor angiogenesis targeting with little phagocytosis in liver parenchyma, hepatic tumor as small as 2.2 mm was successfully detected via the T1 contrast enhancement of RGD-modified T1-Fe3O4. It is emphasized that this is the first report on active-target T1 imaging of hepatic tumors, which could not only significantly improve diagnostic sensitivity, but also provide post therapeutic assessments for patients with liver cancer. PMID:27570550

  3. Active-target T1-weighted MR Imaging of Tiny Hepatic Tumor via RGD Modified Ultra-small Fe3O4 Nanoprobes.

    PubMed

    Jia, Zhengyang; Song, Lina; Zang, Fengchao; Song, Jiacheng; Zhang, Wei; Yan, Changzhi; Xie, Jun; Ma, Zhanlong; Ma, Ming; Teng, Gaojun; Gu, Ning; Zhang, Yu

    2016-01-01

    Developing ultrasensitive contrast agents for the early detection of malignant tumors in liver is highly demanded. Constructing hepatic tumors specific targeting probes could provide more sensitive imaging information but still faces great challenges. Here we report a novel approach for the synthesis of ultra-small Fe3O4 nanoparticles conjugated with c(RGDyK) and their applications as active-target T1-weighted magnetic resonance imaging (MRI) contrast agent (T1-Fe3O4) for imaging tiny hepatic tumors in vivo. RGD-modified T1-Fe3O4 nanoprobes exhibited high r1 of 7.74 mM(-1)s(-1) and ultralow r2/r1 of 2.8 at 3 T, reflecting their excellent T1 contrast effect at clinically relevant magnetic field. High targeting specificity together with favorable biocompatibility and strong ability to resist against non-specific uptake were evaluated through in vitro studies. Owing to the outstanding properties of tumor angiogenesis targeting with little phagocytosis in liver parenchyma, hepatic tumor as small as 2.2 mm was successfully detected via the T1 contrast enhancement of RGD-modified T1-Fe3O4. It is emphasized that this is the first report on active-target T1 imaging of hepatic tumors, which could not only significantly improve diagnostic sensitivity, but also provide post therapeutic assessments for patients with liver cancer. PMID:27570550

  4. A value-added exopolysaccharide as a coating agent for MRI nanoprobes

    NASA Astrophysics Data System (ADS)

    Palma, Susana I. C. J.; Rodrigues, Carlos A. V.; Carvalho, Alexandra; Morales, Maria Del Puerto; Freitas, Filomena; Fernandes, Alexandra R.; Cabral, Joaquim M. S.; Roque, Ana C. A.

    2015-08-01

    Fucopol, a fucose-containing exopolysaccharide (EPS) produced by the bacterium Enterobacter A47 DSM 23139 using glycerol as a carbon source, was employed as a new coating material for iron oxide magnetic nanoparticles (MNPs). The coated particles were assessed as nanoprobes for cell labeling by Magnetic Resonance Imaging (MRI). The MNPs were synthesized by a thermal decomposition method and transferred to an aqueous medium by a ligand-exchange reaction with meso-2,3-dimercaptosuccinic acid (DMSA). Covalent binding of EPS to DMSA-stabilized nanoparticles (MNP-DMSA) resulted in a hybrid magnetic-biopolymeric nanosystem (MNP-DMSA-EPS) with a hydrodynamic size of 170 nm, a negative surface charge under physiological conditions and transverse to longitudinal relaxivity ratio, r2/r1, of 148. In vitro studies with two human cell lines (colorectal carcinoma - HCT116 - and neural stem/progenitor cells - ReNcell VM) showed that EPS promotes internalization of nanoparticles in both cell lines. In vitro MRI cell phantoms showed a superior performance of MNP-DMSA-EPS in ReNcell VM, for which the iron dose-dependent MRI signal drop was obtained at relatively low iron concentrations (12-20 μg Fe per ml) and short incubation times. Furthermore, ReNcell VM multipotency was not affected by culture in the presence of MNP-DMSA or MNP-DMSA-EPS for 14 days. Our study suggests that Fucopol-coated MNPs represent useful cell labeling nanoprobes for MRI.Fucopol, a fucose-containing exopolysaccharide (EPS) produced by the bacterium Enterobacter A47 DSM 23139 using glycerol as a carbon source, was employed as a new coating material for iron oxide magnetic nanoparticles (MNPs). The coated particles were assessed as nanoprobes for cell labeling by Magnetic Resonance Imaging (MRI). The MNPs were synthesized by a thermal decomposition method and transferred to an aqueous medium by a ligand-exchange reaction with meso-2,3-dimercaptosuccinic acid (DMSA). Covalent binding of EPS to DMSA

  5. Microgel photonics and lab on fiber technology for advanced label-free fiber optic nanoprobes

    NASA Astrophysics Data System (ADS)

    Giaquinto, M.; Micco, A.; Aliberti, A.; Ricciardi, A.; Ruvo, M.; Cutolo, A.; Cusano, A.

    2016-05-01

    We experimentally demonstrate a novel optical fiber label free optrode platform resulting from the integration between two rapidly emerging technologies such as Lab-on-Fiber Technology (LOFT) and Microgel Photonics (MPs). The device consists of a microgel (MG) layer painted on a metallic slabs supporting plasmonic resonances, directly integrated on the optical fiber tip. A molecular binding event induces significant changes in the MG layer thickness (and consequently in its 'equivalent' refractive index) resulting in an evident wavelength shift of the resonant feature. As a case of study, glucose-responsive MGs have been synthesized by incorporating into the gel matrix boronic acid moieties, whose interaction with glucose rules the driving forces for gel swelling. Our results pave the way for new technological routes aimed to develop advanced label free fiber optic nanoprobes.

  6. Development of an aptamer-conjugated fluorescent nanoprobe for MMP2

    NASA Astrophysics Data System (ADS)

    Han, Myoung-Eun; Baek, Sungmin; Kim, Hyun-Jung; Lee, Jung Hwan; Ryu, Sung-Ho; Oh, Sae-Ock

    2014-03-01

    Matrix metalloproteinase 2 (MMP2) plays critical roles in various diseases, such as atherosclerosis and cancer, and has been suggested to contribute to the instability of atherosclerotic plaque. To visualize MMP2 in pathologic tissues, we developed an aptamer targeting MMP2 protein by performing eight rounds of modified DNA systematic evolution of ligands by exponential enrichment (SELEX). The aptamer showed high affinity for MMP2 ( K d = 5.59 nM), precipitated MMP2, and detected MMP2 protein in pathological tissues such as atherosclerotic plaque and gastric cancer tissues. Furthermore, a MMP2 aptamer-conjugated fluorescent nanoprobe successfully visualized atherosclerotic plaques in apolipoprotein E (ApoE) knockout mice. These results suggest that the devised MMP2 aptamer could be useful for the development of various diagnostic tools.

  7. Development of an aptamer-conjugated fluorescent nanoprobe for MMP2

    PubMed Central

    2014-01-01

    Matrix metalloproteinase 2 (MMP2) plays critical roles in various diseases, such as atherosclerosis and cancer, and has been suggested to contribute to the instability of atherosclerotic plaque. To visualize MMP2 in pathologic tissues, we developed an aptamer targeting MMP2 protein by performing eight rounds of modified DNA systematic evolution of ligands by exponential enrichment (SELEX). The aptamer showed high affinity for MMP2 (Kd = 5.59 nM), precipitated MMP2, and detected MMP2 protein in pathological tissues such as atherosclerotic plaque and gastric cancer tissues. Furthermore, a MMP2 aptamer-conjugated fluorescent nanoprobe successfully visualized atherosclerotic plaques in apolipoprotein E (ApoE) knockout mice. These results suggest that the devised MMP2 aptamer could be useful for the development of various diagnostic tools. PMID:24589243

  8. Coherent Bragg nanodiffraction at the hard X-ray Nanoprobe beamline

    PubMed Central

    Hruszkewycz, S. O.; Holt, M. V.; Maser, J.; Murray, C. E.; Highland, M. J.; Folkman, C. M.; Fuoss, P. H.

    2014-01-01

    Bragg coherent diffraction with nanofocused hard X-ray beams provides unique opportunities for quantitative in situ studies of crystalline structure in nanoscale regions of complex materials and devices by a variety of diffraction-based techniques. In the case of coherent diffraction imaging, a major experimental challenge in using nanoscale coherent beams is maintaining a constant scattering volume such that coherent fringe visibility is maximized and maintained over the course of an exposure lasting several seconds. Here, we present coherent Bragg diffraction patterns measured from different nanostructured thin films at the Sector 26 Nanoprobe beamline at the Advanced Photon Source and demonstrate that with nanoscale positional control, coherent diffraction patterns can be measured with source-limited fringe visibilities more than 50% suitable for imaging by coherent Bragg ptychography techniques. PMID:24470418

  9. Highly sensitive ochratoxin A impedimetric aptasensor based on the immobilization of azido-aptamer onto electrografted binary film via click chemistry.

    PubMed

    Hayat, Akhtar; Sassolas, Audrey; Marty, Jean-Louis; Radi, Abd-Elgawad

    2013-01-15

    The aptamer immobilization onto organized mixed layers of diazonium salts via click chemistry was explored. The immobilized aptamer was employed in the fabrication of a highly sensitive and reusable electrochemical impedimetric aptasensor for the detection of ochratoxin A (OTA). The screen-printed carbon electrodes (SPCEs) were first modified by electrografting of a protected 4-((trimethylsilyl)ethynyl) benzene (TMSi-Eth-Ar) layer followed by a second one of p-nitrobenzene (p-NO(2)-Ar) by means of electrochemical reduction of their corresponding diazonium salts, (TMSi-Eth-Ar-N(2)(+)) and (p-NO(2)-ArN(2)(+)). After deprotection, a layer with active ethynyl groups was obtained. In the presence of copper (I) catalyst, the ethynyl groups reacted efficiently with aptamer bearing an azide function, thus forming a covalent 1,2,3-triazole linkage. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in the presence of ferri/ferrocyanide redox probe [Fe(CN)(6)](4-/3-) were used to characterize each step in the aptasensor development. The increase in electron-transfer resistance (R(et)) values due to the specific aptamer-OTA interaction was proportional to the concentration of OTA in a range between 1.25 ng/L and 500 ng/L, with a detection limit of 0.25 ng/L. PMID:23200352

  10. Microwave-assisted polyol synthesis of gadolinium-doped green luminescent carbon dots as a bimodal nanoprobe.

    PubMed

    Gong, Ningqiang; Wang, Hao; Li, Shuai; Deng, Yunlong; Chen, Xiao'ai; Ye, Ling; Gu, Wei

    2014-09-16

    The development of multimodal nanoprobes is highly desired in medical imaging because it integrates the advantages of multiple imaging modes. In this study, the gadolinium-doped green luminescent carbon dots (Gd-CDs) were prepared by the simple one-step microwave-assisted polyol method. The obtained Gd-CDs emitted a unique green photoluminescence with a quantum yield of 5.4%. The Gd-CDs exhibited a low cytotoxicity and could optically label the C6 glioma cells. Meanwhile, the r1 relaxivity of Gd-CDs was measured to be 11.356 mM(-1) s(-1). This high r1 value together with the r2/r1 ratio close to 1 nominates Gd-CDs as an excellent T1 contrast agent for magnetic resonance imaging. These Gd-CDs combining two complementary imaging modalities are therefore a promising bimodal nanoprobe in medical imaging for a better diagnosis. PMID:25157595

  11. Simultaneous Visualization of Multiple mRNAs and Matrix Metalloproteinases in Living Cells Using a Fluorescence Nanoprobe.

    PubMed

    Pan, Wei; Yang, Huijun; Li, Na; Yang, Limin; Tang, Bo

    2015-04-13

    Simultaneous monitoring of multiple tumour markers is of great significance for improving the accuracy of early cancer detection. In this study, a fluorescence nanoprobe has been prepared that can simultaneously monitor and visualize multiple mRNAs and matrix metalloproteinases (MMPs) in living cells. Confocal fluorescence imaging results indicate that the nanoprobe could effectively distinguish between cancer cells and normal cells even if one tumour maker of normal cells was overexpressed. Furthermore, it can detect changes in the expression levels of mRNAs and MMPs in living cells. The current approach could provide new tools for early cancer detection and monitoring the changes in expression levels of biomarkers during tumour progression. PMID:25752514

  12. A novel photoacoustic nanoprobe of ICG@PEG-Ag2S for atherosclerosis targeting and imaging in vivo

    NASA Astrophysics Data System (ADS)

    Wu, Chenxin; Zhang, Yejun; Li, Zhen; Li, Chunyan; Wang, Qiangbin

    2016-06-01

    Atherosclerosis is a major cause of cardiovascular and cerebrovascular diseases that have high mortality and disability rates. Because of its unclear pathogenic mechanism and heterogeneous distribution feature, it is still a big challenge to achieve precise diagnosis and therapy of atherosclerosis at its early stage in vivo. Herein, we fabricated a new ICG@PEG-Ag2S nanoprobe by a simple self-assembly of DT-Ag2S QDs, amphipathic C18/PEG polymer molecules and ICG. The ICG@PEG-Ag2S nanoprobe showed relatively long blood retention and was selectively accumulated in the region of atherosclerotic plaque due to the lipophilicity of the C18 chain to the atherosclerosis microenvironment, and thus the atherosclerosis was real-time monitored by high contrast-enhanced photoacoustic (PA) imaging of ICG. Combining the high signal-to-noise ratio (SNR) and high spatial resolution fluorescence imaging of Ag2S QDs in the second near-infrared window (NIR-II) and related histological assessment in vitro, the feasibility of this new nanoprobe for atherosclerosis targeting in an Apoe-/- mouse model was verified. Additionally, hemolysis and coagulation assays of the ICG@PEG-Ag2S revealed its decent hemocompatibility and no histological changes were observed in the main organs of the mouse. Such a simple, multifunctional nanoprobe for targeting and PA imaging of atherosclerosis will have a great potential for future clinical applications.Atherosclerosis is a major cause of cardiovascular and cerebrovascular diseases that have high mortality and disability rates. Because of its unclear pathogenic mechanism and heterogeneous distribution feature, it is still a big challenge to achieve precise diagnosis and therapy of atherosclerosis at its early stage in vivo. Herein, we fabricated a new ICG@PEG-Ag2S nanoprobe by a simple self-assembly of DT-Ag2S QDs, amphipathic C18/PEG polymer molecules and ICG. The ICG@PEG-Ag2S nanoprobe showed relatively long blood retention and was selectively

  13. Reagentless electrochemiluminescent detection of protein biomarker using graphene-based magnetic nanoprobes and poly-L-lysine as co-reactant.

    PubMed

    Liao, Ni; Zhuo, Ying; Chai, Ya-Qin; Xiang, Yun; Han, Jing; Yuan, Ruo

    2013-07-15

    This work described the construction of a reagentless and ultrasensitive electrochemiluminescence (ECL) immunosensor using poly-L-lysine as a co-reactant with Ru(bpy)3(2+) for signal amplification and magnetic Fe3O4 loaded graphene nanosheet as nanoprobes, which can achieve an impressive detection limit of 0.03 pg/mL human total 3,3',5-triiodothyronine (T3), a kind of diagnostic markers of thyroid disease. The bionanoprobes were prepared based on the coimmobilization of Ru(bpy)3(2+) and T3 detection antibody on the Fe3O4 loaded graphene nanosheet and the sensing interface was achieved by assembling T3 capture antibody on the gold nanoparticles (AuNPs) loaded electro-deposited L-lysine film modified bare glass carbon electrode (GCE). ECL responses were generated from the modified electrodes described above by just immersing them in phosphate buffer solutions (PBS) based on the sandwich-type immunoreactions. T3 was measured quantitatively in the range from 0.1 pg/mL to 10 ng/mL, which exhibits sufficiently high sensitivity and stability. The reagentless ECL immunoassay is a promising approach for the detection of a wide range of molecular analytes. PMID:23500362

  14. Long persistent near infrared luminescence nanoprobes LiGa5O8:Cr3+-PEG-OCH3 for in vivo imaging

    NASA Astrophysics Data System (ADS)

    Fu, Xiaoyan; Liu, Chunlin; Shi, Junpeng; Man, Huizi; Xu, Jia; Zhang, Hongwu

    2014-09-01

    The Cr3+-doped LiGa5O8 nanoparticles (LGNPs) with long-persistent near-infrared phosphorescence were obtained through a sol-gel approach followed by heat treatment at 800 °C in air. The obtained results reveal that the nanoparticles with an average diameter of 100 nm are well defined and have pure structure of LiGa5O8. After illumination for 3 min using a 254 nm UV lamp, the LGNPs exhibit strong near-infrared peak at ca. 720 nm belonging to tissue transparency window which can last for more than 1 h. Via surface modified with PEG-5000-OCH3, the LGNPs-PEG-OCH3 exhibit excellent biocompatibility and low toxicity. Under in vitro pre-excitation using a 254 nm UV lamp for 3 min, the in vivo distribution of the LGNPs-PEG-OCH3 in the abdomen can be detected in real time for more than 1 h. All the results indicate that the LGNPs-PEG-OCH3 can be used as potential nanoprobes to realize in vivo, real time and long time imaging with high sensitivity.

  15. New type of redox nanoprobe: C60-based nanomaterial and its application in electrochemical immunoassay for doping detection.

    PubMed

    Han, Jing; Zhuo, Ying; Chai, Ya-Qin; Xiang, Yun; Yuan, Ruo

    2015-02-01

    Carbon nanomaterials were usually exploited as nanocarriers in an electrochemical immunosensor but rarely acted as redox nanoprobes. Herein, our motivation is to adequately utilize the inner redox activity of fullerene (C60) to obtain a new type of redox nanoprobe based on a hydrophilic C60 nanomaterial. First, C60 nanoparticles (C60NPs) were prepared by phase-transfer method and functionalized with amino-terminated polyamidoamine (PAMAM) to obtain the PAMAM decorated C60NPs (PAMAM-C60NPs) which have better hydrophilicity compared to that of unmodified C60NPs and possesses abundant amine groups for further modification. Following that, gold nanoparticles (nano-Au) were absorbed on the PAMAM-C60NPs surface, and the resultant Au-PAMAM-C60NPs were employed as a new type of redox nanoprobe and nanocarrier to label detection antibodies (Ab2). Doping control has become the biggest problem facing international sport. Erythropoietin (EPO) as a blood doping agent has been a hotspot in doping control. After sandwich-type immunoreaction between EPO (as a model) and Ab2-labeled Au-PAMAM-C60NPs, the resultant immunosensor was further incubated with a drop of tetraoctylammonium bromide (TOAB) which acts as booster to arouse the inner redox activity of Au-PAMAM-C60NPs, thus a pair of reversible redox peaks is observed. As a result, the proposed immunosensor shows a wide linear range and a relatively low detection limit for EPO. This strategy paves a new avenue for exploring the redox nanoprobe based on carbon nanomaterials in the electrochemical biosensor field. PMID:25547661

  16. Organometallic nanoprobe to enhance optical response on the polycyclic aromatic hydrocarbon benzo[a]pyrene immunoassay using SERS technology.

    PubMed

    Dribek, Mohamed; Rinnert, Emmanuel; Colas, Florent; Crassous, Marie-Pierre; Thioune, Néné; David, Catalina; de la Chapelle, Marc; Compère, Chantal

    2014-08-12

    We demonstrated the use of a new organometallic nanoprobe for competitive surface-enhanced Raman scattering (SERS) immunoassay devoted to the detection of polycyclic aromatic hydrocarbons (PAH) such as benzo[a]pyrene (BaP) in seawater. The nanoprobes are gold nanoparticles (GNPs) labeled by a Raman reporter, the 5,5'-dithiobis(succinimidyl-2-nitrobenzoate) (DSNB) and functionalized with monoclonal antibodies anti-BaP. The antibodies are bound with a high specificity to the analyte while the GNPs enhanced the Raman scattering of the DSNB. This type of immunoassay involved the grafting of BaP onto a sensing surface. Thus, NH2-terminated self-assembled monolayer is formed on the surface of gold substrate using cysteamine. Amines finally reacted with 6-formylbenzo[a]pyrene. So, this SERS detection involves four steps: (i) the nanoprobes are incubated with the sample; (ii) a drop of the mixture is then put onto the substrate; (iii) the surface is rinsed; and (iv) the surface is analyzed by Raman spectroscopy. To synthesize the nanoprobes, firstly, we prepared GNPs according to Frens' method. Then, GNPs were spontaneously labeled by the DSNB Raman reporter, thanks to a strong gold-sulfur interaction. Thereafter, BaP antibodies were cross-linked to the DSNB labeled GNPs by reaction of proteins primary amino groups with N-hydroxyl succinimide (NHS). Before use in SERS detection, their activity was controlled by surface plasmon resonance technique. The present method allows us to detect BaP at trace concentration (2 nmol/L). The results demonstrate that the proposed method has a great potential for application in the monitoring of seawater. PMID:25109469

  17. Transferrin-targeted magnetic/fluorescence micelles as a specific bi-functional nanoprobe for imaging liver tumor

    NASA Astrophysics Data System (ADS)

    Qi, Hui; Li, Zhengzheng; Du, Kai; Mu, Ketao; Zhou, Qing; Liang, Shuyan; Zhu, Wenzhen; Yang, Xiangliang; Zhu, Yanhong

    2014-10-01

    In order to delineate the location of the tumor both before and during operation, we developed targeted bi-functional polymeric micelles for magnetic resonance (MR) and fluorescence imaging in liver tumors. Hydrophobic superparamagnetic iron oxide nanoparticles (SPIONs) were loaded into the polymeric micelles through self-assembly of an amphiphilic block copolymer poly(ethylene glycol)-poly(ɛ-caprolactone). After, transferrin (Tf) and near-infrared fluorescence molecule Cy5.5 were conjugated onto the surface of the polymeric micelles to obtain the nanosized probe SPIO@PEG- b-PCL-Tf/Cy5.5 (SPPTC). Imaging capabilities of this nanoprobe were evaluated both in vitro and in vivo. The accumulation of SPPTC in HepG2 cells increased over SPIO@PEG- b-PCL-Cy5.5 (SPPC) by confocal microscopy. The targeted nanoprobe SPPTC possessed favorable properties on the MR and fluorescence imaging both in vitro and in vivo. The MTT results showed that the nanoprobes were well tolerated. SPPTC had the potential for pre-operation evaluation and intra-operation navigation of tumors in clinic.

  18. A novel optical nanoprobe for trypsin detection and inhibitor screening based on Mn-doped ZnSe quantum dots.

    PubMed

    Gao, Xue; Tang, Guangchao; Li, Yang; Su, Xingguang

    2012-09-19

    In this paper, a novel optical nanoprobe (Mn:ZnSe d-dots-Arg(6)) for trypsin detection and its inhibitor screening has been constructed successfully based on the fluorescence quenching and recovery of Mn:ZnSe d-dots. Mn:ZnSe d-dots would aggregate in the presence of positively charged Arg(6) (six arginine residues) due to electrostatic interactions that result in the fluorescence quenching. Arg(6) can be hydrolyzed into small fragments in the presence of trypsin, and accordingly, the aggregation of Mn:ZnSe d-dots can be prohibited, which lead to the fluorescence recovery. Experimental results show that the recovery in fluorescence intensity is linearly proportional to the concentration of trypsin within the range of 0.1-12.0 μg mL(-1) with a detection limit of 40 ng mL(-1) under the optimized experimental conditions. We also prove the feasibility of fluorescence recovery of Mn:ZnSe d-dots for trypsin detection through the resonance light scattering (RLS) technique. Additionally, the optical nanoprobe can be employed for screening the inhibitors of trypsin. The optical nanoprobe was successfully applied for the determination of trypsin in human serum and urine samples with good accuracy and satisfactory recovery. PMID:22882833

  19. Transferrin-targeted magnetic/fluorescence micelles as a specific bi-functional nanoprobe for imaging liver tumor

    PubMed Central

    2014-01-01

    In order to delineate the location of the tumor both before and during operation, we developed targeted bi-functional polymeric micelles for magnetic resonance (MR) and fluorescence imaging in liver tumors. Hydrophobic superparamagnetic iron oxide nanoparticles (SPIONs) were loaded into the polymeric micelles through self-assembly of an amphiphilic block copolymer poly(ethylene glycol)-poly(ϵ-caprolactone). After, transferrin (Tf) and near-infrared fluorescence molecule Cy5.5 were conjugated onto the surface of the polymeric micelles to obtain the nanosized probe SPIO@PEG-b-PCL-Tf/Cy5.5 (SPPTC). Imaging capabilities of this nanoprobe were evaluated both in vitro and in vivo. The accumulation of SPPTC in HepG2 cells increased over SPIO@PEG-b-PCL-Cy5.5 (SPPC) by confocal microscopy. The targeted nanoprobe SPPTC possessed favorable properties on the MR and fluorescence imaging both in vitro and in vivo. The MTT results showed that the nanoprobes were well tolerated. SPPTC had the potential for pre-operation evaluation and intra-operation navigation of tumors in clinic. PMID:25400528

  20. New Insight of Tetraphenylethylene-based Raman Signatures for Targeted SERS Nanoprobe Construction Toward Prostate Cancer Cell Detection.

    PubMed

    Ramya, Adukkadan N; Joseph, Manu M; Nair, Jyothi B; Karunakaran, Varsha; Narayanan, Nisha; Maiti, Kaustabh Kumar

    2016-04-27

    We have designed and synthesized novel tetraphenylethylene (TPE) appended organic fluorogens and unfold their unique Raman fingerprinting reflected by surface-enhanced Raman scattering (SERS) upon adsorption on nanoroughened gold surface as a new insight in addition to their prevalent aggregation-induced emission (AIE) and aggregation-caused quenching (ACQ) phenomena. A series of five TPE analogues has been synthesized consisting of different electron donors such as (1) indoline with propyl (TPE-In), (2) indoline with lipoic acid (TPE-In-L), (3) indoline with Boc-protected propyl amine (TPE-In-Boc), (4) benzothaizole (TPE-B), and (5) quinaldine (TPE-Q). Interestingly, all five TPE analogues produced multiplexing Raman signal pattern, out of which TPE-In-Boc showed a significant increase in signal intensity in the fingerprint region. An efficient SERS nanoprobe has been constructed using gold nanoparticles as SERS substrate, and the TPE-In as the Raman reporter, which conjugated with a specific peptide substrate, Cys-Ser-Lys-Leu-Gln-OH, well-known for the recognition of prostate-specific antigen (PSA). The designated nanoprobe TPE-In-PSA@Au acted as SERS "ON/OFF" probe in peace with the vicinity of PSA protease, which distinctly recognizes PSA expression with a limit of detection of 0.5 ng in SERS platform. Furthermore, TPE-In-PSA@Au nanoprobe was efficiently recognized the overexpressed PSA in human LNCaP cells, which can be visualized through SERS spectral analysis and SERS mapping. PMID:27049934

  1. Detectability of Gravitational Waves from High-Redshift Binaries

    NASA Astrophysics Data System (ADS)

    Rosado, Pablo A.; Lasky, Paul D.; Thrane, Eric; Zhu, Xingjiang; Mandel, Ilya; Sesana, Alberto

    2016-03-01

    Recent nondetection of gravitational-wave backgrounds from pulsar timing arrays casts further uncertainty on the evolution of supermassive black hole binaries. We study the capabilities of current gravitational-wave observatories to detect individual binaries and demonstrate that, contrary to conventional wisdom, some are, in principle, detectable throughout the Universe. In particular, a binary with rest-frame mass ≳1010M⊙ can be detected by current timing arrays at arbitrarily high redshifts. The same claim will apply for less massive binaries with more sensitive future arrays. As a consequence, future searches for nanohertz gravitational waves could be expanded to target evolving high-redshift binaries. We calculate the maximum distance at which binaries can be observed with pulsar timing arrays and other detectors, properly accounting for redshift and using realistic binary waveforms.

  2. Detectability of Gravitational Waves from High-Redshift Binaries.

    PubMed

    Rosado, Pablo A; Lasky, Paul D; Thrane, Eric; Zhu, Xingjiang; Mandel, Ilya; Sesana, Alberto

    2016-03-11

    Recent nondetection of gravitational-wave backgrounds from pulsar timing arrays casts further uncertainty on the evolution of supermassive black hole binaries. We study the capabilities of current gravitational-wave observatories to detect individual binaries and demonstrate that, contrary to conventional wisdom, some are, in principle, detectable throughout the Universe. In particular, a binary with rest-frame mass ≳10^{10}M_{⊙} can be detected by current timing arrays at arbitrarily high redshifts. The same claim will apply for less massive binaries with more sensitive future arrays. As a consequence, future searches for nanohertz gravitational waves could be expanded to target evolving high-redshift binaries. We calculate the maximum distance at which binaries can be observed with pulsar timing arrays and other detectors, properly accounting for redshift and using realistic binary waveforms. PMID:27015470

  3. Search for Binary Trojans

    NASA Astrophysics Data System (ADS)

    Noll, Keith S.; Grundy, W. M.; Ryan, E. L.; Benecchi, S. D.

    2015-11-01

    We have reexamined 41 Trojan asteroids observed with the Hubble Space Telescope (HST) to search for unresolved binaries. We have identified one candidate binary with a separation of 53 milliarcsec, about the width of the diffraction limited point-spread function (PSF). Sub-resolution-element detection of binaries is possible with HST because of the high signal-to-noise ratio of the observations and the stability of the PSF. Identification and confirmation of binary Trojans is important because a Trojan Tour is one of five possible New Frontiers missions. A binary could constitute a potentially high value target because of the opportunity to study two objects and to test models of the primordial nature of binaries. The potential to derive mass-based physical information from the binary orbit could yield more clues to the origin of Trojans.

  4. Self-assembled mPEG-PCL-g-PEI micelles for multifunctional nanoprobes of doxorubicin delivery and magnetic resonance imaging and optical imaging.

    PubMed

    Guo, Qingfa; Kuang, Lei; Cao, Hui; Li, Weizhong; Wei, Jing

    2015-12-01

    In this paper, a novel bifunctional nanoprobe based on polyethylene glycol(MPEG)-poly(ϵ-caprolactone)(ϵ-CL)-polyethylenimine(PEI) labeled with FITC (MPEG-PCL-PEI-FITC, PCIF) were prepared to provide tumor therapy and simultaneous diagnostic information via magnetic resonance imaging (MRI) and optical imaging. Superparamagnetic iron oxide (SPIO) and doxorubicin (DOX) loaded PCIF (PCIF/SPIO/DOX) nanoprobes were prepared by self-assembling into micelles, which had uniformly distributed particle size of 130 ± 5 nm and a zeta potential of +35 ± 2 mV. Transmission electronic microscopy(TEM) showed that SPIO NPs were loaded into PCIF micelles. The PCIF/SPIO/DOX nanoprobes were superparamagnetic at 300 K with saturated magnetization of 20.5 emu/g Fe by vibrating-sample-magnetomete (VSM). Studies on cellular uptake of PCIF/SPIO/DOX nanoprobes demonstrated that SPIO NPs, DOX and FITC labeled MPEG-PCL-PEI were simultaneously taken up by the breast cancer (4T1) cells. After intravenous injection of PCIF/SPIO/DOX nanoprobes in 4T1 tumor-bearing mice, SPIO NPs, DOX and FITC labeled MPEG-PCL-PEI micelles were simultaneously delivered into tumor tissue by histochemisty. This work is important for the applications to multimodal diagnostic and theragnosis as nanomedicine. PMID:26513751

  5. PHOEBE: PHysics Of Eclipsing BinariEs

    NASA Astrophysics Data System (ADS)

    Prsa, Andrej; Matijevic, Gal; Latkovic, Olivera; Vilardell, Francesc; Wils, Patrick

    2011-06-01

    PHOEBE (PHysics Of Eclipsing BinariEs) is a modeling package for eclipsing binary stars, built on top of the widely used WD program (Wilson & Devinney 1971). This introductory paper overviews most important scientific extensions (incorporating observational spectra of eclipsing binaries into the solution-seeking process, extracting individual temperatures from observed color indices, main-sequence constraining and proper treatment of the reddening), numerical innovations (suggested improvements to WD's Differential Corrections method, the new Nelder & Mead's downhill Simplex method) and technical aspects (back-end scripter structure, graphical user interface). While PHOEBE retains 100% WD compatibility, its add-ons are a powerful way to enhance WD by encompassing even more physics and solution reliability.

  6. DNA-templated assembly of a heterobivalent quantum dot nanoprobe for extra- and intracellular dual-targeting and imaging of live cancer cells.

    PubMed

    Wei, Wei; He, Xuewen; Ma, Nan

    2014-05-26

    Quantum dots (QDs) hold great promise for the molecular imaging of cancer because of their superior optical properties. Although cell-surface biomarkers can be readily imaged with QDs, non-invasive live-cell imaging of critical intracellular cancer markers with QDs is a great challenge because of the difficulties in the automatic delivery of QD probes to the cytosol and the ambiguity of intracellular targeting signals. Herein, we report a new type of DNA-templated heterobivalent QD nanoprobes with the ability to target and image two spatially isolated cancer markers (nucleolin and mRNA) present on the cell surface and in the cell cytosol. Bypassing endolysosomal sequestration, this type of QD nanoprobes undergo macropinocytosis following the nucleolin targeting and then translocate to the cytosol for mRNA targeting. Fluorescence resonance energy transfer (FRET) based confocal microscopy enables unambiguous signal deconvolution of mRNA-targeted QD nanoprobes inside cancer cells. PMID:24740625

  7. Imaging PEG-like nanoprobes in tumor, transient ischemia, and inflammatory disease models.

    PubMed

    Wilks, Moses Q; Normandin, Marc D; Yuan, Hushan; Cho, Hoonsung; Guo, Yanyan; Herisson, Fanny; Ayata, Cenk; Wooten, Dustin W; El Fakhri, Georges; Josephson, Lee

    2015-06-17

    The iron chelator deferoxamine (DFO), approved for the treatment of iron overload, has been examined as a therapeutic in a variety of conditions which iron may exacerbate. To evaluate the potential of DFO-bearing PEG-like nanoprobes (DFO-PNs) as therapeutics, we determined their pharmacokinetics (PK) in normal mice, and imaged their accumulation in a tumor model and in models of transient brain ischemia and inflammation. DFO-PNs consist of a DFO, a Cy5.5, and PEG (5 kDa or 30 kDa) attached to Lys-Cys scaffold. Tumor uptake of a [(89)Zr]:DFO-PN(10) (30 kDa PEG, diameter 10 nm) was imaged by PET, surface fluorescence, and fluorescence microscopy. DFO-PN(10) was internalized by tumor cells (fluorescence microscopy) and by cultured cells (by FACS). [(89)Zr]:DFO-PN(4.3) (5 kDa PEG, diameter 4.3 nm) concentrated at incision generated inflammations but not at sites of transient brain ischemia. DFO-PNs are fluorescent, PK tunable forms of DFO that might be investigated as antitumor or anti-inflammatory agents. PMID:25971846

  8. Design for an X-ray Nanoprobe Prototype with a Sub-10-nm Positioning Requirement

    NASA Astrophysics Data System (ADS)

    Shu, D.; Maser, J.; Lai, B.; Vogt, S.

    2004-05-01

    We are developing a new hard x-ray nanoprobe beamline with 30 nm resolution at the Advanced Photon Source (APS). Imaging and spectroscopy at this resolution level require staging of x-ray optics and specimens with a mechanical repeatability of better than 10 nm. We have developed a prototype instrument with a novel interferometrically controlled scanning stage system. The system consists of nine DC-motor-driven stages, four picomotor-driven stages, and two PZT-driven stages. An APS-designed custom-built laser Doppler displacement meter system provides two-dimensional differential displacement measurement with subnanometer resolution between the zone-plate x-ray optics and the sample holder. Also included is the alignment and stable positioning of two stacked zone plates for increasing the focusing efficiency. The entire scanning system was designed with high stiffness, high repeatability, low drift, flexible scanning schemes, and possibility of fast feedback for differential motion. Designs of the scanning stage system, as well as preliminary mechanical test results, are presented in this paper.

  9. Fabrication and biological imaging application of AIE-active luminescent starch based nanoprobes.

    PubMed

    Liu, Meiying; Huang, Hongye; Wang, Ke; Xu, Dazhuang; Wan, Qing; Tian, Jianwen; Huang, Qiang; Deng, Fengjie; Zhang, Xiaoyong; Wei, Yen

    2016-05-20

    Fabrication of water dispersible, biocompatible and ultrabright luminescent polymeric nanoprobes (LPNs) has been the subject of great research interest. Although a number of LPNs have been fabricated previously through different strategies, the preparation of luminescent carbohydrate polymers with aggregation-induced emission (AIE) characterstic has received only limited attention. In this work, we reported for the first time that AIE-active luminescent starch can be facilely fabricated via mixing the aldehyde-contained AIE dye 4-(1,2,2-triphenylvinyl) benzaldehyde (TPE-CHO) with carboxyl methyl starch sodium (CMS) and amino phenylboronic acid in a one-pot procedure, in which aminophenylboronic acid can serve as the linkage for conjugation of TPE-CHO and CMS. The final products (TPE-CMS LPNs) were characterized by a number of characterization techniques such as (1)H nuclear magnetic resonance spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and fluorescence Spectroscopy in detail. To examine their biomedical application potential, the biocompatibility as well as cell uptake behavior of TPE-CMS LPNs were further determined. We demonstrated that TPE-CMS LPNs showed high water dispersibility and strong fluorescence, well biocompatibility and efficient cell internalization behavior, making them promising candidates for various biomedical applications. PMID:26917371

  10. Bifunctional electro-optical nanoprobe to real-time detect local biochemical processes in single cells.

    PubMed

    Zheng, Xin Ting; Hu, Weihua; Wang, Houxiao; Yang, Hongbin; Zhou, Wei; Li, Chang Ming

    2011-07-15

    A bifunctional electro-optical nanoprobe with integrated nanoring electrode and optical nanotip was fabricated and investigated to simultaneously detect both electrical and optical signals in real-time with high spatial resolution. Concurrent measurements of the oxidant generation and the intracellular antioxidant levels in single cells correlate the stronger oxidant generation with an altered initial antioxidant response in the breast cancer cells in comparison to the normal ones suggesting that the cell malignancy is associated with the strength of oxidative stress, and the higher antioxidant level may be the cause of the drug resistance. While the optical detection indicates the fluctuation of the intracellular redox homeostasis, the chronoamperometric signals allow quantitative real-time detection of the H₂O₂ release and decay. Furthermore, the nanoscale probe enables localized simultaneous detections thus discovering that activated enzymes responsible for the oxidative stress target at specific membrane regions. This method promises applications in study of the dynamics of important physiological processes, and provides the opportunity to unravel the interplay of various signaling pathways. PMID:21632233

  11. In situ deposition of Prussian blue on mesoporous carbon nanosphere for sensitive electrochemical immunoassay.

    PubMed

    Lai, Guosong; Zhang, Haili; Yu, Aimin; Ju, Huangxian

    2015-12-15

    A Prussian blue (PB) functionalized mesoporous carbon nanosphere (MCN) composite was prepared for loading signal antibody and high-content glucose oxidase (GOD) to obtain a new nanoprobe for sensitive electrochemical immunoassay. The MCN nanocarrier with an average diameter of 180 nm was synthesized by using mesoporous silica nanosphere as a hard template in combination with a hydrothermal carbonization method. This hydrophilic carbon nanomaterial provided an ideal platform for in situ deposition of high-content PB to form the MCN-PB nanocomposite. Based on the step-wise assembly of polyelectrolyte and gold nanoparticles (Au NPs) on the negative-charged nanocomposite, signal antibody and high-content GOD were loaded on this nanocarrier to obtain the nanoprobe. After a sandwich immunoreaction at an Au NPs-modified screen-printed carbon electrode based immunosensor, the nanoprobes were quantitatively captured on the electrode surface to produce sensitive electrochemical response with a PB-mediated GOD catalytic reaction for immunoassay. The high loading of PB and GOD on the nanoprobe greatly amplified the electrochemical signal, leading to the development of a new immunoassay method with high sensitivity. Using human immunoglobulin G as a model analyte, excellent analytical performance including a wide linear range from 0.01 to 100 ng/mL and a low detection limit down to 7.8 pg/mL was obtained. Additionally, the immunosensor showed high specificity, satisfactory stability and repeatability as well as acceptable reliability. The PB-mediated GOD electrochemical system well excluded the conventional interference from the dissolved oxygen. Thus this immunoassay method provides great potentials for practical applications. PMID:26201983

  12. Case A Binary Evolution

    SciTech Connect

    Nelson, C A; Eggleton, P P

    2001-03-28

    We undertake a comparison of observed Algol-type binaries with a library of computed Case A binary evolution tracks. The library consists of 5500 binary tracks with various values of initial primary mass M{sub 10}, mass ratio q{sub 0}, and period P{sub 0}, designed to sample the phase-space of Case A binaries in the range -0.10 {le} log M{sub 10} {le} 1.7. Each binary is evolved using a standard code with the assumption that both total mass and orbital angular momentum are conserved. This code follows the evolution of both stars until the point where contact or reverse mass transfer occurs. The resulting binary tracks show a rich variety of behavior which we sort into several subclasses of Case A and Case B. We present the results of this classification, the final mass ratio and the fraction of time spent in Roche Lobe overflow for each binary system. The conservative assumption under which we created this library is expected to hold for a broad range of binaries, where both components have spectra in the range G0 to B1 and luminosity class III - V. We gather a list of relatively well-determined observed hot Algol-type binaries meeting this criterion, as well as a list of cooler Algol-type binaries where we expect significant dynamo-driven mass loss and angular momentum loss. We fit each observed binary to our library of tracks using a {chi}{sup 2}-minimizing procedure. We find that the hot Algols display overall acceptable {chi}{sup 2}, confirming the conservative assumption, while the cool Algols show much less acceptable {chi}{sup 2} suggesting the need for more free parameters, such as mass and angular momentum loss.

  13. An Nd3+-sensitized upconversion nanophosphor modified with a cyanine dye for the ratiometric upconversion luminescence bioimaging of hypochlorite

    NASA Astrophysics Data System (ADS)

    Zou, Xianmei; Liu, Yi; Zhu, Xingjun; Chen, Min; Yao, Liming; Feng, Wei; Li, Fuyou

    2015-02-01

    Excessive or misplaced production of ClO- in living systems is usually associated with many human diseases. Therefore, it is of great importance to develop an effective and sensitive method to detect ClO- in living systems. Herein, we designed an 808 nm excited upconversion luminescence nanosystem, composed of the Nd3+-sensitized core-shell upconversion nanophosphor NaYF4:30%Yb,1%Nd,0.5%Er@NaYF4:20%Nd, which serves as an energy donor, and the ClO--responsive cyanine dye hCy3, which acts as an energy acceptor, for ratiometric upconversion luminescence (UCL) monitoring of ClO-. The detection limit of ClO- for this nanoprobe in aqueous solution is 27 ppb and the nanoprobe was successfully used to detect the ClO- in the living cells by ratiometric upconversion luminescence. Importantly, the nanoprobe realized the detection of ClO- in a mouse model of arthritis, which produced an excess of ROS, under 808 nm irradiation in vivo. The excitation laser efficiently reduced the heating effect, compared to the commonly used 980 nm laser for upconversion systems.Excessive or misplaced production of ClO- in living systems is usually associated with many human diseases. Therefore, it is of great importance to develop an effective and sensitive method to detect ClO- in living systems. Herein, we designed an 808 nm excited upconversion luminescence nanosystem, composed of the Nd3+-sensitized core-shell upconversion nanophosphor NaYF4:30%Yb,1%Nd,0.5%Er@NaYF4:20%Nd, which serves as an energy donor, and the ClO--responsive cyanine dye hCy3, which acts as an energy acceptor, for ratiometric upconversion luminescence (UCL) monitoring of ClO-. The detection limit of ClO- for this nanoprobe in aqueous solution is 27 ppb and the nanoprobe was successfully used to detect the ClO- in the living cells by ratiometric upconversion luminescence. Importantly, the nanoprobe realized the detection of ClO- in a mouse model of arthritis, which produced an excess of ROS, under 808 nm irradiation in

  14. Erythrocyte-derived nano-probes functionalized with antibodies for targeted near infrared fluorescence imaging of cancer cells

    PubMed Central

    Mac, Jenny T.; Nuñez, Vicente; Burns, Joshua M.; Guerrero, Yadir A.; Vullev, Valentine I.; Anvari, Bahman

    2016-01-01

    Constructs derived from mammalian cells are emerging as a new generation of nano-scale platforms for clinical imaging applications. Herein, we report successful engineering of hybrid nano-structures composed of erythrocyte-derived membranes doped with FDA-approved near infrared (NIR) chromophore, indocyanine green (ICG), and surface-functionalized with antibodies to achieve molecular targeting. We demonstrate that these constructs can be used for targeted imaging of cancer cells in vitro. These erythrocyte-derived optical nano-probes may provide a potential platform for clinical translation, and enable molecular imaging of cancer biomarkers. PMID:27446657

  15. Preliminary design of a zone plate based hard X-ray monochromatic diffraction nanoprobe for materials studies at APS

    NASA Astrophysics Data System (ADS)

    Cai, Zhonghou; Liu, Wenjun; Tischler, Jonathan Z.; Shu, Deming; Xu, Ruqing; Schmidt, Oliver

    2013-09-01

    Aiming at studies of the micro/nano-structures of a broad range materials and electronic devices, Advance Photon Source (APS) is developing a dedicated diffraction nanoprobe (DNP) beamline for the needs arising from a multidiscipline research community. As a part of the APS Upgrade Project, the planed facility, named Sub-micron 3-D Diffraction (S3DD) beamline1, integrates the K-B mirror based polychromatic Laue diffraction and the Fresnel zone-plate based monochromatic diffraction techniques that currently support 3D/2D microdiffraction programs at the 34-ID-E and 2-ID-D of the APS, respectively. Both diffraction nanoprobes are designed to have a 50-nm or better special resolution. The zone-plate based monochromatic DNP has been preliminarily designed and will be constructed at the sector 34-ID. It uses an APS-3.0-cm period or APS-3.3-cm period undulator, a liquid-nitrogen cooled mirror as its first optics, and a water cooled small gap silicon double-crystal monochromator with an energy range of 5-30 keV. A set of zone plates have been designed to optimize for focusing efficiency and the working distance based on the attainable beamline length and the beam coherence. To ensure the nanoprobe performance, high stiffness and high precision flexure stage systems have been designed or demonstrated for optics mounting and sample scanning, and high precision temperature control of the experimental station will be implemented to reduce thermal instability. Designed nanoprobe beamline has a good management on thermal power loading on optical components and allows high degree of the preservation of beam brilliance for high focal flux and coherence. Integrated with variety of X-ray techniques, planed facility provides nano-XRD capability with the maximum reciprocal space accessibility and allows micro/nano-spectroscopy studies with K-edge electron binding energies of most elements down to Vanadium in the periodic table. We will discuss the preliminary design of the zone

  16. Merging compact binaries in hierarchical triple systems: Resonant excitation of binary eccentricity

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Lai, Dong; Yuan, Ye-Fei

    2015-12-01

    We study the secular dynamics of compact binaries (consisting of white dwarfs, neutron stars or black holes) with tertiary companions in hierarchical triple systems. As the inner binary (with initially negligible eccentricity) undergoes orbital decay due to gravitational radiation, its eccentricity can be excited by gravitational forcing from the tertiary. This excitation occurs when the triple system passes through an "apsidal precession resonance," when the precession rate of the inner binary, driven by the gravitational perturbation of the external companion and general relativity, matches the precession rate of the outer binary. The eccentricity excitation requires the outer companion to be on an eccentric orbit, with the mutual inclination between the inner and outer orbits less than ˜40 ° . Gravitational wave (GW) signals from the inner binary can be significantly modified as the system evolves through the apsidal precession resonance. For some system parameters (e.g., a white dwarf binary with a brown dwarf tertiary), the resonance can happen when the binary emits GWs in the 10-4-10-1 Hz range (the sensitivity band of LISA).

  17. Detecting De-gelation through Tissue Using Magnetically Modulated Optical Nanoprobes (MagMOONs)

    PubMed Central

    Nguyen, KhanhVan T.; Anker, Jeffrey N.

    2014-01-01

    Alginate gels are widely used for drug delivery and implanted devices. The rate at which these gels break down is important for controlling drug release. Since the de-gelation may be different in vivo, monitoring this process in situ is essential. However, it is challenging to monitor the gel through tissue due to optical scattering and tissue autofluorescence. Herein we describe a method to detect through tissue the chemically-induced changes in viscosity and de-gelation process of alginate gels using magnetically modulated optical nanoprobes (MagMOONs). The MagMOONs are fluorescent magnetic microspheres coated with a thin layer of opaque metal on one hemisphere. The metal layer prevents excitation and emission light from passing through one side of the MagMOONs, which creates orientation-dependent fluorescence intensity. The magnetic particles also align in an external magnetic field and give blinking signals when they rotate to follow an external modulated magnetic field. The blinking signals from these MagMOONs are distinguished from background autofluorescence and can be tracked on a single particle level in the absence of tissue, or for an ensemble average of particles blinking through tissue. When these MagMOONs are dispersed in calcium alginate gel, they become sensors for detecting gel degradation upon addition of either ammonium ion or alginate lyase. Our results show MagMOONs start blinking approximately 10 minutes after 2 mg/mL alginate lyase addition and this blinking is clearly detected even through up to 4 mm chicken breast. This approach can potentially be employed to detect bacterial biofilm formation on medical implants by sensing specific proteases that either activate a related function or regulate biofilm formation. It can also be applied to other biosensors and drug delivery systems based on enzyme-catalyzed breakdown of gel components. PMID:26273129

  18. Nanoscopium: a Scanning Hard X-ray Nanoprobe Beamline at Synchrotron Soleil

    NASA Astrophysics Data System (ADS)

    Somogyi, A.; Polack, F.; Moreno, T.

    2010-06-01

    Nanoscopium is the single scanning hard X-ray nano-probe beamline planned at SOLEIL. This ˜155 m long beamline will fully exploit the high brilliance and coherence characteristics of the X-ray beam both for diffraction limited focusing and for contrast formation. It will offer the most advanced imaging techniques in multimodal mode and will be a research tool for a wide user community working in the fields of earth-, environmental-, and life-sciences. The different μ-μnano-probe techniques offered by the beamline will permit elemental mapping at trace (ppm) levels (scanning XRF), speciation mapping (XANES), phase gradient mapping (scanning differential phase contrast), and density-contrast based imaging of internal structures (coherent diffraction imaging) in the 30 nm to 1 μm spatial resolution range, also in "in situ conditions". Nanoscopium will cover the 5-20 keV energy range. The stability of the nanobeam will be ensured by horizontally reflecting beamline optics (a sagitally and a tangentially pre-focusing mirror, horizontally reflecting monochromators) in front of the overfilled secondary source. Trade-off between high energy resolution (ΔE/E˜10-4) and high flux (1011 ph/s with ΔE/E˜10-2) will be achieved by two interchangeable monochromators (a double crystal and a double multilayer one). KB mirror and FZP lenses will be used as focusing devices. The beamline is in the design and construction phase. It is foreseen to be open for users at the beginning of 2013.

  19. Rearranging a nanoprobe: Line foci, grid shadow patterns and performance tests

    NASA Astrophysics Data System (ADS)

    Rothermel, Martin; Butz, Tilman; Reinert, Tilo

    2009-06-01

    After a major modification of the target chamber at the Leipzig high energy ion nanoprobe the probe forming lens system, consisting of two separated quadrupole doublets, had been carefully realigned. This was done by adjusting the line foci position of each individual quadrupole on the centre position defined by the unfocused beam. Using a high magnification microscope the alignment process is very effective and precise. The lens system could be precisely realigned except an intrinsic rotational misalignment which is essentially reduced by a correction lens. Grid shadow patterns have been taken and analysed in order to assess the characteristics of the system. The dominant aberrations are spherical with an additional parasitic octupole. The grid shadow method is also very useful to determine the best position of the aperture diaphragms which minimizes the influence of the aberrations onto the beam spot size. The rearrangement allowed larger aperture diaphragms for higher beam currents at a moderate increase in beam spot sizes. Performance tests yielded proton microbeam currents and half-widths of 4.5 nA at 1.5 μm, 8.3 nA at 1.5 μm and 17.2 nA at 2 μm. For high resolution work the expected beam spots around 0.3 μm at 100 pA were not achieved. The reason is very likely interference on the beam scanner, correlated in x- and y-direction, which results from the insufficiently rectified power supply voltage of the transconductance amplifier.

  20. Template bank for gravitational waveforms from coalescing binary black holes: Nonspinning binaries

    SciTech Connect

    Ajith, P.; Hewitson, M.; Babak, S.; Chen, Y.; Krishnan, B.; Whelan, J. T.; Dorband, N.; Pollney, D.; Rezzolla, L.; Sintes, A. M.; Bruegmann, B.; Hannam, M.; Husa, S.; Sperhake, U.; Diener, P.; Gonzalez, J.; Santamaria, L.; Thornburg, J.

    2008-05-15

    Gravitational waveforms from the inspiral and ring-down stages of the binary black-hole coalescences can be modeled accurately by approximation/perturbation techniques in general relativity. Recent progress in numerical relativity has enabled us to model also the nonperturbative merger phase of the binary black-hole coalescence problem. This enables us to coherently search for all three stages of the coalescence of nonspinning binary black holes using a single template bank. Taking our motivation from these results, we propose a family of template waveforms which can model the inspiral, merger, and ring-down stages of the coalescence of nonspinning binary black holes that follow quasicircular inspiral. This two-dimensional template family is explicitly parametrized by the physical parameters of the binary. We show that the template family is not only effectual in detecting the signals from black-hole coalescences, but also faithful in estimating the parameters of the binary. We compare the sensitivity of a search (in the context of different ground-based interferometers) using all three stages of the black-hole coalescence with other template-based searches which look for individual stages separately. We find that the proposed search is significantly more sensitive than other template-based searches for a substantial mass range, potentially bringing about remarkable improvement in the event rate of ground-based interferometers. As part of this work, we also prescribe a general procedure to construct interpolated template banks using nonspinning black-hole waveforms produced by numerical relativity.

  1. Predicting binary merger event rates for advanced LIGO/Virgo

    NASA Astrophysics Data System (ADS)

    Holz, Daniel; Belczynski, Chris; O'Shaughnessy, Richard; Bulik, Tomek; LIGO Collaboration

    2016-03-01

    We discuss estimates of the rates of mergers of binary systems composed of neutron stars and/or stellar mass black holes. We use the StarTrack population synthesis code, and make predictions for the detection rate of compact binary coalescences with the advanced LIGO/Virgo gravitational wave detectors. Because these instruments are sensitive to massive (M > 20M⊙) stellar-mass binary black holes mergers out to high redshift (z > 1), we discuss the cosmological effects which must be taken into account when calculating LIGO detection rates, including a generalization of the calculation of the ``peanut factor'' and the sensitive time-volume.

  2. Persistent luminescence nanoprobe for biosensing and lifetime imaging of cell apoptosis via time-resolved fluorescence resonance energy transfer.

    PubMed

    Zhang, Lei; Lei, Jianping; Liu, Jintong; Ma, Fengjiao; Ju, Huangxian

    2015-10-01

    Time-resolved fluorescence technique can reduce the short-lived background luminescence and auto-fluorescence interference from cells and tissues by exerting the delay time between pulsed excitation light and signal acquisition. Here, we prepared persistent luminescence nanoparticles (PLNPs) to design a universal time-resolved fluorescence resonance energy transfer (TR-FRET) platform for biosensing, lifetime imaging of cell apoptosis and in situ lifetime quantification of intracellular caspase-3. Three kinds of PLNPs-based nanoprobes are assembled by covalently binding dye-labeled peptides or DNA to carboxyl-functionalized PLNPs for the efficient detection of caspase-3, microRNA and protein. The peptides-functionalized nanoprobe is also employed for fluorescence lifetime imaging to monitor cell apoptosis, which shows a dependence of cellular fluorescence lifetime on caspase-3 activity and thus leads to an in situ quantification method. This work provides a proof-of-concept for PLNPs-based TR-FRET analysis and demonstrates its potential in exploring dynamical information of life process. PMID:26232881

  3. Facile preparation and biological imaging of luminescent polymeric nanoprobes with aggregation-induced emission characteristics through Michael addition reaction.

    PubMed

    Lv, Qiulan; Wang, Ke; Xu, Dazhuang; Liu, Meiying; Wan, Qing; Huang, Hongye; Liang, Shangdong; Zhang, Xiaoyong; Wei, Yen

    2016-09-01

    Water dispersion aggregation-induced emission (AIE) dyes based nanomaterials have recently attracted increasing attention in the biomedical fields because of their unique optical properties, outstanding performance as imaging and therapeutic agents. The methods to conjugate hydrophilic polymers with AIE dyes to solve the hydrophobic nature of AIE dyes and makeS them widely used in biomedicine, which have been extensively explored and paid great effort previously. Although great advance has been made in the fabrication and biomedical applications of AIE-active polymeric nanoprobes, facile and efficient strategies for fabrication of biodegradable AIE-active nanoprobes are still high desirable. In this work, amphiphilic biodegradable fluorescent organic nanoparticles (PLL-TPE-O-E FONs) have been fabricated for the first time by conjugation of AIE dye tetraphenylethene acrylate (TPE-O-E) with Poly-l-Lysine (PLL) through a facile one-step Michael addition reaction, which was carried out under rather mild conditions, included air atmosphere, near room temperature and absent of metal catalysts or hazardous reagents. Due to the unique AIE properties, these amphiphilic copolymers tend to self-assemble into high luminescent water dispersible nanoparticles with size range from 400 to 600nm. Laser scanning microscope and cytotoxicity results revealed that PLL-TPE-O-E FONs can be internalized into cytoplasm with negative cytotoxicity, which implied that PLL-TPE-O-E FONs are promising for biological applications. PMID:27311129

  4. Analytical Study of BAM (Al/GaAs) and Photovoltaic Samples Using State-of-The-Art Auger Nanoprobes

    SciTech Connect

    Yadav, P.; Bouttemy, M.; Vigneron, J.; Etcheberry, A.; Martinez, E.; Renault, O.; Mur, P.; Chabli, A.; Munoz, D.

    2011-11-10

    For the analysis of certified semiconducting Al{sub 0.7}Ga{sub 0.3}As/GaAs superlattices and photovoltaic samples, we used new generations Auger nano-probes such as the JEOL JAMP-9500F Field emission Microprobe and the PHI-700 Xi system. These nano-probes are generally used for the chemical analysis of complex nano-structures at the deca-nanometric scale. In this paper, we first used both systems for the determination of the surface composition of an Al{sub 0.7}Ga{sub 0.3}As/GaAs reference sample. In that, we studied the impact of surface topography on the Auger analysis. Secondly, we used both systems for chemical analysis of photovoltaic samples. Here, we investigated the in-depth chemical composition, in particular the a-Si:H (n)/ZnO/Al and ITO/a-Si:H (p) interfaces, after a specific cross-section preparation. However, limitations such as image drift due to acoustic vibration and heating effects due to continuous bombardment of energetic electrons at the same point are still a big challenge for quick, routine analysis.

  5. Analytical Study of BAM (Al/GaAs) and Photovoltaic Samples Using State-of-The-Art Auger Nanoprobes

    NASA Astrophysics Data System (ADS)

    Yadav, P.; Bouttemy, M.; Martinez, E.; Vigneron, J.; Renault, O.; Mur, P.; Munoz, D.; Etcheberry, A.; Chabli, A.

    2011-11-01

    For the analysis of certified semiconducting Al0.7Ga0.3As/GaAs superlattices and photovoltaic samples, we used new generations Auger nano-probes such as the JEOL JAMP-9500F Field emission Microprobe and the PHI-700 Xi system. These nano-probes are generally used for the chemical analysis of complex nano-structures at the deca-nanometric scale. In this paper, we first used both systems for the determination of the surface composition of an Al0.7Ga0.3As/GaAs reference sample. In that, we studied the impact of surface topography on the Auger analysis. Secondly, we used both systems for chemical analysis of photovoltaic samples. Here, we investigated the in-depth chemical composition, in particular the a-Si:H (n)/ZnO/Al and ITO/a-Si:H (p) interfaces, after a specific cross-section preparation. However, limitations such as image drift due to acoustic vibration and heating effects due to continuous bombardment of energetic electrons at the same point are still a big challenge for quick, routine analysis.

  6. Application prospective of nanoprobes with MRI and FI dual-modality imaging on breast cancer stem cells in tumor.

    PubMed

    Chen, Hetao; Wang, Yu; Wang, Tong; Shi, Dongxing; Sun, Zengrong; Xia, Chunhui; Wang, Baiqi

    2016-01-01

    Breast cancer (BC) is a serious disease to threat lives of women. Numerous studies have proved that BC originates from cancer stem cells (CSCs). But at present, no one approach can quickly and simply identify breast cancer stem cells (BCSCs) in solid tumor. Nanotechnology is probably able to realize this goal. But in study process, scientists find it seems that nanomaterials with one modality, such as magnetic resonance imaging (MRI) or fluorescence imaging (FI), have their own advantages and drawbacks. They cannot meet practical requirements in clinic. The nanoprobe combined MRI with FI modality is a promising tool to accurately detect desired cells with low amount in tissue. In this work, we briefly describe the MRI and FI development history, analyze advantages and disadvantages of nanomaterials with single modality in cancer cell detection. Then the application development of nanomaterials with dual-modality in cancer field is discussed. Finally, the obstacles and prospective of dual-modal nanoparticles in detection field of BCSCs are also pointed out in order to speed up clinical applications of nanoprobes. PMID:27339420

  7. Patterned forest-assembly of single-wall carbon nanotubes and carbon nanotube atomic force microscopy nanoprobes

    NASA Astrophysics Data System (ADS)

    Wei, Haoyan

    Single-wall carbon nanotubes (SWNTs) are envisioned to greatly impact future science and technology particularly in the nanoscale range due to their unique one dimensional structure with tunable electrical conductivity. Thus they have received considerable attention in the development of nanodevices, field emitters and biosensors. The ability to place carbon nanotubes (CNTs) with controlled orientation at desired sites presents one major challenge in assembling these remarkable nanostructures into useful functional devices. In this dissertation a metal-assisted self-assembly technique was utilized in which dense rope-lattice-like SWNT forests with upright direction were obtained by immobilizing carboxylated nanotubes from dimethylformamide (DMF) nonaqueous media onto the underlying substrates with the linkage of FeO(OH)/FeOCl crystallites. In comparison with growing CNTs by chemical vapor deposition (CVD) on patterned catalyst pads, this self-assembly approach can take advantage of post-synthesis SWNT separation according to length and type (met allic versus semiconducting). Since FeO(OH)/FeOCl crystallites acted as linkers to bridge CNTs onto the substrates, the appropriate placement of these iron deposits was pivotal to realize the desired SWNT patterns. To assist in localizing these FeO(OH)/FeOCl crystallites, three approaches on diverse substrates including Nafion, Si/SiO x and Au were investigated with the aid of low-energy electron-beam direct writing (on Nafion and Si/SiOx) and photolithography (on Au) by creating preferential precipitation sites for FeO(OH)/FeOCl crystallites. Such differential deposition of FeO(OH)/FeOCl crystallites provided the basis for the patterned site-specific self-assembly of SWNT forests as demonstrated by atomic force microscopy (AFM) and resonance Raman spectroscopy. A second part of this dissertation resulted in CNT nanoprobes on conductive AFM probes fabricated with the help of a positive dielectrophoretic (DEP) process. Under

  8. In Vivo Immunotoxicity of SiO2@(Y0.5Gd0.45Eu0.05)2O3 as Dual-Modality Nanoprobes

    PubMed Central

    Tian, Xiumei; Li, Ermao; Yang, Fanwen; Peng, Ye; Zhu, Jixiang; He, Fupo; Chen, Xiaoming

    2014-01-01

    We have successfully synthesized SiO2@(Y0.5Gd0.45Eu0.05)2O3 nanocomposites as a potential dual-modality nanoprobe for molecular imaging in vitro. However, their immunotoxicity assessment in vivo remains unknown. In this article, the in vitro biocompatibility of our dual-modality nanoprobes was assayed in terms of cell viability and apoptosis. In vivo immunotoxicity was investigated by monitoring the generation of reactive oxygen species (ROS), cluster of differentiation (CD) markers and cytokines in Balb/c mice. The data show that the in vitro biocompatibility was satisfactory. In addition, the immunotoxicity data revealed there are no significant changes in the expression levels of CD11b and CD71 between the nanoprobe group and the Gd in a diethylenetriaminepentaacetic acid (DTPA) chelator (Gd-DTPA) group 24 h after injection in Balb/c mice (p > 0.05). Importantly, there are significant differences in the expression levels of CD206 and CD25 as well as the secretion of IL-4 and the generation of ROS 24 h after injection (p < 0.05). Transmission electron microscopy (TEM) images showed that few nanoprobes were localized in the phagosomes of liver and lung. In conclusion, the toxic effects of our nanoprobes may mainly result from the aggregation of particles in phagosomes. This accumulation may damage the microstructure of the cells and generate oxidative stress reactions that further stimulate the immune response. Therefore, it is important to evaluate the in vivo immunotoxicity of these rare earth-based biomaterials at the molecular level before molecular imaging in vivo. PMID:25105724

  9. Double Degenerate Binary Systems

    SciTech Connect

    Yakut, K.

    2011-09-21

    In this study, angular momentum loss via gravitational radiation in double degenerate binary (DDB)systems (NS + NS, NS + WD, WD + WD, and AM CVn) is studied. Energy loss by gravitational waves has been estimated for each type of systems.

  10. Binary synchronous simulator

    NASA Technical Reports Server (NTRS)

    Rogers, J. R., III

    1980-01-01

    Flexible simulator for trouble-shooting data transmission system uses binary synchronous communications protocol to produce error-free transmission of data between two points. Protocol may be used to replace display generator or be directly fed to display generator.