36results about How to "Enhanced SERS signal" patented technology

The invention relates to a gold nanoparticle-molybdenum disulfide-gold ultra-sensitive SERS substrate material and a preparation method thereof. The structure is a gold nanoparticle/molybdenum disulfide/gold sandwich structure with the gold nanoparticle as a core, the molybdenum disulfide as a shell, and a layer of gold particles with a certain "hot sopt" effects evaporated on the surface of the core-shell structure in a vacuum mode. The molar ratio of the nano-material element is molybdenum: sulfur: gold being 1.0:1.9: 1.0. The chemical formula of molybdenum disulfide is MoS2. Compared with the prior art, the preparation method of the gold nanoparticle-molybdenum disulfide-gold ultra-sensitive SERS substrate material is convenient and fast. According to the gold nanoparticle-molybdenum disulfide-gold SERS substrate material, MoS2 serves as a supporting body to adsorb target molecules, a double-plasma coupling effect exists between the Au nano particles, the "hot spot" effect enhancedan SERS signal, the MoS2 is in bridge connection with the Au so as to realize the ultra-sensitive detection of rhodamine B molecules, the detection limit can reach 10-10 mol/L, and the repeatability and the stability of the rhodamine B is detected to be good.

The invention discloses a preparation method and an application of a SERS biosensor for detecting a tumor marker miRNA 141. The method comprises the following steps: (1) combining a Fe3O4@Au magneticnanoparticle with a capture probe to obtain a capture unit solution; (2) combining a hollow gold nanosphere with an initiation probe to prepare a signal unit solution; and (3) reacting and combining acapture unit, miRNA 141 and a signal unit, and performing magnetic separation to obtain the SERS biosensor. The application is characterized in that an SERS signal is detected by a Raman spectrometer, SERS signal intensities corresponding to a series of miRNA-141 with different concentrations are detected, and a quantitative relationship between the concentration of the miRNA-141 and the SERS signal intensity is established; and the concentration of miRNA-141 in an unknown sample is detected according to the quantitative relationship. The SERS biosensor has the advantages of high sensitivity,high specificity, simple assembling process and fast detection speed.

The invention discloses a phenol recognition SERS probe, a preparation and an application thereof, and a universal ultra-sensitive immunoassay method based on SERS. Firstly, a phenol responsive SERS probe is prepared by reducing chloroauric acid with DTDBA, ahen, ELISA is combined with SERS, biomolecules are labeled with ALP, a substrate PPNA is hydrolyzed by ALP to generate phenol. An SERS probesignal caused by the phenol is used for realizing a technology for sensitive detection of the biomolecules. The technology can not only overcome the disadvantages of low sensitivity of the conventional enzyme linked immunosorbent assay, but also can solve the problems of enhancement and poor reproducibility of SERS detection signals. The phenol recognition SERS probe disclosed by the invention hasremarkable universality, can be widely used for immunoassay using the ALP as an enzyme label to measure a variety of biomolecules, lays a solid foundation for the development of immune technology based on SERS detection, and has a very large development space and a broad application prospect in the fields of biological and chemical detection, medical diagnosis, and the like.

The invention provides a preparation method of an Ag-SiO2-Ag nanosphere array. The method comprises the following steps: forming a layer of Ag thin film on the surface of a monocrystalline silicon sample wafer by virtue of thermal vacuum evaporation; putting the monocrystalline silicon sample into a chemical vapor deposition reaction chamber for heating to a preset temperature, so that the Ag thin film is dehumidified in a solid state and formed into Ag nanoparticles; introducing a reactant gas silane at the preset temperature so that a layer of extremely thin silicon nano-film can be evenly deposited on the surface of the Ag nanoparticles, thereby obtaining an Ag-Si core-shell nanosphere array structure; next, taking out the monocrystalline silicon sample and putting into an oxygen atmosphere for heating so that the Si nano-shell can be oxidized into SiO2; further performing thermal vacuum evaporation to form an Ag thin film with a preset thickness on the surface of the sample, thereby forming the Ag-SiO2-Ag core-shell nanosphere array structure which can be taken as a surface-enhanced Raman scattering (SERS) substrate. The invention aims at providing a technical scheme of the preparation method of the Ag-SiO2-Ag nanosphere array having the SERS effect.

The present disclosure provides a bimetallic nanostructure with stimuli-responsiveness, including: a metal seed; a nanogap including a dopamine-modified stimuli-responsive copolymer attached to only a portion of the metal seed; and a metal shell surrounding the nanogap. The bimetallic nanostructure has a controllable interior nanogap, and may be used as a surface-enhanced Raman scattering (SERS) nanoprobe with improved SERS signals by virtue of the presence of the interior nanogap.

The invention discloses a lateral flow immune test strip based on an ordered micro-nano structure. The lateral flow immune test strip is used for detecting a target in an analyte. According to the test strip, a base is used as a substrate, a sample pad, a conjugate pad, a chromatography pad, an ordered micro-nano structure detection pad and an absorption pad are sequentially distributed on the substrate from left to right, the sample pad is a target loading area, nanoparticles capable of being coupled with a target are combined on the conjugate pad, the ordered micro-nano structure detection pad is arranged on the chromatography pad, and a detection area and a quality control area are distributed on the ordered micro-nano structure detection pad; the sample pad and the conjugate pad are overlapped together, the conjugate pad and the chromatography pad are overlapped together, the ordered micro-nano structure detection pad is fixed on the chromatography pad, and the chromatography pad and the absorption pad are overlapped together; in practical application, when a sample reaches a detection area, multi-target detection can be realized by collecting signals; the test strip has the advantages of short detection time, simplicity and convenience in operation, low cost, simultaneous detection of multiple targets and the like, and is expected to be widely applied to the field of rapiddetection.

Provided herein are substrates useful for surface-enhanced Raman spectroscopy (SERS), as well as methods of making substrates. The substrates comprise a support element; a nanoparticulate layer; a SERS-active layer in contact with said nanoparticulate layer; and optionally, an immobilizing layer disposed between said nanoparticulate layer and said support element; wherein if the optional immobilizing layer is not present, the nanoparticulate layer is thermally bonded to the support element; and if said optional immobilizing layer is present, said nanoparticulate layer thermally bonded to said immobilizing layer, and optionally, further thermally bonded to said support element. In addition, methods of making the substrates, along with methods of detecting and increasing a Raman signal using the substrates, are described herein.

The invention discloses a method for synthesizing a silver substrate and application of the method, and relates to the technical field of research of surface phenomena related to adsorption molecules, particularly a synthesizing technology for a metallic nano material substrate used as a probe molecule in SERS detection. The method comprises the following steps: adopting a hydro-thermal synthesis method, using silver nitrate as a silver source, using urea as an ammonia source, using formaldehyde as a reducer, changing the pH value of a solution through the urea, under the hydro-thermal condition, gradually reducing silver, and then preparing the silver substrate, wherein the silver substrate can be used as the substrate for researching surface enhanced raman scattering (SERS). The method is simple, convenient and fast, the used raw materials are relatively cheap, the synthesized product is stable in surface and convenient to store, and the method can be directly used for product representation and SERS detection.

The invention relates to a method for detecting the content of dioxane in children cosmetics. The method comprises the following steps: (1) pretreating a sample to be detected so as to form a sample solution; (2) uniformly mixing the sample solution with prepared nanometer silver colloid so as to form a sample mixed solution; (3) dropping the sample mixed solution on a substrate, and naturally airing, thus obtaining a detection sample; (4) detecting the detection sample by adopting surface-enhanced Raman scattering, thus obtaining an SERS (surface enhanced Raman spectrum) spectrogram of the detection sample; and (5) comparing the obtained SERS spectrogram of the detection sample with an SERS spectrogram of a dioxane standard solution, and calculating so as to obtain the content of the dioxane in the detection sample. The method is simple, convenient and fast to operate and can be used for rapidly carrying out qualitative and quantitative analysis on the content of the dioxane in children cosmetics.

The invention discloses gold nanoparticles as well as a preparation method and application thereof. The gold nanoparticles are used for enhancing the SERS effect and are spinous gold nanoparticles or triangular gold nanoparticles, spinous structures are arranged on the surfaces of the spinous gold nanoparticles, and the particle size of the particles ranges from 60 nm to 165 nm; the triangular gold nanoparticles are in the shape of a regular triangle, and the side length of the triangular gold nanoparticles ranges from 60 nm to 70 nm. The invention also provides a preparation method and application of the particle, AuNPs with special morphology is used as an SERS substrate, based on the special size morphology and surface structure of the AuNPs, the SERS signal of a detection sample can be significantly enhanced, and the particle has excellent sensitivity, detection limit and repeatability stability for detection of parathion-methyl.

The invention discloses preparation and application of a Fe3O4@GO@Ag and gold nanostar SERS substrate. The preparation comprises the steps of synthesizing magnetic ferroferric oxide nanoparticles by an improved solvothermal method, carrying out amination modification on the magnetic ferroferric oxide nanoparticles, and coating a graphene oxide shell on the outer layer by electrostatic adsorption,wherein silver nanoparticles can be nucleated and grown in situ by a large specific surface area and a large number of oxygen-containing functional groups on the surface, so that a core-shell satellite structure is realized; the graphene oxide has obvious Raman peaks (G peak, D peak and 2D peak) and can be used as a stable internal standard to reduce experimental errors; the gold nanostars are synthesized through simple chemical reduction and are connected to Raman beacon molecules with Raman signals in a biological silence area through gold-sulfur bonds; and after the two substrates are modified with a primary antibody and a secondary antibody respectively, rapid and sensitive detection of the antigen can be realized. The method is simple in synthesis, easy to separate and high in sensitivity.

The invention discloses a design method of an SERS substrate based on a surface plasmon polariton effect, which comprises the following steps of: setting a structure of an SERS substrate, including aSiO2 substrate layer, an Au metal film layer and a SiO2 dielectric layer, by adopting a time domain finite difference algorithm; determining initial conditions of simulation; sequentially changing thethickness of the Au metal film layer, the thickness of the SiO2 dielectric layer, the thickness of the Au top metal layer and the gap size of the double-circular-hole structure, calculating the electric field intensity distribution of the SERS substrate by utilizing FDTD solution software, calculating an enhancement factor of the SERS substrate according to the electric field intensity distribution, and screening out a structure with a relatively large enhancement factor as the optimized SERS substrate. According to the structure designed by the invention, incident light energy can be effectively converted into surface plasma wave energy, and effective coupling of LSPR and PSPR is generated by etching the composite film SERS substrate of the nano double-hole ordered array, so that an SERSsignal is enhanced to the maximum extent.

The invention relates to a preparation method for a nano gold-silver composite material substrate of a core-shell structure, and belongs to the technical field of surface-enhanced Raman scattering (SERS). The preparation method comprises the following steps that HAuCl4 is reduced into elemental gold by using Na3C6H5O72H2O by means of a hydrothermal reduction method, and cleaning and dispersing are conducted to obtain Au seed solutions; the Au seed solutions, Na3C6H5O72H2O solutions and ascorbic acid solutions are added into deionized water, uniformly stirred, and subjected to a water bath at 40 DEG C for 15 minutes; silver nitrate solutions are added dropwise at a constant speed, continuously stirred, and subjected to a water bath at 40 DEG C for 30-40 minutes; nano gold-silver composite material sol of a core-shell structure is obtained after cleaning; and the sol is dripped on a clean silicon wafer and covers the surface of the silicon wafer, vacuum drying is performed, and the substrate is prepared. According to the preparation method, the problem of remarkable anisotropism of single noble metal nanoparticles is greatly solved; and the SERS signal on the substrate is greatly enhanced, and the lowest detection limit of the substrate is 109M.

The invention relates to a nucleic acid structure detection method based on surface enhanced Raman spectroscopy. The nucleic acid structure detection method comprises: (1) preparing a silver nanoparticle sol modified and cleaned with iodine ions; and (2) adding a to-be-detected DNA sample to a centrifuge tube filled with the iodine ion modified silver nanoparticle, adding a buffer solution with the PH value of 3.0-5.0, adding an aluminum ion or titanium ion aggregating agent, and carrying out surface enhanced Raman spectroscopy detection. According to the present invention, the method effectively detect the secondary structure of nucleic acid, has the advantages of simpleness, rapidness and the like of SERS, and further has extremely high reproducibility and extremely high reliability; themethod overcomes the difficulty in the detection of the secondary structure of nucleic acid in the traditional SERS detection, has advantages of simple operation steps, rapidness, high sensitivity and good reproducibility, can obtain the signal with the extremely high signal-to-noise ratio, and achieves the high sensitivity detection on various nucleic acid secondary structures.

The invention discloses a cancer diagnosis and treatment integrated nano reagent which comprises a miRNA recognition probe prepared by modifying the surface of AuNP with a Y-type DNA structure and an SERS probe prepared by modifying AuNP with a double-stranded DNA connector and Raman molecules, and the invention further discloses a preparation method and application of the cancer diagnosis and treatment integrated reagent. According to the cancer diagnosis and treatment integrated nano reagent disclosed by the invention, under the driving of ATP (Adenosine Triphosphate) in cancer cells, a Y-type DNA structure specially designed on AuNP and a double-stranded DNA connector are subjected to conformational transformation triggered by miRNA-106a, miRNA-106a is released and circularly amplified, and SERS (Surface Enhanced Raman Scattering) signals are initiated to remarkably enhance the recognition of the cancer cells; meanwhile, DNAzyme generated and amplified through conformation conversion can catalytically crack Survivin mRNA and c-Jun mRNA, and effective double gene silencing treatment is achieved.