362 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 belongs to the technical field of electro-catalysis, and particularly relates to a one-pot preparation method of a high-alloying gold-silver alloy aerogel material and application of the high-alloying gold-silver alloy aerogel material in electro-catalytic reduction of CO2. According to the preparation method, chloroauric acid and silver nitrate are selected as precursors for synthesizing the AuAg alloy aerogel, the AuAg alloy aerogel is prepared through a simple one-pot preparation method, and complex processes such as ultrafiltration centrifugal purification and concentration and heat treatment are not needed. Compared with an existing two-step method, the preparation process is complex, time and labor are consumed, and heat treatment is needed. However, according to the one-pot preparation method used in the invention, the high-alloying AuAg alloy aerogel can be obtained only by simply feeding, stirring and standing at room temperature. Moreover, the alloying degree of the obtained AuAg aerogel is higher, higher CO selectivity is shown in CO2RR application, and compared with AuAg alloy aerogel obtained through an existing two-step method, the CO Faraday efficiency of the AuAg aerogel is improved by about 37.1%.

The invention provides a preparation method of an organ-shaped MXene and one-dimensional WO3 nanorod nano self-reduction growth Au nanoparticle NO2 gas-sensitive composite material. The preparation method comprises the following specific steps: (1) preparing a high-molecular flexible substrate; (2) preparation of organ-shaped MXene; (3) preparing an MXene / WO3 composite material; and (4) preparation of an MXene / WO3 / Au composite material: the adding mass of accordion-shaped MXene is 5-160 mg, the adding amount of tetrachloroauric acid (HAuCl4. 3H2O) is 30 [mu] L, the product obtained by reaction is the MXene / WO3 / Au composite material, and the flexible substrate on which the composite gas sensitive material is deposited is the prepared NO2 sensor. The organ-shaped MXene and one-dimensional WO3 nanorod self-reduction growth Au nanoparticle NO2 gas-sensitive composite material prepared by the invention has a uniformly dispersed composite structure, the introduction of the organ-shaped MXene effectively improves the conductivity of WO3, and meanwhile, rich functional groups on the surface of the composite material contribute to improving the gas-sensitive property of WO3. Different electrodes can be deposited on the flexible substrate, the cost is low, the steps are simple and controllable, the flexibility is good, the sensitivity is high, and NO2 detection can be realized at room temperature.

The invention provides high-permeability colorimetric hydrogel for detecting the content of glucose in sweat and a preparation method of the high-permeability colorimetric hydrogel, and relates to the technical field of wearable colorimetric sensing. The preparation method of the high-permeability colorimetric hydrogel comprises the following steps: mixing polyoxyethylene polyoxypropylene ether, chloroplatinic acid, chloroauric acid and water, and then adding L-ascorbic acid for reaction to obtain gold-platinum nanocrystalline dendrites; the preparation method comprises the following steps: mixing polyvinyl alcohol, 3, 3 ', 5, 5'-tetramethyl benzidine, gold-platinum nanocrystalline dendrites, ethylene glycol and water to obtain a hydrogel precursor solution, and curing the hydrogel precursor solution to obtain a hydrogel precursor; and soaking the hydrogel precursor in a sodium chloride solution to obtain the high-permeability colorimetric hydrogel for detecting the content of glucose in sweat. The gold-platinum nanocrystal dendrite nanoenzyme has tandem bio-enzyme activity, glucose oxidase activity and peroxidase double-enzyme activity, and TMB is used as a chromogenic substrate to prepare the hydrogel, so that colorimetric detection of glucose can be realized.

The invention discloses a preparation method of nanorods, micro-nano particles and flaky mixed gold powder. The preparation method comprises the following steps: (1) taking ethylene glycol, high-purity water or a mixed solution of ethylene glycol and high-purity water as a solution a; (2) dissolving chloroauric acid in the solution a to obtain a solution b; (3) dissolving disodium ethylene diamine tetraacetate in the solution b to obtain a solution c; (4) dissolving polyvinylpyrrolidone in the solution c to obtain a solution d; (5) dissolving a reducing agent in the solution d to obtain a solution e; (6) adding sodium hydroxide into the solution e to obtain a solution f; (7) transferring the solution f into a polytetrafluoroethylene liner, and then performing hydrothermal reaction to prepare gold powder; and (8) washing, separating and drying the gold powder to prepare the gold powder with different shapes and sizes. The preparation method is simple, high-cost equipment is not needed, the batch morphology of the product is stable, and large-scale low-cost preparation of the gold powder is facilitated.

The invention discloses a preparation method of a full-spectrum response plasmon photocatalyst for reducing carbon dioxide to prepare methane, and belongs to the technical field of photocatalytic reduction of CO2. Tungsten hexacarbonyl and silver nitrate, nickel chloride or chloroauric acid are used as raw materials, and a solvothermal reaction is performed to obtain a plasmon W18O49 nanowire photocatalyst doped with different metal ions. According to the preparation method for preparing the CH4 plasmon photocatalyst through full-spectrum response CO2 reduction, the prepared Au, Ag or N metal ion doped plasmon W18O49 nanowires have high ultraviolet-visible-near infrared light absorption capacity and rich surface oxygen vacancy concentration, adsorption and activation of CO2 molecules are facilitated, meanwhile, the surface oxygen vacancy concentration is increased, and meanwhile, the surface oxygen vacancy concentration is increased. The surface of the catalyst can effectively stabilize a * CO intermediate generated in the photocatalytic CO2 reduction process, and the performance and selectivity of the original plasmon W18O49 for preparing CH4 through photocatalytic CO2 reduction are remarkably improved.

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 discloses a gold-silver alloy nanoprobe based on double-signal cooperative detection, a preparation method and application thereof, and belongs to the technical field of sensing. Then mixing the gold nanorod, a Raman report molecule p-methylthiobenzonitrile and a chiral stimulating factor L-cysteine, and jointly incubating at room temperature to obtain a mixed solution; sequentially adding silver nitrate, chloroauric acid tetrahydrate and ascorbic acid into the mixed solution, and magnetically stirring; and placing the mixed solution under a constant temperature condition to react for a certain time, so that the gold-silver alloy shell fully grows, and finally obtaining the spiral structure alloy nanoprobe with Raman signals and CD signals. The probe realizes the dual detection functions of Raman signals and circular dichroism signals, and can detect the lactic acid concentration with high sensitivity and high selectivity by combining the specific catalytic action of the lactate oxidase, and meanwhile, the Raman signals and CD signals of the silent zone can further expand the application range of the probe.

The invention belongs to the field of biosensor detection, and particularly discloses a colorimetric detection method based on functionalized copper cysteine nano-enzyme, which comprises the following steps: preparing a specific functionalized copper cysteine nano-enzyme composite material; and constructing a detection reaction system containing hydrogen peroxide, tetramethyl benzidine, an acetate buffer solution and a target solution, and determining the concentration of the target by using a colorimetric analysis technology. Particularly, CuCl2. 2H2O is used as a copper source, PEG-4000 is used as polyethylene glycol, reaction is performed under nitrogen protection and alkalescence conditions, and then the reaction product reacts with chloroauric acid and trisodium citrate to prepare the composite material. According to the method, hydrogen peroxide and tetramethyl benzidine are taken as substrates, high-sensitivity detection of a target object (such as dopamine) is realized by measuring an absorption peak value of a reaction system at 652nm, and a standard curve is drawn so as to accurately measure the concentration of a solution to be measured. The method is simple and convenient to operate and high in sensitivity, and has a wide application prospect in detection of biological molecules such as dopamine.

The invention relates to a preparation method and application of an AuPd alloy nanoparticle doped ZnO sensing material, and belongs to the field of gas sensing. According to the invention, sodium hydroxide is used as a solution to provide an alkaline environment, zinc nitrate hexahydrate is used as a zinc source, chloroauric acid and palladium chloride are used as a gold source and a palladium source, deionized water is used as a solvent, and the AuPd-ZnO gas-sensitive sensing material is prepared through the steps of mechanical stirring, microwave-assisted hydrothermal method synthesis, centrifugation, drying and the like. The sensor based on the AuPd-doped ZnO nano material has good gas-sensitive performance on acetone, and has high response, ideal stability and good selectivity. The response to 50 ppm ethanol is 32, the lower limit of detection is 5 ppm, and high stability is shown in a continuous peripheral gas-sensitive test. The method is simple in preparation process, low in equipment requirement and high in controllable degree, and the obtained product is uniform, has excellent gas-sensitive performance, can realize trace detection of ethanol and can be used as an ideal sensing device for ethanol detection.

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 belongs to the field of catalytic materials, and particularly discloses a double noble metal supported molecular sieve catalyst for catalyzing oxygen to oxidize methane to prepare acetic acid. The preparation method comprises the following steps: mixing a chloroauric acid solution and another noble metal chloride solution as precursors with a molecular sieve, adjusting a certain pH value, stirring and aging at a proper water bath temperature for a certain time, and then filtering, drying and calcining to obtain the catalyst. According to the catalyst, a molecular sieve is used as a carrier, gold is used as an oxidation active center, carbon-carbon coupling is achieved with another precious metal, high-selectivity acetic acid preparation through methane pure oxygen direct oxidation can be achieved under the mild condition of 120-240 DEG C, and the selectivity reaches up to 97.2%. The catalyst preparation method adopted by the invention is simple in process, green and pollution-free, high in noble metal loading efficiency, low in price and easy for expanded production, and provides a thought for developing and preparing a high-efficiency catalyst for direct selective oxidation of methane under mild conditions.

The invention discloses an Au7Cu10 nanocluster and a preparation method and application thereof.The preparation method comprises the following steps that chloroauric acid and cuprous chloride serve as a gold source and a copper source respectively and are dissolved and stirred in a solvent, 1-adamantanethiol is added, and the color of the solution is changed into dark green from yellow; continuously adding diphenyl-2-pyridine phosphine to enable the color of the solution to be changed from dark green to light orange, continuously adding a mixed solution of sodium borohydride and ice water, and isolating air to enable the color of the solution to be quickly changed into black; and centrifuging to remove a water phase, evaporating an organic phase, washing black precipitate, recrystallizing a crude product at low temperature, and culturing to obtain the Au7Cu10 nanocluster. The Au7Cu10 nanocluster disclosed by the invention shows excellent performance, so that the Au7Cu10 nanocluster has the potential of serving as molecular triplet energy and an electronic substitute in optoelectronics, photocatalysis and solar energy conversion.

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 invention relates to a nanogold aggregate capable of realizing kidney excretion, a preparation method and application of the nanogold aggregate as a CT contrast agent, and the preparation method comprises the following steps: mixing a chloroauric acid solution, an alkali solution and a sulfydryl hydrophilic compound to obtain a mixed solution A; under the ice-water bath and stirring conditions, a reducing agent is added into the mixed solution A, and a mixed solution B containing nano-gold particles is obtained; mixing the mixed solution B with a wrapping material-buffer solution to obtain a mixed solution C containing the gold nanoparticles and the wrapping material; adding a positively charged compound solution into the mixed solution C to obtain a mixed solution D; the nanogold becomes a stable aggregate through a positively charged compound; and centrifuging the mixed solution D to obtain the nanogold aggregate capable of realizing kidney excretion. The synthesized ultra-small nanogold is agglomerated into the nanogold aggregate with a stable structure, the contrast agent can be obtained through simple centrifugal concentration, the contrast agent is stable in property and good in biocompatibility, and the contrast agent can be discharged out of a body along with urine within a period of time after entering the body.

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 invention relates to the technical field of nano enzymes, and discloses a preparation method of a black phosphorus-gold nano composite material based on ice bath and ultrasonic exfoliation, which comprises the following steps: step 1, preparing BP sheets: dispersing BP powder in deoxygenated water, and carrying out ultrasonic exfoliation under an ice-water bath condition; carrying out gradient centrifugal separation, and collecting precipitates; carrying out freeze drying to obtain BP nanosheets, and dispersing the BP nanosheets to obtain a BP nanosheet dispersion liquid; step 2, preparation of a composite material: adding a surfactant and a chloroauric acid solution, and performing ultrasonic mixing under a protective atmosphere; and then dropwise adding a NaBH4 aqueous solution, and washing to obtain the composite material. Through cooperation of the black phosphorus nanosheet and the gold nanoparticles, the gold nanoparticles are loaded on the surface of the black phosphorus nanosheet, and the stability of the black phosphorus nanosheet is improved by the gold nanoparticles, so that the composite material has a relatively high photothermal conversion rate, and the composite material has a better photothermal effect than single black phosphorus, thereby realizing photothermal therapy.

The invention discloses a ferroferric oxide, gold, internal label and gold core-shell nanoparticle and a preparation method thereof. Ferroferric oxide is used as a main body, nano-particles which take 16-20 nm gold nano-particles as cores, take sulfydryl molecules with benzene rings as internal standards and have the gold shell thickness of 35-40 nm are adsorbed on the surface of the ferroferric oxide, the overall particle size of the ferroferric oxide nano-particles is 200-460 nm, and the particle size of ferroferric oxide balls is 160-400 nm; the method comprises the following steps: uniformly dissolving ferric chloride, sodium acetate and polyethylene glycol in ethylene glycol according to a mass ratio of (1-2.7): (0.15-0.72): (0.5-2.3), heating to 200 DEG C, keeping the temperature for 8-72 hours, and naturally cooling to room temperature; and putting the product into a drying box, and drying at 60 DEG C. The method comprises the following steps: firstly, preparing Fe3O4 nano-particles, then carrying out surface modification on the Fe3O4 nano-particles, adsorbing 16nm gold seeds to the surfaces of the Fe3O4 nano-particles, adding internal standard molecules, and finally adding ascorbic acid and chloroauric acid to realize gold shell growth on the surfaces of the 16nm gold seeds. The material has the advantages of magnetic aggregation, easiness in separation and the like, and can be applied to the fields of pesticide residue detection, catalytic degradation, environment detection and analysis and the like based on an SERS (Surface Enhanced Raman Scattering) technology.

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 present invention discloses a preparation method of an aptamer photoelectrochemical sensor for detecting toxins in food, comprising the steps of: dripping a TiO2 dispersion on the surface of an ITO conductive glass electrode, adding a chloroauric acid solution for electrodeposition after drying; modifying the electrode surface after deposition with a toxin aptamer in food for incubation, drying with nitrogen to obtain an apt / Au / TiO2 / ITO electrode, incubating the apt / Au / TiO2 / ITO electrode surface with 6-mercaptohexanol as a blocking agent, and drying to obtain a working electrode; using a saturated TiO2 solution as an electrolyte to obtain an aptamer photoelectrochemical sensor for detecting toxins in food. The preparation method can accurately detect the toxin concentration in food. The present invention also provides an aptamer photoelectrochemical sensor prepared by the method, and an application of the aptamer photoelectrochemical sensor in mycin analysis and detection.

The invention belongs to the technical field of food safety and quality detection, and provides a method for detecting lycopene content by paper-based surface enhanced Raman. The method comprises the following steps: reacting chloroauric acid with sodium citrate to obtain a gold nano solution, and carrying out centrifugal concentration on the gold nano solution to obtain a concentrated gold nano solution; mixing a lycopene-containing solution to be detected with the concentrated gold nano solution to obtain a sample solution; dipping the paper tip substrate in a sample solution, sequentially performing drying and lycopene Raman signal detection after dipping, and obtaining the content of lycopene in the to-be-detected solution according to a Raman signal detection result, the preparation method of the paper tip substrate comprises the following steps: sequentially cutting filter paper and sealing the filter paper with wax oil to obtain the paper tip substrate. The method not only can give full play to the advantages of the SERS technology, but also has the characteristics of high detection precision, high detection speed, good detection stability and repeatability and low detection cost, and is beneficial to wide application in the field of rapid detection.

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.

This application belongs to the technical field of functional nanomaterials, and particularly relates to an AuM nanoflower, a green, efficient and low-cost preparation method thereof, and an application thereof. The green, efficient and low-cost preparation method of the AuM nanoflower provided by this application incubates chloroauric acid trihydrate and a water-soluble compound of at least one noble metal in a green tea aqueous solution to obtain the AuM nanoflower. The raw materials used in the preparation method are easy to obtain, the process is simple, the operation is convenient, the universality is strong, and the repeatability is high. It has a high yield, low cost and environmental friendliness, and the product AuM nanoflower has adjustable size and composition, high purity and good dispersibility, thus solving the technical problem of the lack of a green synthesis method for noble metal alloy nanoflower structures in the prior art.

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.