851 results about "Surface-enhanced Raman spectroscopy" patented technology

Surface-enhanced Raman spectroscopy (SERS) uses nanoscale metal particles (SERS-active particles) or surface roughness to enhance the Raman signal of Raman-active analytes contacting the surface. SERS sandwich particles contain SERS-active particles sandwiching a Raman-active substance and serve as optical tags. Preferably, the particles are rod-shaped, with each layer (SERS-active and Raman-active) formed as a distinct stripe of the particle. These freestanding particles can be derivatized with surface ligands capable of associating with analytes of interest in, for example, a biological sample. The acquired Raman spectrum of the particle encodes the identity of the ligand. Because of the simplicity and intensity of Raman spectra, highly multiplexed assays are capable using SERS particles with different Raman-active species.

Provided according to embodiments of the invention are nanostructured surfaces that include a substrate; and an array of metallic nanopillar islands on the substrate, wherein each metallic nanopillar island includes a metal base layer on the substrate and a plurality of metallic nanopillars on the metal base layer, and wherein portions of the substrate between adjacent metallic nanopillar islands are free of the metal base layer. Also provided according to some embodiments of the invention are nanostructured surfaces that include a non-conductive substrate; and at least one nanoelectrode defined within the non-conductive substrate, wherein the at least one nanoelectrode is sized and/or shaped to immobilize an analyte or a probe molecule. Also provided are apparatuses and methods for SERS and detection of analytes or biological binding by EDL capacitance.

An improved substrate for Raman spectroscopy of an analyte comprises a porous metal film. Enhancement factors and uniformity of the substrate can be enhanced by electrochemical roughening of the film. Improved sensors and spectrometers using such substrates are also described.

Disclosed herein are diagnostic assays using surface enhanced Raman spectroscopy (SERS)-active particles, including liquid-based assays; magnetic capture assays; microparticle-nanoparticle satellite structures for signal amplification in an assay; composite SERS-active particles useful for enhanced detection of targets; and sample tubes and processes for using the same.

Surface-enhanced spectroscopy, such as surface-enhanced Raman spectroscopy employs aggregates that are of a size that allows easy handling. The aggregates are generally at least about 500 nm in dimension. The aggregates can be made of metal particles of size less than 100 nm, allowing enhanced spectroscopic techniques that operate at high sensitivity. This allows the use of larger, easily-handleable aggregates. Signals are determined that are caused by single analytes adsorbed to single aggregates, or single analytes adsorbed on a surface. The single analytes can be DNA or RNA fragments comprising at least one base.

Integrated radiation source/amplifying structures for use in surface enhanced Raman spectroscopy (SERS) and hyper-SERS are disclosed. The structures include a radiation source integrated with a SERS-active structure that is provided within a resonant cavity. SERS and hyper-SERS systems employing the integrated radiation source/amplifying structures are disclosed. Methods of performing SERS and hyper-SERS are also disclosed.

A nano-fluidic trapping device and method of fabrication are disclosed. In one embodiment, a nano-fluidic trapping device for assembling a SERS-active cluster includes a substrate. The nano-fluidic trapping device further includes a SERS-active cluster compartment. The SERS-active cluster is formed in the SERS-active cluster compartment. In addition, the nano-fluidic trapping device includes a reservoir. The reservoir allows introduction of target molecules into the nano-fluidic trapping device. Moreover, the nano-fluidic trapping device includes a microchannel. The microchannel allows the target molecules to be introduced to the SERS-active cluster compartment from the reservoir. The nano-fluidic trapping device also includes a nanochannel. The SERS-active cluster compartment, the reservoir, the microchannel, and the nanochannel are disposed within the substrate.

This invention relates to methods of preparing substrates that enhance the Raman signal of analytes in surface-enhanced Raman spectroscopy (SERS). The SERS-active substrate comprises an array of metal nanoparticles at least partially embedded in a template. The substrate's uniform and readily reproducible SERS-active properties with a wide range of analyte concentrations substantially enhance the power and utility of SERS. This invention also provides sensors, as well as Raman instruments, comprising the SERS-active substrates.

The present invention is related in general to chemical and biological detection and identification and more particularly to systems and methods for the rapid detection and identification of low concentrations of chemicals and biomaterials using surface enhanced Raman spectroscopy.

An inventive sensor is used in combination with spectroscopic techniques to detect, identify and quantify ultratrace (ppt to ppb) quantities of analytes in air or water samples. The sensor preferably comprises a photonic crystal fiber having an air hole cladding with functionalized air holes. Surface-enhanced Raman spectroscopy is a preferred spectroscopic technique. In such applications, the air holes of the fiber may be functionalized by adsorbing a self-assembled monolayer on their inner surfaces, and immobilizing metallic nanoparticles to the monolayer. The invention has chemical and biomedical applications, and utility in detecting chemical and biological agents used in warfare.

The invention relates to a method for selectively preparing or integrating multistage silver micro-nanostructures inside various plane substrates and micro fluidic chip channels by the utilization of the femtosecond laser inducing metallic silver reduction technology. In addition, the silver multistage micro-nanostructure substrate prepared by the method is used as a reinforced substrate for surface-enhanced raman spectroscopy SERS. The method provided by the invention comprises the following steps of: preparing a silver plating solution for femtosecond laser micro-nano machining, establishing a femtosecond laser micro-nano machining system for realizing multi-point scan in the silver plating solution, placing the silver plating solution and the substrate into the femtosecond laser micro-nano machining system and preparing the multistage silver micro-nanostructures on the substrate. According to the invention, a laser beam scans in the silver plating solution along a track designed in advance by a program. The preparation method is independent of the smoothness of the substrate. In particular, the preparation of silver multistage structure SERS substrate can be accomplished on the bottom of the micro fluidic chip channels, thus realizing catalysis and surface-enhanced raman test application.

The invention discloses a manufacturing method of a tunable triangular metal nano particle array structure. The method comprises the following steps: (1) selecting a substrate with a suitable model according to the requirement of transmission wavelength, and carrying out cleaning and hydrophiling treatment on the substrate; (2) evenly self-assembling a layer of nano spheres on the surface of the substrate; (3) etching the manufactured self-assembling nano sphere layer by using a reaction ion etcher (RIE) process to change the size of gaps between adjacent nano spheres; (4) self-assembling etched nano spheres to serve as a mould, and filling metals in gaps between adjacent nano spheres; and (5) removing the nano sphere self-assembling layer by using a Lift off process to obtain an array chip in a metal nano structure. The manufactured chip in the metal nano structure has controllable optical property, can be applied to fields such as local surface plasma resonance (LSPR) sensing, surface enhanced Raman spectroscopy (SERS) and the like, and can realize rapid detection of biologic and chemical molecules.

Metal nanoparticles associated with a spectroscopy-active (e.g., Raman-active) analyte and surrounded by an encapsulant are useful as sensitive optical tags detectable by surface-enhanced spectroscopy (e.g., surface-enhanced Raman spectroscopy).

Surface-enhanced Raman spectroscopic (SERS) systems and methods for detecting biomolecules of interest, such as a virus, bacterium, or other infectious agent, are provided. A spectroscopic assay based on surface enhanced Raman scattering (SERS) using a silver nanorod array substrate fabricated by oblique angle deposition has been developed that allows for rapid detection of trace levels of viruses or bacteria with a high degree of sensitivity and specificity. This novel and improved SERS assay can detect minor spectral differences within strains of a single virus type such as respiratory syncytial virus or influenza virus in the presence of biological media. The method provides rapid diagnostics for direct molecular and structural characterization of virus strains and virus gene deletion mutants generating reproducible viral spectra without viral manipulation.

Provided herein is a reusable nano-imaging probe useful in surface enhanced Raman spectroscopic (SERS) applications demonstrating nanometer scale resolution. The nano-imaging probe generally comprises a fiber optic imaging bundle of fiber optic elements each having a tapered etched end and a non-tapered non-etched end. The tapered etched ends further comprise a SERS-active metal substrate deposited thereon effective to create a uniform SERS enhancement for an analyte or other substance of interest. Also provided is a SERS nanoimager for dynamic chemical imaging using the nano-imaging probe and methods of imaging and Raman spectral analysis and identification using the nano-imaging probe.

A surface-enhanced Raman spectroscopy (SERS) substrate formed from a plurality of monolayers of polyhedral silver nanocrystals, wherein at least one of the monolayers has polyvinypyrrolidone (PVP) on its surface, and thereby configured for sensing arsenic is described. Highly active SERS substrates are formed by assembling high density monolayers of differently shaped silver nanocrystals onto a solid support. SERS detection is performed directly on this substrate by placing a droplet of the analyte solution onto the nanocrystal monolayer. Adsorbed polymer, polyvinypyrrolidone (PVP), on the surface of the nanoparticles facilitates the binding of both arsenate and arsenite near the silver surface, allowing for highly accurate and sensitive detection capabilities.

A surface enhanced Raman spectroscopy (SERS) analytical device includes a substrate having a porous structure, and a plurality of plasmonic nanoparticles embedding in the porous structure and forming a sensing region. A method of detecting a target analyte in a sample includes contacting the sample with the substrate, whereby the target analyte, if present in the sample, is concentrated in the sensing matrix. The substrate may then be analyzed using SERS detection equipment.

A surface-enhanced Raman spectroscopy (SERS)—active structure for use in Raman scattering detection has an array of nanostructures formed on a substrate by deposition and chemical etching. The nanostructures are coated with metal nanoparticles.

The methods and apparatus disclosed herein are useful for detecting nucleotides, nucleosides, and bases and for nucleic acid sequence determination. The methods involve detection of a nucleotide, nucleoside, or base using surface enhanced Raman spectroscopy (SERS). The detection can be part of a nucleic acid sequencing reaction to detect uptake of a deoxynucleotide triphosphate during a nucleic acid polymerization reaction, such as a nucleic acid sequencing reaction. The nucleic acid sequence of a synthesized nascent strand, and the complementary sequence of the template strand, can be determined by tracking the order of incorporation of nucleotides during the polymerization reaction.

The invention relates to a spectral method capable of exciting surface-enhanced Raman spectroscopy (SERS) in a long range surface plasmon mode. The method comprises the following steps of: constructing a buffer layer, a metal layer and a protective layer on the bottom surface of a prism to form a long range surface plasmon resonance (LRSPR) device; placing the LRSPR device with multilayer structure under the irradiation of a laser source, and adjusting the incident angle of the laser source to an LRSPR angle; and in a specific incident direction, generating the LRSPR, so that the electric magnetic field on the surface of a metal is enhanced, and the excitation process of the surface-enhanced Raman spectroscopy of a detected object of a deeper area in a sample layer is completed. Because the long range effect has deeper penetrating effect, the construction of the protective layer on the surface of the metal layer becomes possible. The transduction membrane made of chemically inert gold or platinum is changed into a silver membrane with lower cost, oxidation resistance and better enhancing effect. The LRSPR-mechanism-based SERS detection method has great significance.