71results about How to "Enhanced Raman scattering" patented technology

The invention provides a preparation method of a graphene-silver nano particle composite material. A specific preparation process comprises the following steps of: preparing solution of silver ammonia at certain concentration from the solution of silver nitrate and aqueous solution of dilute ammonia, adding the prepared solution of silver-ammonia into the solution of graphene oxide which is subjected to ultrasonic processing, preheating the solution at a certain temperature for a certain time; adding an appropriate amount of glucose into the mixed solution of graphene oxide and silver ammonia, and reacting the mixed solution at the set temperature for a certain time with stirring; performing suction-filtration on a reaction product by using deionized water for many times, and then drying the product to obtain the graphene-silver nano particle composite material. The method is simple, convenient, easy, environment-friendly and efficient; and silver nano particles in the prepared composite material are distributed narrowly, have a uniform particle size (about 25 nm), can be better inserted into graphene slices and can effectively prevent aggregation of the graphene.

The invention discloses a water phase preparation method of a spherical silver nanoparticle with adjustable size, which comprises the following steps of: 10, preparing a silver seed solution : 101, mixing deionized water with a sodium citrate solution, and obtaining a stabilizer solution after stirring; 102, heating the stabilizer solution to the temperature of water bath, adding an AgNO3 solution, and then adding a NaHB4 solution; and 103, utilizing the deionized water to obtain a constant volume after cooling at room temperature, and obtaining the silver seed solution; 20, preparing the spherical silver nanoparticle: 201, adding deionized water to a flask, then adding sodium citrate solution to obtain a reducer solution, and heating the reducer solution to a boiling state; 202, adding the silver seed solution to the reducer solution, and then adding the AgNO3 solution; and 203, cooling at room temperature to obtain the spherical silver nanoparticle. The preparation method can be used for preparing the spherical silver nanoparticle with favorable monodispersity, and the size of the spherical silver nanoparticle can be adjusted.

The invention discloses a two-dimensional and double-cycle ordered structure array and a preparation method thereof. The array is an ordered porous film consisting of metals in a microparticle hole shape and a nanometer hole shape and arranged on a conductive substrate, the nanometer hole in the film is located in the microparticle hole and is in a stacking shape, or the nanometer hole is a single layer and is located at the bottom surface or the external surface of the microparticle hole or covers the internal surface and the external surface thereof, the diameter of the microparticle hole is 1,800-2,200 nm, and the diameter of the thenanometer hole is 180-220 nm. The method comprises the following steps of: firstly, self-assembling by using a polystyrene colloidal ball of one diameter in combination with a solution impregnating method or an electrodepositing method to obtain the ordered hole array of a bowl-shaped metal attached to the conductive substrate; and then self-assembling thereon by utilizing polystyrene colloidal of another diameter in combination with the electrodepositing method to prepare the two-dimensional and double-cycle ordered structure arrays in four structures. The product thereof has the characteristics of a macro-scale system, the preparation method has universality, and the two-dimensional double-cycle and ordered structure array consisting of other conductive materials can be prepared by the method.

A sensor for performing surface enhanced Raman spectroscopy comprises: a) a sensor body having a throughbore; an optical energy source for generating an optical excitation signal; b) a surface enhanced Raman scattering structure that is mounted to the sensor body through which the optical excitation signal is directed for irradiating an analyte, whereupon the analyte generates primary Raman emissions in response to being irradiated by the optical excitation signal, and wherein the surface enhanced Raman scattering structure generates secondary Raman emissions when irradiated by the optical excitation signal; c) an optical detector for generating an output signal that represents the spectral characteristics of the primary and secondary Raman emissions in response to receiving the primary and second Raman emissions; and d) a processor for substantially filtering the secondary Raman emission from the primary Raman emissions and for generating an output signal representing the analyte.

A detector assembly for detecting the presence of analyte molecules, in particular, proteins, uses both Surface Enhanced Raman Scattering (SERS) and Surface Plasmon Resonance (SPR) in synergy. The excitation laser used for SERS provides scattering from a reporter dye to which an analyte molecule is attached in the vicinity of a conducting surface. Simultaneously, a second laser is provided at the critical angle to the conducting surface. The second laser causes a field to be created in the region of the analyte which enhances the Raman scattering effect.

Implemented is a chip for localized surface plasmon resonance sensor, which is able to provide a localized surface plasmon resonance sensor of higher sensitivity. A structure of the invention is characterized by including a planar section and tubular bodies, wherein the tubular bodies are vertically arranged so that openings thereof open at the planar surface of the planar section, an average inner diameter of the openings of the tubular bodies is within a range of from 5 nm to 2,000 nm, a ratio (A/B) of inner diameter A of the openings of the tubular bodies and inner diameter B at the midpoint of the depth from the openings of the tubular bodies is within a range of from 1.00 to 1.80, and the bottom of the tubular bodies is aspherical.

An assay method and kit for detecting a chemical. The method and kit utilize a metal surface capable of surface enhanced Raman Scattering. The metal surface may be provided in the form of one or more nanoparticles, to increase the surface enhanced Raman Scattering capability of the metal surface. The nanoparticles may be treated with one or more additives to further enhance or maintain the surface enhanced Raman Scattering capability of the nanoparticles.

The invention provides an ultrafast laser pulse method for forming nanopores with the diameters of 2 nanometers. The thickness of a metal film layer where the ultra small nanopores with the diameters of 2 nanometers is formed is about 3nm, the nanopores are discretely formed in the metal film layer, and the diameter of each nanopore is about 2nm. The ultrafast laser pulse method comprises the following steps of: dissolving a sodium citrate crystal and poly-vinyl pyrrolidone (PVP) powder in deionized water to form a chemical coating solution; putting a metal sheet into watch glass, and injecting the chemical coating solution into the upper surface of the metal sheet; putting the watch glass near a focal distance of a condenser in a light path, ablating by using an ultrafast laser pulser to obtain suspension containing metal nano products, dripping the suspension containing the metal nano products to a copper screen covered by a carbon film, and drying to obtain the ultra small nanopore; and a metal film in which the ultra small nanopore are formed is applied to porous metal mask plates during near-field imaging with aperture probes, surface-enhanced Raman scattering, detection of single-pore biomolecules and the like.

The invention provides a gas detection system based on a hollow-core anti-resonance optical fiber. The gas detection system comprises a laser device, a first gas cavity, a hollow-core anti-resonance optical fiber, a second gas cavity, a spectrograph and a data processing device, wherein two ends of the hollow-core anti-resonance optical fiber are respectively communicated with the first gas cavityand the second gas cavity; the first gas cavity and the second gas cavity are used for injecting to-be-detected gas into the hollow-core anti-resonance optical fiber; the laser device is used for inputting detection laser into the hollow-core anti-resonance optical fiber; the spectrograph is used for measuring Raman scattering light generated by to-be-detected gas; and the data processing deviceis used for processing a Raman spectrum and analyzing the contents and concentration of to-be-detected gas. The hollow-core anti-resonance optical fiber has the characteristics that the transmission loss is low, the transmission bandwidth is wide, the bending loss is low, the damage threshold is high, and single mode transmission is maintained; and the Raman scattering threshold is reduced, and the contents and the concentration of trace gas can be detected by virtue of pump light with relatively low power.

The invention relates to a preparation method of a micro/nano dendritic silver super-hydrophilicity film and application of the film in a surface enhanced Raman substrate, belonging to the technical field of hydrophilic films. The preparation method comprises the following steps: parallelly arranging a flat high-purity aluminum sheet of which the thickness is no more than 500 mu m and the purity is more than 99% on a substrate, and immersing into a mixed solution composed of a silver nitrate solution with a mol concentration of 0.1-5 mmol/L and dilute sulfuric acid with a mass concentration of 15-65% while keeping the relative position unchanged, wherein the volume ratio of the silver nitrate solution to the dilute sulfuric acid is (3-7):1, the temperature is room temperature, and shaking should be avoided; and growing a micro/nano dendritic silver film on the substrate from the aluminum sheet taken as the center to the periphery through self assembling and spreading, taking out the substrate deposited with the micro/nano dendritic silver film from the solution through a liquid level uniform decline method, separating the remaining aluminum sheet, rinsing multiple times, and naturally drying. The film can be used for a surface enhanced Raman scattering active substrate for quick on-site real-time detection of a trace amount of substances.

The invention discloses a porous graphite-silver nano-diamond composite as well as a preparation method and an application thereof. The composite comprises porous graphite and a silver nano-diamonds, wherein pores of the porous graphite are intercommunicated micropores, and one side of the silver nano-diamond is in adsorption connection with the pore walls of the porous graphite. According to the preparation method, graphene oxide, sodium bisulfite and deionized water are mixed and subjected to ultrasonic oscillation, an obtained mixed solution is left to stand at 90-100 DEG C and cooled, black graphene gel suspended in water is rinsed with deionized water and subjected to freeze drying, obtained spongy porous graphene is soaked in an ethyl alcohol dispersion solution of the silver nano-diamond and taken out, an intermediate product is obtained, then the dried intermediate product is compressed, and the target product is prepared. The composite is quite suitable for serving as an active substrate for SERS (surface-enhanced Raman scattering), so that a laser Raman spectrometer selectively measures the content of dimethyldithiocarbamate pesticides attached to the composite.

The invention discloses a method for rapidly preparing a three-dimensional porous gold-silver alloy nanometer material, which comprises the following steps: adding silver nitrate and ascorbic acid into a gold nano octahedral colloidal solution and reacting for 30 minutes under the condition of 50-80 DEG C so as to prepare a gold@silver nano cubic colloidal solution; uniformly mixing the gold@silver nano cube cubic colloidal solution with deionized water under the action of stirring and irradiating with a laser with a power of 670-680 volts for 60 -90 seconds so as to prepare a gold-silver alloy nanosphere colloidal solution; adding nitric acid into the gold-silver alloy nanosphere colloidal solution and reacting for 0.5-hours to obtain the three-dimensional porous gold-silver alloy nanometer material. The method not only can rapidly prepare the three-dimensional porous gold-silver alloy nanomaterial at room temperature and greatly shorten the preparation time, but also realizes the complete alloying of gold and silver elements; the three-dimensional porous gold-silver alloy nanomaterial has uniform size, large specific surface area, and good monodispersity; the preparation processis simple and easy to operate.

The invention discloses a method for forming a dimer structure by assembling a DNA origami template and a nanometer gold cube based on a surface enhanced Raman effect. The method specifically comprises the five steps of preparation of triangular DNA origami with specific sites; preparation of a sulfydryl DNA modified nanometer gold cube; preparation of three dimer configurations; and high efficiency precise assembly by using agarose gel electrophoresis and a transmission electron microscope representational structure, and surface enhanced Raman scattering by using a scanning electron microscope and dark-field microscope co-location detection assembly structure. The method solves the problems of low assembly repeatability and poor structural stability, a new idea is also provided for construction of nanometer optical materials due to establishment of the method, and the method is of great significance to research of nanophotonics.

The invention relates to a molecular carrier for molecular detection. The molecular carrier comprises a base, an intermediate layer and a metal layer, wherein the intermediate layer is arranged on thesurface o the base; the metal layer is arranged on the surface, far away from the base, of the intermediate layer; the base is a flexible substrate; the intermediate layer comprises a substrate and aplurality of patterned bumps arranged on the substrate; and the metal layer is arranged on the surfaces of the patterned bumps. The molecular carrier further comprises a carbon nanotube composite material which is arranged between the top surfaces of the patterned bumps and the metal layer.

The invention provides a method for detecting methylamphetamine in blood. The method comprises the steps of putting a to-be-detected blood sample, a blood sample of healthy people and a methylamphetamine sample on an optical functional element, respectively measuring Raman spectra of the to-be-detected blood sample, Raman spectra of the blood sample of the healthy people and Raman spectra of the methylamphetamine sample, and judging whether the to-be-detected blood sample contains methylamphetamine or not according to the Raman spectra of the to-be-detected blood sample, the Raman spectra of the blood sample of the healthy people and the Raman spectra of the methylamphetamine sample. The method has the beneficial effects that as the optical functional element can generate a preferable field enhancement effect, clear Raman scattering can be measured; when an aqueous solution of methylamphetamine is located on the optical functional element, the obvious enhancement effect can be generated to a Raman scattering signal, and the relatively clear Raman scattering can still be measured even the blood contains trace amount of methylamphetamine, so that the detection sensitivity of the Raman scattering is effectively improved, the detection limit is reduced, and the Raman scattering of the sample is enhanced.

The invention discloses a production technique of a silver collosol for measuring the Raman spectrum. The silver collosol produced in the technique maintains for long period, and has a stable quality which considerably enhances the Raman spectrum and effectively eliminates the fluorescence obtaining clear and stable Raman spectrum figure fast. It is effective especially on biological molecular Raman spectrum measure.

The invention relates to the technical field of chemical detection, and provides a method for detecting formaldehyde in food based on surface enhanced Raman spectroscopy of a gold nanorod substrate. The method comprises the steps of reacting formaldehyde with AHMT in the presence of sodium hydroxide to generate purple 4-H-MTT, and carrying out laser Raman testing on the solution obtained by the reaction to obtain 4-H-MTT Raman spectrum. According to the linear relation between the SERS spectrum peak value and the formaldehyde concentration, the content of formaldehyde in food can be rapidly determined. Experimental results show that the formaldehyde detection limit of the method provided by the invention is as low as 1.1 nm and is equivalent to 33ng/L HCHO, and compared with the prior art, the method provided by the invention has the advantages of higher accuracy, lower detection limit and wider linear range. Moreover, in the presence of various interfering substances, the influence on the detection result is relatively small, and the selectivity on formaldehyde detection is relatively good.