227 results about "Chloroauric acid" patented technology

The invention relates to the technical field of precious metal recovery, in particular to a process for separating precious metal from copper-nickel smelting waste, which comprises the following steps: crushing and grading the waste, adding a sulfuric acid solution containing etidronic acid, leaching, and washing, drying and crushing filter residues to obtain a pretreated material; mixing the pretreated material with a sodium peroxide-sodium carbonate composite flux, roasting, leaching with water, and filtering to obtain a filter residue B; adding a leaching agent containing hydrochloric acid, sodium chlorate and 1, 2-cyclohexanediamine tetraacetic acid into the filter residue B according to the ratio of 1: 3-1: 5, and filtering to obtain filtrate C and filter residue C; adjusting the pH value of the filtrate C to 1.5-2.5, adding an ethanol solution of sodium N, N-diethyldithiocarbamate, precipitating, washing and calcining to obtain sponge palladium; adding ammonium chloride into the filtrate D, precipitating and calcining to obtain sponge platinum; and leaching the filter residue C by using a hydrochloric acid-chloroauric acid mixed solution containing diphenylthiourea, and replacing and calcining zinc powder to obtain crude gold. According to the process, the leaching rates of platinum, palladium and gold and the product purity are greatly improved; flux and reagent systems are optimized, consumption and energy consumption are reduced, waste liquid treatment is matched for up-to-standard discharge, and efficient resource recovery and environment-friendly cooperation are achieved.

The invention provides a GelMA microneedle patch loaded with chromogenic gold nano bipyramids and a preparation method thereof.The method comprises the steps that citric acid, chloroauric acid and a CTAC solution are mixed, then sodium borohydride is added, and a seed solution is obtained through stirring and standing; mixing chloroauric acid, silver nitrate, hydrochloric acid and CTAB (cetyltrimethyl ammonium bromide), and sequentially adding ascorbic acid and the seed solution to obtain a growth solution; carrying out centrifugation, morphology regulation and chemical etching purification to obtain a chromogenic gold nano bipyramid solution; the preparation method comprises the following steps: reacting gelatin with methacrylic anhydride in PBS, dialyzing and freeze-drying to obtain GelMA; dissolving GelMA in the gold nanoparticle bipyramid solution, and adding a photoinitiator LAP to obtain a mixed precursor solution; and the GelMA microneedle patch loaded with the gold nano bipyramid is prepared through mold casting, centrifugation, ultraviolet light crosslinking and drying demolding. The microneedle extraction and gold nano bipyramid color development integrated scheme is initiated, blood sampling is not needed, the dermis interstitial fluid is extracted in a minimally invasive mode through the microneedle, detection pain and trauma are reduced, the cross infection risk of blood treatment is avoided, and the microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle

The invention discloses a method for recovering valuable metals from copper anode slime step by step, and belongs to the technical field of metallurgy and chemical industry. According to the method, through control over the oxidation-reduction potential, the oxidation-reduction potential is high in the leaching stage, and it is guaranteed that gold, selenium, tellurium and the like can be oxidized to enter a leaching solution; in the reduction stage, gold, selenium and tellurium products are reduced step by step according to the difference of gold, selenium and tellurium in reduction potentials; in the leaching stage, soluble chlorine salt is added while enough oxidation potential is guaranteed, enough chloride ions are provided for the solution, and therefore gold can enter the solution in the form of AuCl4-(tetrachloroauric acid); meanwhile, in the oxidation leaching stage, a small amount of silver enters the solution in the form of silver sulfate or silver complex, and under the condition that enough chloride ions are provided, silver is precipitated and retained in residues in the form of silver chloride, so that separation of gold and silver is achieved, and meanwhile dispersion of gold and silver in the leaching process is reduced. According to the method, valuable metal is efficiently separated and recycled.

The invention provides a preparation method of a nano-gold star material, which comprises the following steps: stirring and heating a chloroauric acid solution, adding a sodium citrate solution, continuously stirring and heating, when the color of the solution is changed from colorless to dark red, adjusting the rotating speed to 600rpm, turning off a heating device, cooling at room temperature, filtering the reacted solution by using a water-based filter membrane, and drying to obtain the nano-gold star material. Removing impurities to obtain a gold seed solution; characterizing the gold seed solution and the gold seed particles; the preparation method comprises the following steps: adding a 4-hydroxyethyl piperazine ethanesulfonic acid solution, a gold seed solution, a hydroxylamine solution and a magnetic rotor into deionized water, dropwise adding a 22.5 mM chloroauric acid solution, adjusting the rotating speed to 700rpm, and reacting for 15 minutes at room temperature to obtain the nano gold star material. The prepared nano gold star material is uniform, stable, adjustable in particle size and high in dispersity, the material is in a three-dimensional multi-branch shape, and the diameter of the material is adjustable within 50-200 nm.

The invention discloses a nano-enzyme detection method for aflatoxin B1, and relates to the technical field of analysis and detection.The method comprises the following specific steps that nano-enzyme preparation and carrier selection are conducted, specifically, nano-gold is prepared through a sodium citrate reduction method to serve as the nano-enzyme, a chloroauric acid solution is added into a round-bottom flask and heated to be boiled, and a carrier is obtained; according to the method, the PNIPAM serves as an immobilization carrier of the nano-enzyme, reversible immobilization of the nano-enzyme is achieved, cyclic utilization of the nano-enzyme is promoted, the detection cost is reduced, after detection is completed, phase change of the PNIPAM can be achieved by changing environmental conditions, and therefore effective separation of nano-gold and the carrier is achieved; after the recovered nanogold is washed and subjected to re-functionalization treatment, the catalytic activity of the nanogold is maintained, and the nanogold can be used for detecting aflatoxin B1 again, so that the utilization rate of the nano-enzyme is increased, and the waste of resources is reduced.

The application provides a preparation method of a SERS substrate of a zirconium-based MOF-808 / AuNPs. The method comprises three steps: in the first step, an AuNPs solution is prepared by using deionized water, chloroauric acid and sodium citrate to perform an oil bath reaction to obtain the AuNPs solution; in the second step, MOF-808 is prepared by mixing zirconium chlorohydrate, 1,3,5-benzene tricarboxylic acid, N,N-dimethylformamide and formic acid, and then performing a hydrothermal reaction on the mixed solution, centrifuging and vacuum drying to obtain activated MOF-808-Zr powder; in the third step, the activated MOF-808-Zr powder is dissolved in anhydrous ethanol, and then fully stirred and mixed with AuNPs solutions of different amounts to form a zirconium-based MOF-808 / AuNPs solution; and in the fourth step, the zirconium-based MOF-808 / AuNPs solution is poured into sample boxes containing silicon substrates, and the silicon substrates are immersed, and after drying, a SERS substrate of the zirconium-based MOF-808 / AuNPs is obtained. The method has the advantages of simple preparation process, low cost, good uniformity of the prepared substrate, good signal repeatability, high sensitivity, good structural stability and the like.

The application belongs to the technical field of fluorescent probe detection, and discloses a bimetallic nanocluster fluorescent probe compound and application thereof in preparation of a product for rapidly detecting acetylene. The fluorescent probe compound is a gold-copper bimetallic nanocluster solution modified by adamantane thiol, which is used as a fluorescent probe for acetylene detection. The solution has a clear and controllable preparation process. Through specific proportioning and reaction conditions of cuprous chloride, adamantane thiol, tetrachloroauric acid, sodium borohydride and other reagents, a probe solution with stable fluorescence characteristics can be prepared. The bimetallic nanocluster fluorescent probe compound is applied in preparation of a product for rapidly detecting acetylene. Through specific combination of fluorescent molecules and acetylene gas to trigger the secondary effect of fluorescence quenching, detection is realized, and other substances cannot trigger quenching. At a wavelength of 700 nm, the linear relationship (R 2 >0.99) between the fluorescence intensity and the acetylene concentration realizes accurate quantification of the acetylene concentration, and the minimum detection limit is 0.026 muL / L.

The invention provides a preparation method of high-sphericity gold powder, and relates to the technical field of nano material preparation. The preparation method comprises the following steps: sequentially adding a multi-ligand stabilizer solution and an acid solution into a chloroauric acid solution, and adjusting the pH value of a reaction system to 4.0-5.0 to obtain a solution A; then, quickly adding a dispersing agent solution into the solution A for first-stage mixing, and then, quickly adding a reducing agent solution for second-stage mixing; and then, a morphology optimizing agent solution is dropwise added into a reaction system, precipitates are collected after full reaction, and the high-sphericity-degree gold powder is obtained. According to the method, a multi-ligand stabilizer is added into a chloroauric acid solution, and accurate control over the morphology of the gold powder is achieved through competitive adsorption between ligands. On the basis, an acid solution is added into a chloroauric acid solution, morphology control over the gold powder is further consolidated, the pH value of the solution adjusted through the acid solution is acidic, the reduction rate is further decreased, and the gold powder is better in dispersity and more uniform in size.

The utility model discloses a chloroauric acid crystallization device which comprises a crystallization kettle and a driving motor, the bottom of a stirring piece is rotatably connected with the inner wall of the crystallization kettle through a rotating shaft, scrapers are fixedly connected to the two sides of the curved surface of a transmission column, and a water inlet device is arranged at the bottom of the driving motor. A cleaning device used in cooperation with the water inlet device is arranged at the top of the inner cavity of the crystallization kettle, a transmission assembly used in cooperation with the cleaning device is arranged at the top of the scraper, and a transmission gear ring used in cooperation with the transmission assembly is arranged at the top of the curved-surface inner wall of the crystallization kettle. According to the crystallization kettle, the water inlet device, the cleaning device and the transmission assembly are matched for use, so that the problems that after an existing crystallization kettle is used, residues usually appear on the inner wall of the crystallization kettle, the residues on the inner wall generally need to be manually removed, the process is time-consuming and high in labor intensity, and the use of the crystallization kettle is influenced are solved.

The invention belongs to the technical field of pyruvic acid biological detection, and relates to a pyruvic acid sensing chip of a Prussian blue nano frame / gold nano composite material. The method comprises the following steps: adding soluble metal salt containing ferricyanide ions into water; the method comprises the following steps: adding soluble ferric salt and a complexing agent into water, mixing, and carrying out hydrothermal synthesis reaction to obtain PB powder; adding PB powder into ethanol, adding ammonia water for reaction, mixing with conductive carbon paste to obtain nano printing paste, and printing the printing paste on a substrate to form a working electrode; the preparation method comprises the following steps: preparing a working electrode, drying the working electrode, placing the working electrode in a chloroauric acid solution for constant potential electrodeposition, mixing a PBS solution of pyruvate oxidase, a polylysine solution and an EDC solution, dropwise adding the mixture on the surface of the working electrode, and drying to obtain the pyruvic acid sensing chip. The obtained pyruvic acid sensor can reach the sensitivity of 50.42 [mu] A.mM <-1 >. Cm <-2 >, and is simple in preparation process and relatively low in cost.

The application provides a preparation method of gold powder for matching low-temperature co-fired ceramic, and submicron irregular gold powder is prepared in an aqueous solution of chloroauric acid through an oxidation-reduction method. In the preparation process, amino acid is used as a gold ion complexing agent and a pH buffer of a reaction solution, a small-molecule organic substance containing an imidazole functional group and having weak reduction is used as a reducing agent, and after the gold powder is washed with deionized water, ethanol is used to replace water in the powder, and the like, so that submicron irregular gold powder which is not agglomerated is prepared. The gold powder prepared by the application has a particle size range of 200nm-900nm, has good dispersibility in alcohol and ester solvents, and after sintering, a film layer is dense, can be matched with various green ceramic materials at home and abroad, and after sintering, a substrate is flat and has a warping degree less than 0.1mm. The preparation method of the application has high yield and is convenient in the preparation process.

The invention discloses a high-thickness-diameter-ratio ultrathin gold nanosheet and a synthesis method thereof, and belongs to the technical field of micro-nano materials. According to the invention, a phytic acid reagent aqueous solution and a humic acid reagent aqueous solution are added into a chloroauric acid aqueous solution, wherein the phytic acid reagent and the humic acid reagent play roles of a reducing agent and a protective agent. Nucleation and growth of the ultrathin gold nanosheet with the high thickness-diameter ratio are achieved by regulating and controlling the reaction temperature, the pH value of the chloroauric acid water solution, the concentration of the phytic acid reagent water solution, the concentration of the humic acid reagent water solution and the like. The diameter of the synthesized ultrathin gold nanosheet with the high thickness-diameter ratio is 10-50 microns, the thickness of the nanosheet is 5-10 nm, and the slicing rate is larger than 90%; wherein a small amount of spherical gold particles exist, and the particle size of the spherical gold particles is 0.1-0.5 mu m. According to the method, phytic acid and humic acid biomass reagents are used for synthesizing the ultrathin gold nanosheets with the high thickness-diameter ratio, pollution of toxic reducing agents or surfactants to the environment is reduced, multi-valued utilization of the phytic acid and humic acid biomass reagents is effectively improved, the whole process is simple and easy to operate, large-scale production can be achieved, and the method is suitable for industrial production. The material is expected to be applied to the fields of catalysis and high-reliability electronic devices.

The application provides a preparation method and application of a flexible electrochemical sensor and belongs to the technical field of electrochemical detection. The preparation method is as follows: first, polyurethane sponge is soaked in a conductive carbon paste dispersion solution to obtain a conductive support; second, the conductive support is soaked in an aqueous chloroauric acid solution for electrochemical deposition to obtain a gold nano-structure layer modified conductive support; third, the gold nano-structure layer modified conductive support is placed in a groove of a PDMS base, and the gold nano-structure layer modified conductive support is separated into a working area and a clamping area by pouring PDMS to obtain a working electrode; and finally, a flexible electrochemical sensor is assembled. The flexible electrochemical sensor is used for hydrogen peroxide detection and has good biocompatibility, excellent tensile properties and stable electrochemical sensing performance.

The invention discloses a colorimetric detection method for cMyBP-C protein based on nano-enzyme activity, preparation of a bismuth selenide / nano-gold composite material and application of the bismuth selenide / nano-gold composite material in protein detection. The method comprises the following steps: performing ultrasonic stripping on a bismuth selenide block to obtain a few-layer bismuth selenide dispersion liquid; and then sequentially adding a sodium borohydride aqueous solution and a chloroauric acid aqueous solution under a stirring condition, and carrying out in-situ reduction to form gold nanoparticles loaded on the surface of bismuth selenide. The composite material has the capability of catalyzing reduction of p-nitrophenol into p-aminophenol, and the color of the solution is changed from yellow to colorless. After the cMyBP-C antibody is modified on the surface of the composite material, the catalytic activity is inhibited; after a to-be-detected sample is added, the antibody and the protein are specifically combined to cause dissociation, and the catalytic activity is recovered. The cMyBP-C protein is quantitatively detected by observing the color change of the solution or monitoring the reduction of the ultraviolet absorbance at 400 nm.

The invention discloses a spiral chiral gold nanorod as well as a preparation method and application thereof, and the method comprises the following steps: (1) sequentially adding hexadecyl trimethyl ammonium bromide, cysteine and p-aminothiophenol into an anisotropic gold nanorod solution, uniformly mixing, and adsorbing; and (2) silver nitrate, chloroauric acid and ascorbic acid are added for a reaction, centrifugal dispersion is performed after the reaction is finished, and the spiral chiral gold nanorod is obtained. Dispersing the spiral chiral gold nanorod in an aqueous solution, adding phenylalanine enantiomer, dropwise adding on a clean glass slide after incubation is finished, and performing surface enhanced Raman spectroscopy test by using a Raman microscope after air drying. According to the invention, the broadband coverage of chiral response from visible light to near ultraviolet region is realized by accurately regulating and controlling the arrangement of interface molecules and the morphology of the nano structure.

The invention discloses a water-soluble Au: Ag2Te quantum dot as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing water-soluble Ag2Te quantum dots at normal temperature by taking glutathione as a stabilizer, silver nitrate as a silver source, sodium tellurite as a tellurium source and sodium borohydride as a reducing agent; and then, through a cation treatment technology, chloroauric acid is added, and the Au: Ag2Te quantum dot is successfully prepared. Compared with a traditional Ag2Te quantum dot, the preparation process adopts a water-soluble non-toxic reagent, inert gas protection is not needed, and operation is easy and convenient. The emission wavelength of the prepared quantum dot is 1080 nm, and the quantum dot belongs to an NIR II region silver quantum dot and is suitable for in-vivo imaging of a living body; when the pH value ranges from 5 to 12, the fluorescence intensity and the pH value are in a linear relation, and the fluorescent probe can be used for monitoring the pH value. The quantum dot is environment-friendly and safe in preparation process and diversified in function, and a new reference is provided for the field of biomedicine.

This invention discloses gold nanoparticle-modified metal oxide framework materials, their preparation methods, and applications, relating to the fields of material preparation and detection technology. The preparation method of the gold nanoparticle-modified metal oxide framework material includes: in-situ reduction of chloroauric acid on the surface of ZIF-67 via a reduction method to obtain an Au / ZIF-67 composite material; and calcination of the Au / ZIF-67 composite material using a programmed temperature rise process to obtain the final product. This invention also provides applications of this material in serum metabolite detection and in screening metabolic biomarkers for esophageal cancer diagnosis. The composite material prepared by this invention possesses a unique hollow porous structure and uniformly distributed gold nanoparticles, providing a large specific surface area for enriching metabolites in serum. It also enhances the ultraviolet absorption and photothermal conversion efficiency of the nanocomposite material, while improving the material's conductivity, thereby significantly improving laser desorption / ionization efficiency and achieving high-sensitivity detection.

The invention relates to a pyridine compound modified CuAu bimetallic nano hollow structure catalyst, and preparation and application thereof, and belongs to the technical field of electro-catalysis. The preparation method comprises the following steps: dropwise adding a chloroauric acid solution into hollow Cu2O nano-particles to obtain a core-shell structure with gold nano-particles loaded on the surfaces of the hollow Cu2O nano-particles, then carrying out solvothermal reaction to obtain hollow CuAu nano-particles, and then adding a pyridine organic modifier to obtain the hollow CuAu nano-particles. The catalyst prepared by the invention has a Cu < + > / Cu0 at Au functionalized catalytic interface, realizes differential adsorption of * CO intermediates and subsequent hydrogenation reaction process, and promotes asymmetric * CO-* CHO coupling, so that the activity and selectivity of ethanol products are remarkably improved, and the Faraday efficiency can reach 76%.

This invention belongs to the field of biosensing technology, specifically relating to a modified carbon fiber electrode for detecting dopamine, its preparation method, and its application. The modified carbon fiber electrode comprises a carbon fiber electrode onto which gold-platinum bimetallic nanoparticles and polydopamine are sequentially modified. The preparation method specifically includes: firstly, modifying the surface of activated carbon fiber filaments with chloroauric acid and sodium citrate to obtain Au@CF; then, modifying the Au@CF surface with ascorbic acid and chloroplatinic acid to obtain platinum nanoparticles, obtaining Au / Pt@CF; finally, immersing the Au / Pt@CF in a dopamine solution to coat the Au / Pt@CF surface with polydopamine, obtaining PDA@Au / Pt@CF. This electrode has advantages such as high sensitivity, low detection limit, strong anti-interference ability, good biocompatibility, and high mechanical stability, making it suitable for dynamic monitoring of dopamine in the living brain.

The application discloses a kind of ratio fluorescent sensor based on smart phone and its preparation method and application, the preparation method includes: after mixing chloroauric acid, bovine serum albumin, sodium hydroxide, gold cluster reaction liquid is obtained;Sodium citrate, 3-aminopropyl triethoxysilane, glycerol are mixed to obtain silicon quantum dot solution;Silicon quantum dot solution, lipopolysaccharide aptamer, EDC, NHS are reacted in ultrapure water to obtain aptamer modified silicon quantum dots;Lipopolysaccharide aptamer modified silicon quantum dots and gold cluster are mixed to obtain ratio fluorescent sensor.The ratio fluorescent sensor based on smart phone prepared by the application has good stability, strong specificity, can exclude fluorescent interference in environmental matrix, and is used for lipopolysaccharide analysis and detection by combining the colorimetric analysis of color picker of smart phone, so that in-vitro naked-eye visible rapid quantitative detection of lipopolysaccharide can be realized, to meet the demand of on-site monitoring.

This invention discloses a photoelectrocatalyst and its preparation method, wherein the photoelectrocatalyst comprises Zn 2+ Ce 4+ Au; Zn 2+ Including ammonium acetate, zinc nitrate, and hexamethylenetetramine; Ce 4+ Including cerium nitrate, ammonium chloride, and potassium chloride; Au includes PVP, sodium citrate, potassium bromide, and chloroauric acid; Zn 2+ Ce 4+ The molar ratio of Au to Zn is... 2+ Ce 4+ Au = 1:0.5 ~ 1:2.5 * 10 ‑7 ~7.5*10 ‑7 This method uses electrodeposition to prepare ZnO as a substrate. Its vertically aligned one-dimensional (1D) nanostructures exhibit quantum size-dependent effects, effectively shortening the carrier diffusion distance. CeO2 coats the ZnO, forming a stable, acid- and alkali-resistant substrate material. CeO2 traps electrons from Ce... 4+ Restored to Ce 3+ This forms oxygen voids and Ce 3+ / Ce 4+ Electron pairs produce high catalytic activity.

The application provides a gold nanoflower enhanced flavonoid compound and a preparation method and application thereof, and the preparation method comprises the following steps: (1) mixing chloroauric acid, ascorbic acid, a protective agent and water to obtain a gold nanoflower solution; (2) mixing the gold nanoflower solution obtained in the step (1) with a flavonoid compound solution to obtain a gold nanoflower-flavonoid compound complex solution; and (3) mixing the gold nanoflower-flavonoid compound complex solution obtained in the step (2) with a biotin-PEG-SH solution to obtain the gold nanoflower enhanced flavonoid compound. The gold nanoflower enhanced flavonoid compound provided by the application effectively enhances the fluorescence intensity of a flavonoid traditional Chinese medicine small molecule at a tumor site, provides a more accurate and clear tumor image, and has the advantages of good targeting effect.

This invention relates to a near-infrared low-potential electrochemiluminescence dual-ligand stabilized gold nanoclusters, their preparation method, and applications. The method uses chloroauric acid as the gold source and thiomalic acid and sodium citrate as reducing and stabilizing agents, respectively, in a two-step synthesis. First, Au is reduced online using thiomalic acid. 3+ Water-soluble gold nanoclusters were prepared using a novel method. These nanoclusters were then incubated with sodium citrate, and based on the ligand exchange principle, gold nanoclusters co-coated with thiomalic acid and sodium citrate were synthesized. The raw materials required for this invention are readily available and all possess good water solubility. The synthesis apparatus is simple, the conditions are mild, and the operation is safe. The resulting dual-ligand-coated gold nanoclusters exhibit good stability and produce low-potential near-infrared electrochemiluminescence in the long-wavelength region in an aqueous system. This overcomes the limitation of most current electrochemiluminescent materials requiring hydrazine hydrate or carbazide as a co-reactant. Using a non-toxic tert-butylamine-borane co-reactant, low-potential electrochemiluminescence radiation of 0.57V in the near-infrared region was generated.

The invention discloses a preparation method of silicon dioxide-gold core-shell nanoparticles, and belongs to the field of nano material preparation. The method comprises the following steps: preparing aminated silicon dioxide nanoparticles; preparing small gold nanocrystal seeds and adsorbing the small gold nanocrystal seeds on the surface of silicon dioxide; ascorbic acid or a salt thereof is used as a weak reducing agent, a chloroauric acid solution is slowly added, uniform growth of a gold shell is induced on the surface of a gold seed, and finally a complete core-shell structure is formed. According to the method, surface modification and adsorption are optimized, a weak reduction growth system is adopted, and growth kinetics is accurately controlled, so that the problems of uneven gold shell coating, complex process and poor reproducibility in a traditional method are effectively solved. The nanoparticles prepared by the method have the advantages of complete and smooth gold shell, accurate and controllable thickness (5-50nm), adjustable plasma resonance absorption, good monodispersity and the like, and have important application value in the fields of biomedicine and photoelectricity.

The invention belongs to the field of preparation of organic-inorganic hybrid materials, and relates to a preparation method and application of cucurbit [n] uril-gold nanoparticles. Through a simple one-pot synthesis method, chloroauric acid, silver nitrate, a reducing agent and cucurbit [n] uril are added for co-reduction to prepare hollow gold nanoflowers; the gold nanospheres with different sizes are prepared by regulating and controlling the input amount of cucurbit [n] uril. The gold nanoparticle hybrid material shows excellent hydrogen evolution side reaction inhibition capability in the application of electro-catalysis CO2 reduction, and the CO selectivity is obviously improved.

The application discloses a Raman enhancer and a preparation method and application thereof, and adopts an improved trisodium citrate reduction chloroauric acid method to prepare dopamine carbon dot modified gold nano Raman enhancer by taking dopamine carbon dot as a reducing agent and a stabilizer. When the Raman enhancer is used for detecting imazalil residues in tobacco, the dopamine carbon dot modified gold nano Raman enhancer is prepared, a linear relationship between the imazalil concentration and the peak area of a quantitative characteristic peak is established, and the surface enhanced Raman spectrum of the imazalil in the tobacco sample is detected. The dopamine carbon dot is synthesized for the first time, the dopamine carbon dot is introduced into the preparation of the gold nano Raman enhancer for the first time and is used as a reducing agent and a stabilizer, trisodium citrate is used as a reducing agent to reduce chloroauric acid, and a new method for synthesizing the gold nano Raman enhancer is provided. The gold nano has a remarkable Raman enhancement effect and the stability is remarkably enhanced. The gold nano can be stored in a refrigerator for more than half a year without agglomeration, can be stored at room temperature for a short period of time, and the storage does not affect the enhancement effect.

The invention belongs to the technical field of uric acid detection, and relates to a preparation method and application of a uric acid and pH dual-electrode detection sensor. The preparation method comprises the following steps: mixing a soluble manganese salt with a complexing agent, adding a soluble hexacyanoferrate solution, aging and standing at room temperature, centrifuging, drying, and pyrolyzing at high temperature to obtain the Mn2O3 / Fe2O3 material. Coating on the surface of a first working electrode, and then continuously dropwise adding a mixed solution containing a cross-linking agent and urate oxidase; and uniformly mixing a chloroauric acid solution with a hydrochloric acid solution and an aniline solution with a hydrochloric acid solution, carrying out electro-deposition on a second working electrode, and drying at low temperature to obtain the sensor. The sensor designed based on the double working electrodes shows excellent stability, reproducibility and anti-interference performance in sweat uric acid monitoring. The sensor can realize rapid identification and dynamic response of uric acid in a real sweat sample, and is expected to be used for integration of wearable equipment to realize continuous gout early warning.

The invention discloses a method for green synthesis of gold micron sheets by using xylan in cooperation with chloroauric acid, and belongs to the technical field of micro-nano materials. A green and environment-friendly biomass reagent xylan is used for synthesizing the gold micron sheet in a water phase system, and the specific preparation method comprises the steps that a polyvinylpyrrolidone solution is added into a chloroauric acid solution, xylan is added to serve as a reducing agent and a protective agent, and the gold micron sheet is obtained; effective nucleation and growth of the gold micron sheet are achieved by regulating and controlling the reaction temperature, the reactant mass concentration and the pH value of the gold precursor solution. The synthesized gold micron sheet is hexagonal, triangular and truncated triangular, the diameter is 1-6 microns, the sheet thickness is 100-150 nm, the sheet rate is higher than 80%, and the particle size of a small number of spheroidic gold particles is 0.1-1 micron. According to the method, the biomass reagent xylan is used, pollution of traditional chemical reagents to the environment is relieved, operation is easy and convenient, large-scale production is easy, the size and shape of the gold micron sheet are controllable, and an efficient method is provided for green synthesis of the gold micron sheet.

The invention provides a preparation method and application of a high-sensitivity and high-uniformity SERS (Surface Enhanced Raman Scattering) substrate, and belongs to the technical field of preparation of Raman substrates. According to the method, a two-dimensional material with electron donor characteristics is creatively adopted as a medium substrate, uniform metal quantum dots are generated on the surface of the medium substrate in situ through reaction of the medium substrate and a chloroauric acid solution, pores in the range of sub-nanometer to 10 nm exist between the metal QDs, and the metal QDs are separated from the medium substrate. Therefore, the preparation of the Raman substrate with high sensitivity and high signal uniformity is realized. The Raman substrate prepared by the invention has extremely high signal uniformity (RSD is approximately equal to 4.0%), realizes large-area repetitive enhanced output while keeping an ultra-low detection limit (up to 10 <-18 > mol / L), and is suitable for rapid recognition and quantitative analysis of trace molecules.

The application discloses a micro electrochemical sensor for detecting amyloid polypeptide A beta 1‑42 and a preparation method and application thereof. The preparation method comprises the following steps: taking an acupuncture needle as a bare electrode, sequentially modifying tetrachloroauric acid trihydrate-gold nanoparticles, single-wall carbon nanotubes, hemin, amyloid polypeptide A beta 1‑42 template molecules, mixed polydopamine and ion liquid to form an imprinting polymer, and then eluting to obtain the micro electrochemical sensor ANME / / hemin / / SMIP electrode. The micro electrochemical sensor can be used for high-sensitivity detection of amyloid polypeptide A beta 1‑42 , and realizes specific detection of amyloid polypeptide A beta 1‑42 .