69results about How to "Good Raman enhancement effect" patented technology

The invention belongs to the technical field of inorganic functional materials, in particular to a method for preparing a large-size, flexible and unsupported nano-silver-graphene composite film having the Raman enhancement effect, which comprises the following steps of: obtaining silver ion-graphene oxide colloid solution by adsorbing silver ions through self-assembly by utilizing strong adsorption function of graphene oxide and the functions of a thin plate, obtaining a silver ion-graphene oxide film through a vacuum suction filtration process, processing the obtained film through a high-temperature heat treatment reduction process, and finally, obtaining the nano-silver-graphene composite film. The nano-silver-graphene composite film prepared by the invention has excellent Raman enhancement effect.

The invention discloses a super-hydrophobic nano-silver raman-enhanced substrate material and a preparation method thereof. The preparation method comprises the following steps: performing surface de-oiling and acid washing on a base material in sequence; performing chemical deposition in chemical silver-plating deposition liquid at 20-80 DEG C for 2-30 minutes; and storing a nano-silver substrate obtained by the deposition for 1-2 months to obtain the super-hydrophobic nano-silver raman-enhanced substrate material. The method is a one-step chemical deposition process and is simple and feasible, and the super-hydrophobic surface with high contact angle hysteresis can be obtained without any surface modification; the prepared substrate has an ultrasensitive raman-enhanced effect, rhodamine 6G is taken as a probe molecule, and the detection limit is reduced to 10-12mol/L; meanwhile, the substrate is very good in surface structure stability and excellent in performances of acid resistance, alkaline resistance, organic solvent resistance, low temperature resistance, high temperature resistance and the like, and can meet the actual application needs.

The invention discloses a Raman probe. The Raman probe comprises a nanometer core, a first Raman signal layer and a shell layer. The nanometer core is coated with a first Raman signal layer; Raman signal molecules are distributed in the first Raman signal layer; the shell layer has a first layer and a second layer; the first Raman signal layer is coated with the first layer; and the second layer coats the first layer and is provided with a gap. The Raman probe has the advantages of the high Raman signal and the good signal repeatability. The invention also relates to a preparation method and application of the Raman probe. The preparation method is simple, and the Raman probe can be used for the ultra-sensitive and ultra-fast Raman detection and imaging technologies.

The invention relates to a silver nanocrystalline chemical preparation method with a surface raman enhancing effect. The method includes the steps of dissolving polyvinylpyrrolidone in deionized water to prepare a water solution, adding strong alkali and a glucose solution to the water solution, fully stirring the mixture so as to evenly disperse the strong alkali and the glucose solution, dropwise adding a silver nitrate water solution to the mixture, moving reaction liquid into a reaction kettle to react, and washing and drying the reaction product so as to obtain solver nanometer sol. According to the method, raw materials are cheap; the method is environmentally friendly; silver nanocrystalline particles in the uniform size can be obtained, and the nanometer particles have the remarkable raman enhancing effect on PVP and pyridine.

The invention discloses a raman multiple detection method based on a silver nanoparticles tetrahedron, belonging to the technical field of analytical chemistry. The silver nanoparticles tetrahedron is successfully assembled by a DNA-mediated nanoparticles self-assembly technology; three segments of NDAs containing to-be-detected articles SDM, AFMI and OTA nucleic acid adapter segments and three beacon molecules are introduced into the silver nanoparticles tetrahedron by utilizing the special steric configuration of tetrahedron; a raman multiple-detection system based on the silver nanoparticles tetrahedron is successfully built; when the to-be-detected articles exist, the steric configuration of the tetrahedron changes to cause change of raman signals so as to detect; the change of raman signals of the three beacon molecules corresponds to the concentration of three targets, so that simultaneous detection of the three targets SDM, AFM1 and OTA is achieved; the method has extremely high sensitivity and good specificity; the effects on the detection result caused by random aggregation of the nanoparticles are avoided; and application of a raman sensing technology in practice is facilitated.

The invention provides a preparation method of a thin film with a Raman enhancing performance. A silver and silicon dioxide nano composite thin film with the size of 100nm-150nm is prepared on a smooth quartz or mono-crystalline silicon substrate by using magnetron sputtering co-sputtering; one layer of nano silver thin film with the size of 30nm-50nm is continually sputtered on the surface of the composite thin film; the thin film is put into an annealing furnace and is heated to 900-940 DEG C under a protective atmosphere to be annealed for 1-3 hours; and then the thin film is cooled to a room temperature to obtain the thin film with the Raman enhancing performance. The preparation method has a simple preparation process, good repeatability and good stability.

The invention discloses a preparation method of a surface enhanced Raman scattering substrate based on a spirogram ordered porous membrane. The method includes the steps of: (1) preparing the spirogram ordered porous membrane; (2) performing spin coating of dimethylaminoethyl methacrylate on the surface of the spirogram ordered porous membrane; (3) placing the spirogram ordered porous membrane in a silver nitrate water solution and a sodium borohydride water solution successively to conduct fixation for certain time; and (4) cleaning the spirogram ordered porous membrane, thus obtaining the surface enhanced Raman scattering substrate based on a spirogram ordered porous membrane and used for detection of probe molecules. The method has the advantages of no need of complex equipment, low cost, simplicity and conveniency, and is applicable to a variety of base materials.

The invention discloses a high-sensitivity food colorant detection method, which comprises the steps of dropping 10<-8>mol/L to 10<-3>mol/L of food colorant standard liquid on a flower-shaped nano silver particle SERS (Surface Enhanced Raman Scattering) substrate, and collecting a raman spectrogram and data of the food colorant standard liquid through a raman spectrometer; further adopting a principal component analysis method for processing the raman spectrum data of the food colorant standard liquid so as to obtain a raman spectrum intensity-food colorant concentration relational expression of the food colorant standard liquid; processing food to be detected into a solution, dropping the solution on the flower-shaped nano silver particle SERS substrate, collecting an SERS spectrogram and data of the food solution to be detected through the raman spectrometer, comparing with the SERS spectrogram of the food colorant standard liquid to obtain the attribute of a colorant in food to be detected, and obtaining the content of the colorant in the food to be detected through the SERS spectrum intensity-food colorant concentration relational expression of the food colorant standard liquid. The method can be used for detecting a trace colorant in the food, and is simple to operate.

The invention discloses a method for preparing silicon core and golden shell nanoparticles by an ultrasonic-assisted hydroxylamine hydrochloride seed-growth method. According to the method, the hydroxylamine hydrochloride seed-growth method and an ultrasonic chemistry method are combined; a silicon dioxide nanoparticle is taken as the core by each prepared silicon core and golden shell composite nanoparticle; the surface of each silicon dioxide nanoparticle is modified with polyethyleneimine (PEI) under the ultrasonic condition, and self-assembly is performed by PEI on the surface of the corresponding silicon dioxide nanoparticle to form a cationic polymer; electronegative small-particle size metal nanoparticles are adsorbed to serve as a seed structure by utilizing powerful electropositivity of a PEI layer through an electrostatic method; and finally, a layer of continuous and full golden shell is formed on the surface of each silicon dioxide nanoparticle by employing the ultrasonic-assisted seed-growth method.

The invention discloses a preparation method of a SiO2@Ag@ZrO2 nano material with a multilayer core-shell structure for SERS detection, and method has simple steps and convenient operation. In the prepared SiO2@Ag@ZrO2 nano material with a multilayer core-shell structure, Ag nano particles are uniformly adsorbed on the surface of a SiO2 microsphere, and SERS signals with high repeatability and strong stability can be generated, thereby having excellent Raman enhancement effect; and ZrO2 is wrapped outside, so that the stability is high, the environmental adaptability can be improved, and the Ag nano particles are protected from being damaged.

The invention discloses a composite gold nano material for pesticide residue detection and a preparation method thereof, and belongs to the technical field of nano materials. The composite gold nano material for pesticide residue detection is prepared by using discarded egg membranes as a template, and then reducing the chloroauric acid to gold nano particles by using a hydrazine hydrate solutionas a reducing agent. The preparation method of the composite gold nano material for pesticide residue detection comprises the following steps of: eggshell membrane pretreatment; preparation of an eggshell membrane carrier; gold ion adsorption; in situ reduction of gold nano particles; and preparation of the composite gold nano material carried by the eggshell membrane. The composite gold nano material has high sensitivity to pesticides and can be used for rapid detection of pesticide residue, and has broad application prospects. The preparation method is simple, the source of raw materials isrich, the cost is low and the price is low.

The invention relates to a preparation method of a nanoparticle film, in particular to a method for assembling a silver nanoparticle film by using a gas-liquid interface. The method comprises the following steps of: directly reducing a silver nitrate solution with sodium borohydride in an ethanol-water mixed system to prepare cinnamic acid-coated silver nanoparticles; and capturing the silver nanoparticles in the solution on the gas-liquid interface to form a two-dimensional silver nanoparticle film. The shape of the silver nanoparticle film is controlled by adjusting the molar ratio of cinnamic acid to silver nitrate, so that surface-enhanced Raman scattering active substrates with different enhancing capabilities are obtained. The silver nanoparticle film has a very good Raman enhancingeffect. Compared with the prior art, the method has the advantages of low cost, environmentally-friendly synthesis, high stability and simple process steps.

The invention discloses a preparation method and application of an SERS film substrate based on MXene, and relates to the technical field of SERS spectrums. The method comprises the steps of selectively etching away an Al atomic layer in a precursor MAX material by using lithium fluoride-hydrochloric acid as an etching layering agent; repeatedly cleaning the obtained double-transition metal carbide two-dimensional layered material with deionized water, and centrifuging; dispersing in deionized water, shaking, and carrying out centrifugal suction filtration; and obtaining the novel self-supporting SERS film substrate. The preparation method disclosed by the invention is simple to operate and low in cost, has the advantages of high sensitivity, good Raman enhancement effect, high reproducibility and the like, can be applied to trace detection in the fields of environment, food safety, biomarkers and the like, and has a wide application prospect.

The invention discloses a surface enhanced Raman scattering (SERS) substrate and a preparation method thereof. The SERS substrate is composed of a first SiO2 layer, an Ag layer with a gap circular ring, a second SiO2 layer and two equilateral-triangle-shaped silver sheets from bottom to top, wherein the second SiO2 layer is composed of two parts: one part is located on the surface of the Ag layer with the gap circular ring and the other part is located on a connecting surface of the gap circular ring and the first SiO2 layer; the two equilateral-triangle-shaped silver sheets are located on the second SiO2 layer located in an inner diameter region of the gap circular ring; the minimum distance between the apex of one equilateral-triangle-shaped silver sheet and the apex of the other equilateral-triangle-shaped silver sheet is 1nm to 15nm. According to the SERS substrate provided by the invention, the maximum Raman signal enhancement time can reach 10<13> and the average Raman signal enhancement time can reach 10<6>; the SERS substrate has a relatively good Raman enhancing effect.

The invention discloses a preparation method of a silver nanowire with a surface Raman enhancement effect. The preparation method comprises the following steps: (1) preparing 10 mL of Na2S ethylene glycol solution with the concentration being 0.2 mmol/L; (2) weighing 0.174 g of PVP and dissolving PVP in the Na2S ethylene glycol solution in step (1) to obtain a solution A; (3) weighing 0.017 g of AgNO3 and dissolving AgNO3 in 10 mL of an ethylene glycol solution to obtain a solution B, and transferring the solution B into a constant-pressure dropping funnel; (4) dropwise adding the solution B in the solution A to obtain a solution C; (5) transferring the solution C into a hydrothermal reactor, and reacting the solution C for 2.5 hours in a drying box; (6) taking out the reactor, standing and naturally cooling to the room temperature to obtain a solution D; (7) adding the solution D in acetone, and carrying out centrifugal separation on the solution for 10 minutes at the speed of 10,000r/min; and washing precipitates with deionized water, centrifuging under the same conditions, repeating for 5 times, and finally dispersing the precipitates in deionized water to obtain a silver nanowire solution; and (8) dropwise adding 3 mL of the silver nanowire solution on a silicon wafer, and drying for measurement. The preparation method of the silver nanowire with the surface Raman enhancement effect has the advantages that a detection result is accurate, a preparation method is simple, and a Raman enhancement effect is achieved.

The invention discloses a polymer-based multi-element surface-enhanced Raman detection substrate and a preparation method and cancer diagnosis application thereof. The polymer-based multi-element surface-enhanced Raman detection substrate sequentially comprises a polymer base material, a resin layer, a noble metal film layer, a metal oxide film layer and a three-dimensional island-shaped ultrathin silver film which are arranged in a mutual overlapping manner; the island-shaped structure in the three-dimensional island-shaped ultrathin silver film is a uniformly distributed nano structure, and the thickness of the silver film is 1.5 to 20 nm. The flexible surface-enhanced Raman scattering substrate has the advantages of simplicity, convenience, high sensitivity, good consistency and high throughput, and can be used for realizing early diagnosis of cancers.

The invention relates to the technical field of hepatitis C virus diagnosis, and discloses a saliva diagnostic sensor as well as a preparation method thereof and application thereof in detection of hepatitis C. The sensor comprises a substrate, a metal film and composite nano rolls, wherein the metal film covers the substrate; the composite nano rolls are dispersed on the metal film; the compositenano rolls respectively have a nano roll structure which is formed by enabling metal nanoparticles to grow on the surface of a graphene material in situ, then rolling up the graphene material and enabling the metal nanoparticles to be wrapped in the graphene material. The preparation method of the sensor comprises the steps of enabling a liquid phase reaction system containing the graphene material, metal ions and an ethanol solution to be subjected to an ultrasonic reaction to prepare the composite nano rolls; coating the substrate, with the sputtered metal film, with dispersion liquid of the composite nano rolls, and drying to obtain the saliva diagnostic sensor. Compared with the prior art, the saliva diagnostic sensor has the advantages of simple operation, rapid detection speed and high accuracy.

The invention is applicable to the technical field of Raman spectrum detection, and provides a surface enhanced Raman spectrum detection method based on an aggregation restabilization strategy, which comprises the following steps: S1, uniformly mixing colloidal gold with a to-be-detected object; s2, adding an aggregating agent into a system in the S1, and quickly and uniformly mixing, so that the colloidal gold is aggregated to generate a colloidal gold aggregate; s3, adding an acrylamide-methylene bisacrylamide solution into a system in S2, then adding a tetramethylethylenediamine solution and an ammonium persulfate solution, and uniformly mixing; s4, pouring the mixture obtained in S3 into a beaker, and placing the beaker in an incubator until the colloidal gold aggregate SERS detection substrate with stable polyacrylamide hydrogel is formed; and S5, taking out the SERS detection substrate formed in S4, and placing the SERS detection substrate on the surface of the tin foil paper.According to the detection method, the sensitivity of SERS detection is improved, and the stability and uniformity of SERS detection of the gold nanoparticle aggregate are greatly improved.

The invention provides a preparation method for a Raman enhancement substrate. By the utilization of magnetron sputtering, a zinc nanometer film of a certain thickness is prepared; a silver nitrate-cetyl trimethyl ammonium bromide (CTAB) mixed solution of a certain concentration is prepared; a prepared zinc nanometer film glass sheet is placed into the mixed solution for certain time and then taken out; the substrate which is taken out is washed several times with alcohol and deionized water until CTAB is completely washed away. The preparation method is simple in technology, easy to control and good in repeatability and has commercial value.