44results about How to "Strong Raman signal" patented technology

The present invention relates to a microfluidic chip, in particular, it relates to a microfluidic chip with surface enhanced Raman spectrum (SERS) active substrate and its preparation method. On the microfluidic chip, at least a microchannel is set, on the total or partial inner wall surface of said microchannel is set a layer of rough metal film with SERS activity. Besides, said invention also provides the concrete steps for preparing said microfluidic chip.

The invention discloses a three-dimensional metal-graphene composite substrate and a preparation method thereof. The composite substrate disclosed by the invention is composed of a first nano layer, a graphene layer and a second nano layer, wherein the first nano layer is deposited on the surface of an amorphous carbon underlayer, the graphene layer is arranged on the surface of the first nano layer through spin coating, the second nano layer is deposited on the surface of the graphene layer, and the first nano layer and the second nano layer are gold or silver nano layers. According to the method, an active substrate with a good surface enhanced Raman effect is constructed; and the three-dimensional metal-graphene composite substrate is simple in preparation method, high in efficiency, and low in preparation cost.

The invention relates to a metal surface enhanced Raman scattering substrate with a three-dimensional period structure and a preparation method thereof and belongs to a chemical detection technology. The preparation method comprises the following steps of: soaking an amine-modified bio-template into a chloroauric acid solution so that catalyzed metal ions are introduced; then carrying out chemical plating treatment on activated sodium borohydride to obtain a metalized bio-template; and finally, carrying the metal ions on the metalized bio-template so as to obtain the metal surface enhanced Raman scattering substrate. The metal surface enhanced Raman scattering substrate prepared by the preparation method, provided by the invention, carries on and copies the three-dimensional period structure of a natural organism. The technology is simple and flexible and the cost is low. The obtained three-dimensional period metal substrate has higher surface enhanced Raman effects, can be used for effectively enhancing Raman signals, and has the advantages of uniform signal response and good repeatability.

The invention discloses a preparation method of a carbon-based quantum dot/nano-silver surface enhanced raman base. The preparation method comprises the following steps: dissolving carbon-based quantum dots and silver ions in a water solution; adding sodium boro-hydride serving as a reducing agent under a stirring state, so as to prepare a carbon-based quantum dot/nano-silver composite material. The preparation method is simple, convenient, easy, free of pollution, fast in reaction, and high in operability. As the carbon-based quantum dots on the surface of the carbon-based quantum dot/nano-silver composite material comprise a large quantity of oxygen-containing functional groups, the carbon-based quantum dot/nano-silver composite material is favorable in dispersity and long-lasting in stability in water. More importantly, as the carbon-based quantum dot/nano-silver composite material comprises a large quantity of 'notches', the surface enhanced raman activity is excellent; as the carbon material on the surface of the carbon-based quantum dot/nano-silver composite material can adsorb benzene series via electrostatic adsorption and Pi-Pi function, the carbon-based quantum dot/nano-silver surface enhanced raman base can be applied to surface enhanced raman detection of the benzene series.

The invention belongs to the technical field of digital microfluidics, and particularly relates to a target detecting method based on a digital microfluidic technology and a surface-enhancement Ramanscattering technology. The system mainly comprises a digital microfluidic chip and a surface-enhancement Raman probe. The digital microfluidic chip consists of an upper polar plate and a lower polar plate. The surface-enhancement Raman probe comprises a metal core, a Raman report molecule and a shell layer, and the Raman report molecule is embedded between core-shell structures. By the method automated control on discrete droplets on an electrode array is implemented based on a dielectric wetting principle, a reaction system on a chip is constructed, and Raman signals are output rapidly in real time. The target detecting method has the advantages of full automatic processing, simplicity and rapidness, high sensitivity, suitability to a complicated biosystems and the like. A plurality of samples are simultaneously detected in parallel by program control; and the target detecting method can be widely applied to detection of various types of targets, and particularly can be used for detecting rare samples and infectious samples.

A method for preparing a transparent Raman effect film relates to preparation of optical fiber films and aims to solve the problems of complicated equipment and difficulty in controlling a production process of an existing method for preparing SERS (surface enhanced Raman scattering) base materials. The method includes the steps: firstly, preparing cellulose acetate solution with acetone, acetic acid and cellulose acetate; secondly, uniformly mixing Ag NPs suspending liquid and the cellulose acetate solution to obtain spinning liquid; thirdly, spinning the spinning liquid into a nano-fiber nonwoven felt by means of electrostatic spinning process; and fourthly, tiling the cut nano-fiber nonwoven felt in a slot of a composite film forming tool, pouring polyvinyl alcohol water solution into the slot, leading the polyvinyl alcohol water solution to be lower than the upper edge of the slot of the composite film forming tool, and maintaining pressure and drying to obtain the transparent Raman effect film. The method is mainly used for preparing the transparent Raman effect film.

The invention discloses a method for preparing a surface-enhanced Raman spectroscopy substrate of a silver self-assembly under the assistance of amino acids, relating to the preparation method of the surface-enhanced Raman spectroscopy substrate and aiming at solving the problems of poor uniformity of signals, low sensitivity, complex preparation process and high cost of a nano-silver surface-enhanced Raman spectroscopy substrate which is prepared by using the prior art. The method for preparing the surface-enhanced Raman substrate comprises the following steps of: injecting little amount of amino acids into a silver nitrate solution under an ice-water bath condition, cooling for a period of time, and then adding ascorbic acid with a certain concentration and reacting to obtain the surface-enhanced Raman spectroscopy substrate of the silver self-assembly with a certain three-dimensional structure. The surface-enhanced Raman spectroscopy substrate can be used for detecting organic molecules and biological molecules of ppm-grade concentration and has the advantages of uniform signal response, high sensitivity, simple and rapid method and low cost. The method disclosed by the invention is applied to the detection field of organic molecules and biological molecules.

The invention discloses application of polymer microspheres to Raman detection. Methacrylate/amide polymer monomers or styrene polymer monomers containing alkynyl, cyano, azido or a carbon-deuterium bond group are prepared into the polymer microspheres with the particle diameter from a nanometer grade to a micron grade through an emulsion polymerization or dispersion polymerization method; the polymer microspheres have a remarkable Raman signal under the condition of no metal sensitization structure; and a Raman characteristic peak signal is located in a Raman quiet zone (1800cm<-1> to 2800cm<-1>) in a living organism and can be used as a marker for biological imaging.

The invention relates to a temperature-sensitive intelligent response SERS substrate and a preparation method and application thereof. The preparation method comprises the following steps of taking azodiisobutyronitrile as an initiator, methanol as a solvent and 1-vinyl-3-ethylimidazolium bromide and N-isopropylacrylamide as monomers to carry out copolymerization reaction;re-dispersing the copolymer into the deionized water after precipitation, filtering and drying; adding an excessive amount of a tetrachloroauric acid solution, carrying out an ion exchange reaction, removing the unreacted tetrachloroauric acid, carrying out in-situ reduction by using sodium borohydride to generate poly (NIPAm-co-ViEtImBr)-AuNPs, continuously immobilizing probe molecules by using an ion exchange effect, and carrying out a Raman signal test. According to the invention, the intelligent polymer PNIPAM with temperature-sensitive response, the gold nanoparticles with enhancement effect on Raman signals andthe probe molecules are successfully integrated through a bridging effect of the ionic liquid.

The invention discloses a method of assembling a nano necklace based on DNA nanoribbon templating and gold particles; the method comprises: synthesizing gold nano particles, mixing DNA framework chains having molar concentration of 1-5 Mumol/L and staple single chains having molar concentration of 1-5 Mumol/L according to a size ratio of 1:1 to 1:5, adding gold nano particles, stirring and mixing well, and performing gradient annealing on the solution of step C at 45-25 DEG C to form nano necklace structure. Gold particles 20 nm in size and DNA nanoribbons specifically designed are assembled via one step to form the nano gold chain, nano gold is modified via 4-mba Raman signal molecules, and its Raman signal changes are detected. The method has the advantages of good DNA nanoribbon structure, high forming yield, low external environment requirements and the like; 4-mba signal molecules have great Raman signals, modifying the nano necklace so that the necklace has better advantages in Raman detection; the nano necklace is characterized by the aid of an atomic force microscope and a transmission electron microscope, and the necklace also has the advantages of good simplicity, good reliability, low cost and the like.

The invention discloses an antibiotic Raman spectrum detection method based on a surface-modified magnetic nano-silver flower substrate. The detection method comprises the following steps: coating Fe3O4 nanoparticles of 200nm with a SiO2 layer, generating a large amount of silver seeds on the surface of the SiO2 shell, and breeding a flower-shaped structure by taking seeds as a core; connecting 1-hexanethiol with Ag shell through a sulfhydryl group, and enriching antibiotics by using a surface self-organization hydrophobic layer; diluting the two kinds of antibiotics respectively with methanol water and milk to different concentrations, and purifying and enriching with a SPE (Solid-Phase Extraction) column; acquiring lowest detection limits of the antibiotics in different substances through the Raman spectrum detection, wherein a standard recovery rate is between 78.50 and 113.59 percent. The method is high in recovery rate, and can satisfy the requirement on antibiotics residue analysis. The 1-hexanethiol-modified magnetic nano-silver flower particles prepared by the invention are taken as a high-performance the SERS (Surface Enhanced Raman Scattering) substrate, are provided with a large quantity of hot spots, and can be taken as simple, rapid, high-sensitivity antibiotics residue analysis method.

The SERS virus detection chip for detecting the novel coronavirus comprises an SERS substrate, graphene arranged on the SERS substrate and an ACE2 biological probe arranged on the graphene, and the SERS substrate comprises a Si/SiO2 wafer serving as a base and a metal nanostructure above the Si/SiO2 wafer; the preparation method comprises the following specific steps: (1) preparing a metal nanostructure on a Si/SiO2 wafer to form an SERS substrate; (2) transferring the single-layer CVD graphene to an SERS (Surface Enhanced Raman Scattering) substrate; and (3) modifying ACE2 on graphene to form a new crown detection probe, thereby completing the preparation of the SERS virus detection chip. The ACE2 biological probe molecules and the graphene/periodic nano-metal structure SERS detection substrate are combined to form the new coronavirus biological detection chip, the detection chip is utilized to achieve high-sensitivity detection of the new coronavirus, the detection is rapid and efficient, and the capturing efficiency is higher.

The invention relates to a preparation method and an application of a raman enhancement substrate based on a combination of a club-shaped upconversion material (UC) and an Au@Ag nanomaterial. A principle of the substrate is to use a characteristic that upconversion can absorb visible light emitted by near infrared light, so as to convert the near infrared light to visible light at a local plasma resonance frequency part of an Au@Ag nanoparticle; the local plasma resonance frequency of the Au@Ag nanoparticle is improved; and further, raman signal intensity is improved. The preparation method of the enhancement substrate particularly comprises the steps of preparation of the club-shaped upconversion material (UC), preparation of upconversion material surface modified silicon dioxide (UC@SiO2), preparation of the Au@Ag nanoparticle and assembly (UC@SiO2@Au@Ag) of UC@SiO2 and Au@Ag nanoparticle. The substrate has the maximum advantage that the substrate has a better enhancement effect that a substrate without the upconversion under the same condition, and the signal intensity is improved approximately by 11 times. The invention provides a raman spectrum detection method by taking UC@SiO2@Au@Ag as the substrate. Compared with the traditional raman substrate, the substrate has the very good enhancement effect and very wide application prospects.

The invention provides a compact 266nm short-wave ultraviolet Raman spectrometer which comprises a light source, an external light path, a dispersion system, a receiving system and a signal acquisition system. The light source is an all-solid-state 266nm short-wave ultraviolet laser; the external light path comprises a collimating lens, a first reflector, a dichroscope, a beam expander, an opticalfilter, a relay lens, a coupling optical fiber and a shaping optical fiber bundle, the dispersion system comprises a slit, a second reflector, an off-axis parabolic reflector and a plane reflection type grating, the receiving system is a back-illuminated CCD linear array detector, and the signal acquisition system is a computer. The optical fiber bundle is composed of a plurality of optical fibers, one end of the optical fiber bundle is arranged to be an optical fiber array, the other end of the optical fiber bundle is arranged to be linear, the point-to-line optical fiber bundle improves theluminous flux entering a dispersion system and increases the signal-to-noise ratio of the system, and in addition, the Raman spectrometer dispersion method based on the Littrow structure can effectively reduce spherical aberration and improve the resolution of the spectrometer.

The invention discloses a method for detecting ciprofloxacin in milk, and the method comprises the following steps: carrying out deproteinization operation on a milk sample to obtain a solution to bedetected; placing the surface enhancing reagent in a container; putting the to-be-detected liquid into a container; putting the flocculating agent into a container; uniformly mixing the solution in the container to obtain a mixed solution; performing Raman spectrum scanning on the mixed solution to obtain a Raman spectrum of the mixed solution, and determining whether ciprofloxacin exists in the milk or not based on the characteristic peak of the obtained Raman spectrum. According to the method, a surface enhancing reagent and a flocculating agent are adopted as SERS enhancing reagents, the SERS effect of ciprofloxacin in milk can be enhanced, stronger ciprofloxacin Raman signals are obtained, the detection sensitivity of ciprofloxacin in milk is greatly improved, and the lower detection limit of ciprofloxacin is low.

The invention discloses a method for detecting benzoic acid in drink. The method comprises the steps of enriching benzoic acid in the drink through a silica gel extraction substrate, and detecting the benzoic acid in combination with surface-enhanced Raman spectroscopy. By combining the characteristics of high extraction efficiency, short extraction time and selective extraction of a target from a complicated substrate of a thin film microextraction technology with the advantages of convenience and quickness in detection and high sensitivity of the surface-enhanced Raman spectroscopy, a measuring method for the benzoic acid in the drink, which is easy to operate, high in sensitivity, low in detection cost, convenient and quick, is provided.

The invention discloses a Keemun black tea producing area identification method based on a Raman spectrum fingerprint technology, and belongs to the technical field of agricultural product and food producing area identification. The method for identifying the producing area of the Keemun black tea comprises the following steps: (1) preparing black tea soup; (2) uniformly mixing the black tea soup and the nano-silver sol, drying, and carrying out Raman detection to obtain original Raman spectrum data of the black tea powder; calculating the relative peak intensity; (3) respectively combining the relative peak intensity with stoichiometric method linear discriminant analysis, a K-nearest neighbor method and a random forest method to construct a discriminant model; (4) collecting Raman spectrum data of a to-be-detected sample according to the steps (1) and (2), and calculating to obtain relative peak intensity; and predicting the category of the sample by using the discrimination model in the step (3), and determining the production place of the to-be-detected sample. The discrimination model constructed by the method is high in overall correct recognition rate, and can effectively recognize and classify the Keemun black tea in small-producing areas and the Keemun black tea in large-producing areas.