The Experts below are selected from a list of 19047 Experts worldwide ranked by ideXlab platform
Bert Hecht - One of the best experts on this subject based on the ideXlab platform.
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Fast quantitative Single-Molecule Detection at ultralow concentrations.
Analytical chemistry, 2010Co-Authors: Philippe Haas, Patrick Then, Andreas Wild, Wilfried Grange, Sylvain Zorman, Martin Hegner, Michel Calame, Ueli Aebi, Josef Flammer, Bert HechtAbstract:The applicability of Single-Molecule fluorescence assays in liquids is limited by diffusion to concentrations in the low picomolar range. Here, we demonstrate quantitative Single-Molecule Detection at attomolar concentrations within 1 min by excitation and Detection of fluorescence through a Single-mode optical fiber in presence of turbulent flow. The combination of high detectability and short measurement times promises applications in ultrasensitive assays, sensors, and point-of-care medical diagnostics.
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Quantitative Single-Molecule Detection at Ultralow Concentrations.
Analytical Chemistry, 2010Co-Authors: Philippe Haas, Patrick Then, Andreas Wild, Wilfried Grange, Sylvain Zorman, Martin Hegner, Michel Calame, Ueli Aebi, Josef Flammer, Bert HechtAbstract:The applicability of Single-Molecule fluorescence assays in liquids is limited by diffusion to concentrations in the low picomolar range. Here, we demonstrate quantitative Single-Molecule Detection at attomolar concentrations within 1 min by excitation and Detection of fluorescence through a Single-mode optical fiber in presence of turbulent flow. The combination of high detectability and short measurement times promises applications in ultrasensitive assays, sensors, and point-of-care medical diagnostics.
Qing Zhao - One of the best experts on this subject based on the ideXlab platform.
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Solid-state nanopore-based DNA Single Molecule Detection and sequencing
Microchimica Acta, 2015Co-Authors: Qing ZhaoAbstract:Nanopores have been used as ultrasensitive tools in sequencing of DNA, in RNA and protein conformation studies, diagnosis, drug screening, and in environmental monitoring. This review (with 128 refs.) summarizes recent progress on solid-state nanopore-based DNA Single-Molecule Detection and sequencing. Following a description of the principles of the technique, we focus on the fabrication of solid-state nanopores. We then treat the spatial and temporal resolution that can be accomplished with them in terms of DNA translocation and sequencing. Finally, we summarize novel methods for Detection such as tunneling current sensing and multichannel sensing, and then end up with a conclusion on developments and prospects of future nanopore technology.
Jixin Cheng - One of the best experts on this subject based on the ideXlab platform.
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Plasmon-enhanced stimulated Raman scattering microscopy with Single-Molecule Detection sensitivity.
Nature communications, 2019Co-Authors: Cheng Zong, Ranjith Premasiri, Haonan Lin, Yimin Huang, Chi Zhang, C Yang, Bin Ren, L D Ziegler, Jixin ChengAbstract:Stimulated Raman scattering (SRS) microscopy allows for high-speed label-free chemical imaging of biomedical systems. The imaging sensitivity of SRS microscopy is limited to ~10 mM for endogenous bioMolecules. Electronic pre-resonant SRS allows Detection of sub-micromolar chromophores. However, label-free SRS Detection of Single bioMolecules having extremely small Raman cross-sections (~10−30 cm2 sr−1) remains unreachable. Here, we demonstrate plasmon-enhanced stimulated Raman scattering (PESRS) microscopy with Single-Molecule Detection sensitivity. Incorporating pico-Joule laser excitation, background subtraction, and a denoising algorithm, we obtain robust Single-pixel SRS spectra exhibiting Single-Molecule events, verified by using two isotopologues of adenine and further confirmed by digital blinking and bleaching in the temporal domain. To demonstrate the capability of PESRS for biological applications, we utilize PESRS to map adenine released from bacteria due to starvation stress. PESRS microscopy holds the promise for ultrasensitive Detection and rapid mapping of molecular events in chemical and biomedical systems. Stimulated Raman scattering (SRS) microscopy enables label-free chemical imaging at high speed, but has been limited by low sensitivity. Here, the authors demonstrate plasmon-enhanced SRS microscopy and achieve Single Molecule Detection sensitivity.
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plasmon enhanced stimulated raman scattering microscopy with Single Molecule Detection sensitivity
arXiv: Optics, 2019Co-Authors: Cheng Zong, Ranjith Premasiri, Haonan Lin, Yimin Huang, Chi Zhang, C Yang, Bin Ren, L D Ziegler, Jixin ChengAbstract:Stimulated Raman scattering (SRS) microscopy allows for high-speed label-free chemical imaging of biomedical systems. The imaging sensitivity of SRS microscopy is limited to ~10 mM for endogenous bioMolecules. Electronic pre-resonant SRS allows Detection of sub-micromolar chromophores. However, label-free SRS Detection of Single bioMolecules having extremely small Raman cross-sections (~10-30 cm2 sr-1) remains unreachable. Here, we demonstrate plasmon-enhanced stimulated Raman scattering (PESRS) microscopy with Single-Molecule Detection sensitivity. Incorporating pico-Joule laser excitation, background subtraction, and a denoising algorithm, we obtained robust Single-pixel SRS spectra exhibiting the statistics of Single-Molecule events. Single-Molecule Detection was verified by using two isotopologues of adenine. We further demonstrated the capability of applying PESRS for biological applications and utilized PESRS to map adenine released from bacteria due to starvation stress. PESRS microscopy holds the promise for ultrasensitive Detection of molecular events in chemical and biomedical systems.
Younan Xia - One of the best experts on this subject based on the ideXlab platform.
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Controlling the Synthesis and Assembly of Silver Nanocrystals for Single-Molecule Detection by SERS
Micro- and Nanotechnology Sensors Systems and Applications IV, 2012Co-Authors: Christine H. Moran, Younan XiaAbstract:ABSTRACT Detecting toxic chemical or biological ag ents in low concentrations requires a hi ghly specific sensing technique, such as surface-enhanced Raman spectroscopy (SERS). The controlled synthesis of metallic nanocrystals has provided a new class of substrates for more reliable and sensitive SERS applications. The nanocrystal shape plays a major role in designing SERS substrates for maximizing the SERS enhancement factor (EF). Assembling nanocrystals into dimers can further amplify the EF, opening the door to the possibility of Single-Molecule Detection. Here, we briefly discuss our recent work on the synthesis of s ilver (Ag) nanocrystals and their assembly in to dimers and other reliable techniques to form hot spots with sufficiently high EF for Single-Molecule Detection by SERS. Keywords: silver nanocrystals, surface-enhanced Raman spectroscopy, Single-Molecule Detection, dimers, plasmon resonance 1. INTRODUCTION Single-Molecule (SM) Detection is the ultimate goal of many sensing techniques. It is extremely difficult to detect an analyte at a Single-Molecule level because its signals are typi cally weak and often obscured by the background noise. In recent years, the use of surface-enhanced Raman spectroscopy (SERS) has made in credible progress toward the Detection of Single Molecules due to two factors.
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Metal nanoparticles with gain toward Single-Molecule Detection by surface-enhanced Raman scattering.
Nano letters, 2010Co-Authors: Younan XiaAbstract:Single-Molecule Detection via surface-enhanced Raman scattering (SERS) has raised great interest over the past decade. The usual approach toward this goal is to harness the strong surface plasmon resonance of light with complex metallic nanostructures, such as particle aggregates, two-particle gaps, sharp tips, or particles with sharp apexes. Here we propose another route toward the goal by introducing gain medium into Single metal nanoparticles with simple geometry. Our calculations show that cubic gold nanobox particles that contain a gain material within the core can create an extremely high enhancement factor of local field intensity larger than 108 and a SERS enhancement factor on the order of 1016−1017.
Meni Wanunu - One of the best experts on this subject based on the ideXlab platform.
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Plasmonic Nanopores for Single-Molecule Detection and Manipulation: Toward Sequencing Applications.
Nano letters, 2019Co-Authors: Denis Garoli, Hirohito Yamazaki, Nicolò Maccaferri, Meni WanunuAbstract:Solid-state nanopore-based sensors are promising platforms for next-generation sequencing technologies, featuring label-free Single-Molecule sensitivity, rapid Detection, and low-cost manufacturing. In recent years, solid-state nanopores have been explored due to their miscellaneous fabrication methods and their use in a wide range of sensing applications. Here, we highlight a novel family of solid-state nanopores which have recently appeared, namely plasmonic nanopores. The use of plasmonic nanopores to engineer electromagnetic fields around a nanopore sensor allows for enhanced optical spectroscopies, local control over temperature, thermophoresis of Molecules and ions to/from the sensor, and trapping of entities. This Mini Review offers a comprehensive understanding of the current state-of-the-art plasmonic nanopores for Single-Molecule Detection and biomolecular sequencing applications and discusses the latest advances and future perspectives on plasmonic nanopore-based technologies.
