900 results about "Chlorauric acid" patented technology

The invention discloses a preparation method of magnetic / gold nano particles. The preparation method comprises the following steps: firstly adopting a co-precipitation method to prepare the magnetic Fe3O4 nano particles; polymerizing the dopamine in-situ on the surfaces of the magnetic particles to obtain Fe3O4 nano particles modified by the poly dopamine; introducing polyphenol and amino groups to the surfaces of the Fe3O4 nano particles; absorbing the nano gold seeds on the surfaces of the modified magnetic particles through the static action; adopting the nano gold which is absorbed on the surfaces of the magnetic particles as the seed, adopting the polyphenol on the surfaces of the magnetic particles as a reducing agent, gradually adding the chloroauric acid liquid to gradually produce the gold layers on the surfaces of the magnetic particles to obtain the core-shell magnetic / gold nano particles. The nano particles have good water dispersion and strong magnetic respond performance. The diameters of the nano particles are 30-100 nanometers, the saturation magnetization is 30.1-38.7emu / g, and the nano particles are superparamagnetic. The nano particles have wide application prospect on the fields of targeted drug controlled release, thermal therapy, separation of protein and enzyme, etc.

The invention discloses a method for preparing cauliflower nano gold-silver alloy with a surface-enhanced Raman scattering activity, which comprises: mixing 0.001mol / L solution of silver nitrate and 0.001mol / L solution of sodium phytate in a volume ratio of 30:1; heating the mixed solution till the mixed solution boils and keeping the temperature between 90 and 100 DEG C; adding 1 percent solution of trisodium citrate in an amount which is one fiftieth of the volume of the solution of silver nitrate to perform an reaction at 90 to 100 DEG C for 3 hours to prepare nano silver cluster dispersion stabilized by phytic acid; and transferring 12 to 17 milliliters of dispersion into a 25 milliliter beaker, heating the solution to 45 to 65 DEG C with stirring, slowing dripping 1.5 to 2.4 millimeters of 0.01 mol / L solution of chloroauric acid and stirring the mixed solution for 25 to 35 minutes to obtain a sample. The obtained cauliflower nano gold-silver alloy nanoparticles can keep stable for more than 6 months and has high signal repeatability and a surface-enhanced Raman effect. The preparation method is simple and low in cost.

The invention discloses a method for preparing size-controlled gold nanostars with surface Raman enhanced activity, belonging to the technical field of material chemistry. The method is characterized by comprising the steps of synthesizing nanomaterials with the surface Raman enhanced activity through a seed-mediated growth method, wherein the nanomaterials are gold nanostars; taking polyvinylpyrrolidone as seed liquid for stabilizer-coated gold nanoparticles; and reducing chloroauric acid adsorbed on the surface of the gold nanoparticles by using the reducing capacity of polyvinylpyrrolidone, so that the nanoparticles further grow in a crystal form direction, thereby obtaining gold nanostar particles with different forms; and meanwhile, gold nanostar materials with different surface enhanced Raman scattering (SERS) activities and different particle sizes can be obtained by changing the proportion of the reaction. According to the method, the gold nanostars with the uniform form and the relatively high yield can be prepared.

The invention discloses a carbon quantum dot / aurum cluster ratiometric fluorescent probe for detection of cadmium ion and ascorbic acid. A preparation method comprises the following steps: preparing CQDs (Carbon Quantum Dots) from alanine and histidine through a one-step hydrothermal method; performing amino-functionalization on the CQDs by using 3-aminopropyltriethoxysilane, wherein the CQDs which are subjected to the amino-functionalization serve as a reference chromophore; reducing chloroauric acid through sodium borohydride by taking 11-sulfydryl undecanoic acid as a surfactant to obtain MUA-modified AuNCs (Aurum Nano Clusters), wherein the MUA-modified AuNCs serve as a main fluorophore of the ratiometric fluorescent probe; finally, coupling the CQDs and the AuNCs through an amidation reaction to obtain the CQDs / AuNCs ratiometric fluorescent probe. On the basis of static quenching and inter-filtering effects, the fluorescence of the CQDs / AuNCs can be quenched by Cd<2+>; the invention discloses the application of the CQDs / AuNCs ratiometric fluorescent probe in Cd<2+> detection. The fluorescence of the CQDs / AuNCs which is quenched by the Cd<2+> can be recovered by the ascorbic acid, so that the ratiometric fluorescent probe can also be used for the detection of AA (Ascorbic Acid). The ratiometric fluorescent probe disclosed by the invention has the lower detection limit of 32.5 nM to the Cd<2+>, has the lower detection limit of 0.105 muM to the AA, and has an application value in the detection of the cadmium ion and the ascorbic acid.

The present invention discloses a microwave producing method for nano-silver or gold; the reactants are added into the reactor according to the proportion of 1 to 1; the reactants are silver nitrate or auric chloride acid and starch or sodium carboxymethyl cellulose; the reactor is put into a microwave oven; with a mixer of a rotation speed of 100 / min and the microwave power of 0.3 Kw, the reaction time of the reactant starch is one hour while the time of the reactant sodium carboxymethyl cellulose is seven hours; the solution is dried by air or vacuum freeze or spraying after the reaction is over to produce nano-silver or gold powder or concentrated to nano-silver or gold colloid of the needed consistency through vacuum concentration. The present invention discards the ordinary reducing agent in thermochemical synthesis and takes the microwave heating to replace the traditional local heating method and realize homogeneous growing of nano-silver or gold; the grain size distribution of the nano-silver and gold is narrow and the grain shapes are regular; the method is widely used in biochemical and antiseptic material field.

The invention provides a core-shell-structure silver-gold nanosheet based on epitaxial growth and a preparation method and application thereof. The method includes the steps that firstly, a silver nanosheet solution is prepared, then, chloroauric acid and ligand react in the alkaline environment, and a gold precursor solution is obtained; and a reducing agent, surfactant, a pH modifier, ligand or acetonitrile and the silver nanosheet solution are added to the gold precursor solution, and the core-shell-structure silver-gold nanosheet is obtained after the reaction. The ligand and chloroauric acid radial can generate coordination, a gold precursor is formed, the redox potential of gold is reduced, and the replacement reaction is prevented from being generated; the gold precursor is reduced into gold atoms through the reducing agent, the gold atoms are deposited on the surface layer of a silver nanosheet in an epitaxial growth mode, and the core-shell-structure silver-gold nanosheet is formed. The preparation process is simple and feasible; the shape and the size of the core-shell-structure silver-gold nanosheet are controllable; the excellent stability and the good optical property are achieved; wide application prospects are achieved in the fields of molecular detection and the like.

The invention relates to a gold nucleus and silver shell double-metal nanocrystal and a preparation method thereof. The crystal is in a rod-shaped structure with a regular crystalline form, wherein the rod-shaped structure is focused on a {100} surface and comprises a double-cube triangle, a cube and a five-twin crystal section, and simultaneously the side surface of the rod-shaped structure is a {100} type crystal surface. The preparation method comprises the following steps of: heating a polyhydroxy-alcohol solution containing chloroauric acid, polyvinylpyrrolidone and silver nitrate, cooling at a room temperature and carrying out centrifugal precipitation to obtain a gold crystal seed; and adding the gold crystal seed obtained by centrifugal separation to a polyhydroxy-alcohol solution containing the polyvinylpyrrolidone, adding the silver nitrate in a molar ratio [AgNO3] / [HuAuCl4], heating by using an oil bath to obtain a product solution, and then carrying out centrifugation to obtain a product. In the first step of reaction in the preparation method, a certain trace of silver nitrate is added to the solution so that the shape of a gold nucleus is effectively controlled, the crystal with a regular crystalline form is obtained, and the shape of a silver shell is finally decided on the shape of the gold seed. The preparation method realizes rapid and batch controllable preparation of a silver-coated gold nano nucleus / silver structure crystal forced on the {100} surface.

The invention relates to a preparation method of polystyrene / gold composite microspheres, which comprises the following steps: modifying polystyrene microspheres with a silane coupling agent, mixing with a chloroauric acid solution, and heating to carry out ionic selfassembly, wherein gold ions are fixed to the surface of the polystyrene microspheres through gold-nitrogen bonds; and after the solution is boiling, adding trisodium citrate to reduce the gold ions adsorbed onto the amino group in situ, thereby generating the core-shell structure in which a gold nanoparticle is coated on each polystyrene microsphere. The size of the gold particles and the coverage percentage of the gold particles on the polystyrene microspheres are controllable to some extent.

The invention relates to a preparation method for polydopamine-coated polyethyleneimine-stablized gold-nanometer-star photothermal treatment agent. The preparation method comprises the following steps: preparing a gold seed solution from chloroauric acid and sodium citrate; activating mercaptoacetic acid with EDC, then adding an aqueous PEI solution and carrying out a reaction, dialysis, cooling and drying so as to obtain PEI-SH; adding dopamine hydrochloride into a Tris buffer so as to obtain dopamine Tris buffer; adding the gold seed solution into a chloroauric acid solution, adding a AgNO3 solution and an ascorbic acid solution under stirring, adding PEI-SH after stirring reaction and carrying out a reaction so as to obtain AuNSs-PEI; and adding AuNSs-PEI into the dopamine Tris buffer and carrying out stirring and centrifugation so as to obtain the photothermal treatment agent. The preparation method has the advantages of simplicity, mild reaction conditions, easy operation and industrialization prospects; and the prepared star-like nanometer agent has application potential in the fields of CT imaging diagnosis and photothermal treatment of cancers.

The invention discloses a method for preparing functional gold nanoparticles with high stability, which belongs to the technical field of material chemistry. The method comprises the following steps of: the DNA-assisted synthesis of the gold nanoparticles, the salt tolerance experiment of the synthesized gold nanoparticles, the representation of the synthesized gold nanoparticles and the biometric identification of the DNA on the surfaces of the gold nanoparticles. In the method, four kinds of DNAs with three different lengths are utilized and a chloroauric acid is reduced by trisodium citrate to realize the assisted synthesis of the gold nanoparticles; the DNAs of 12 basic groups are obtained by performing representation with an electron microscope to assist in synthesizing the uniform spherical gold nanoparticles, and particularly, the gold nanoparticles obtained by the 12-G-assisted synthesis have regular shapes and a uniform particle size; the salt-tolerant effect of the gold nanoparticles obtained by the salt tolerance experiment of the synthesized gold nanoparticles can be bettered by 20 times; and the gold nanoparticles can enhance the fluorescence of FAM-DNA, and are expected to be well applied to the preparation of nanometer medicaments and nanodevices.

The invention discloses a method for preparing AuNPs (nanogold)-PDMS (polydimethylsiloxane) composite micro film surface stress biosensor. The method comprises the following steps: by taking a PDMS film as a substrate and using a chloroauric acid solution as a first-step reducing agent, reducing to generate a gold seed; by utilizing the gold seed generated on the film and taking glucose and potassium bicarbonate as auxiliary reducing agents, performing second-step reduction on the composite film by using the chloroauric acid; by utilizing an AuNPs-PDMS composite film as a sensitive element of the sensor and taking PDMS as a substrate, preparing a gold electrode of the sensor by adopting a sputtering technology, and finishing preparation of the sensor. The electric conductivity of the AuNPs-PDMS composite film generated by the method is obviously improved, so that the sensitivity of the sensor is improved. Moreover, the preparation method is simple, and possibility is provided for miniature, low-cost batch production.

The invention relates to a method for preparing a computed tomography (CT) / magnatic resonance imaging (MRI) bimodal imaging contrast agent based on dendrimers. The method comprises the following steps of: (1) adding DOTA-N-hydroxy succinimide (NHS) solution into the fifth generation of poly(amidoamine) (PAMAM) dendrimer solution, adding methoxy poly(ethylene glycol) (mPEG)-COOH solution which is subjected to 1-ethy 1-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) activation, reacting with stirring, and thus obtaining functionalized dendrimer solution; (2) adding chloroauric acid solution and sodium borohydride solution into the functionalized dendrimer solution, reacting with stirring, adding gadolinium nitrate solution, stirring, adding triethylamine and acetic anhydride, andreacting with stirring for 8 to 24 hours; and (3) dialyzing the solution obtained in the step (2), performing freeze drying treatment, and thus obtaining the contrast agent. The method has a simple preparation process, and experimental conditions are realized at normal temperature and under normal pressure; and the CT / MRI bimodal imaging contrast agent prepared by the method has a good CT / MRI effect, and a favorable foundation is laid for the development of a novel multifunctional contrast agent.

The invention discloses a preparation method of a gold-silver composite nanoring. The preparation method comprises the following steps: placing a silver target material in water while stirring, and irradiating the silver target material for 10-30 minutes by using laser with the wavelength of 1064nm, the power of 30-50mJ / pulse, the frequency of 5-15Hz and the pulse width of 5-15ns to obtain a silver nanoparticle colloid solution; then, irradiating the silver nanoparticle colloid solution for 2-4 minutes while stirring by using laser with the wavelength of 532nm, the power of 34-38mJ / pulse, the power of 5-15Hz and the pulse width of 5-15ns to obtain a monodisperse silver nanoparticle colloid solution; then, adding the monodisperse silver nanoparticle colloid solution to a 0.13-0.17mmol / L chloroauric acid according to a volume rate being (0.8-1.2): (0.8-1.2), and stirring for at least 30 minutes to prepare the gold-silver composite nanoring in which a silver nanoring is modified with gold nanoparticles, wherein the ring diameter of the silver nanoring is 10-25nm, the thickness of the silver nanoring is 3-6nm and the particle diameter of the gold nanoparticles is 3-5nm. The gold-silver composite nanoring prepared by the preparation method disclosed by the invention is expected to be applied to a Raman detection technology based on a near-infrared excitation SERS (Surface Enhanced Raman Scattering) effect.

The invention relates to a method for preparing a graphene biosensor, belonging to the technical field of electrochemistry. The method comprises the following steps of: immersing a processed gold electrode into graphene oxide and a sodium sulphate solution, electrically depositing the electrode through a control electric potential, taking out the electrode, washing the electrode by using water, after drying the electrode at room temperature, putting the electrode in a chloroauric acid solution, electrically depositing the electrode through the control electric potential, taking out the electrode, washing the electrode by using water, and drying the electrode at room temperature; putting a modified electrode in a conductive polymer monomer and a supporting electrolyte solution, polymerizing the electrode through the control electric potential by adopting a cyclic voltammetry, taking out the electrode, washing the electrode by using water, and drying the electrode at room temperature; and activating the modified electrode in an EDC / NHS (Dichloroethane / N-Hydroxysuccinimide) solution, and immersing the modified electrode in a vomiting toxin antibody. The method disclosed by the invention is used for fixing graphene, gold nanoparticles and conducting polymers through electro-deposition; therefore, the method is very green and environment-friendly; furthermore, the thickness of a coating and sizes and distribution densities of the gold nanoparticles can be precisely controlled, thus, the batch production repeatability of the modified electrode is good.

The invention discloses an AuNC (gold nanocluster) and CD (carbon quantum dot) composite fluorescent probe. The AuNC and CD composite fluorescent probe comprises BSA (bovine serum albumin) functionalized AuNCs (BSA-AuNCs) and fluorescent CDs in the mole ratio being 1:(1-5), wherein the BSA-AuNCs are prepared from a chloroauric acid solution, a BSA 4 solution and an NaOH solution through a reaction, and the fluorescent CDs are prepared from citric acid, diethylenetriamine and acetone through a reaction; the BSA-AuNCs and the CDs constituting the multifunctional composite fluorescent probe have specific recognition response to Hg<2+> and Cr<6+> respectively, when the BSA-AuNCs and the CDs constitute the multifunctional composite fluorescent probe, fluorescence emission of the BSA-AuNCs and fluorescence emission of the CDs are not affected mutually, respective probe detection results are undisturbed, the probe has higher sensitivity and selectivity, and respective detection of different kinds of ions and distinctive effects when two kinds of ions exist simultaneously are realized.

The invention provides a nano-gold catalyst supported on combined metal oxide, a preparation method and an application thereof. The preparation method comprises the following steps: preparing layered double hydroxides (LDH) precursor crystal nucleus and dispersing the LDH precursor crystal nucleus into sucrose solution; then adding chloroauric acid solution in the obtained mixture so as to reduce Au3+ in HAuCl4 to Au single substances by using the reduction of glucose and fructose produced by sucrose hydrolysis; in the process of reduction, crystallizing the LDHs so as to obtain solid LDH supported on nano-gold; and carrying out high-temperature roasting on the solid LDH supported on the nano-gold so as to obtain the nano-gold catalyst supported on the combined metal oxide. The combined oxide of the catalyst is taken as a carrier on which the nanosize gold particles is supported, wherein the combined oxide refers to MgO or compound of ZnO and Al2O3, and the mole ratio of the MgO to the compound of ZnO and Al2O3 is 2-6:1; the gold capacity is 0.5 to 3 percent, the size of the gold particle is 8 to 15nm, and the gold particle is ellipsoidal or polyhedral. When the catalyst is used in the catalytic hydrogenation reaction of unsaturated aldehydes, the conversion rate of reactants reaches 60 to 97 percent, and the selectivity of cinnamyl alcohol is 40 to 75 percent.

The invention provides application of a gold nanocluster as a glutathione fluorescent probe. Specifically, the gold nanocluster is prepared by the method of: reacting chloroauric acid with histidine away from light at room temperature for 2-8h. According to the invention, the gold nanocluster is adopted as a fluorescent probe and applied in glutathione detection and cancer cell recognition, and the influence of cysteine, homocysteine and other common biomolecules on glutathione detection can be effectively avoided. The method is simple, the detection range is wide and the sensitivity is high.

The invention discloses a preparation method of an electrode based on a gold nanoparticle doped covalent organic framework composite material and relates to the technical field of electrochemical sensors. The preparation method comprises the following steps: firstly, dissolving 1,3,5-tri(4-aminophenyl benzene) and 2,5-dimethoxy p-phthalaldehyde into a solvent, reacting under the catalysis of acetic acid and obtaining TAPB-DMTP-COF; secondly, dispersing the TAPB-DMTP-COF into methanol, and then adding chloroauric acid and a sodium borohydride methanol solution in sequence for reacting to obtainAu@ TAPB-DMTP-COF; dispersing the Au@TAPB-DMTP-COF in water to obtain suspension, and then modifying the suspension on the surface of a glassy carbon electrode, thus obtaining the modified glassy carbon electrode based on a covalent organic framework material. The invention constructs an electrochemical sensor for detecting chlorogenic acid; current response of chlorogenic acid is improved by modifying the glassy carbon electrode with the Au@TAPB-DMTP-COF.

The invention discloses a preparation method of silica core / mesoporous silica shell-supported gold nano-particle microspheres, and relates to a preparation method of a gold-supported nano-catalyst. The preparation method is to solve the problem of poor morphology and uniformity of the existing mesoporous silica-supported gold catalyst. The preparation method disclosed by the invention comprises the following steps: step one, preparing a silica nano-particle sol solution; step two, diluting the sol solution with de-ionized water, adding cetyltrimethylammonium bromide solution, stirring, then dripping tetraethyl orthosilicate, and then obtaining nano-particles having a core-shell structure by drying and calcination; step three, dripping a silane coupling agent, heating for reflux, and obtaining nano-particles with amino groups by centrifugation and ultrasonic washing; and step four, adding chloroauric acid, adjusting the pH value with hydrochloric acid, then dripping sodium borohydride to reduce chloroauric acid. The silica core / mesoporous silica shell-supported gold nano-particle microspheres prepared by the preparation method are uniform in particle size, the distribution of gold nano-particles is uniform, and the gold nano-particle microspheres are mainly applied to adsorption and catalysis reactions.

The invention provides a preparation method of a thorn-shaped or petal-shaped rough-surface gold-silver alloy nanometer material. The preparation method comprises the steps that gold nanoparticle seeds are prepared from a mixed solution of chloroauric acid and trisodium citrate; the gold nanoparticle seeds grow on the surfaces of gold nanoparticles through heterogeneous nucleation; and under the action of molecular synergistic adsorption of L-dopamine, stabilization of atomic clusters, reduction of gold ions and silver ions and underpotential deposition of silver atoms, the thorn-shaped or petal-shaped rough-surface gold-silver alloy nanometer material is prepared and formed. The preparation method is simple in process and effective; production cost can be lowered conveniently; the preparation method is suitable for large-scale production; and the prepared thorn-shaped or petal-shaped rough-surface gold-silver alloy nanometer material is of a unique bionic structure, large in specific surface area and capable of loading a great amount of active medicine and molecular dye. Therefore, the preparation method has wide application prospect in the fields such as SERS sensing, catalysis, diagnosis and treatment and adsorbing materials.

The invention discloses a preparation method and application of carbon dot / gold composite nanoparticles. Citric acid and cysteine are taken as raw materials, and N-S codoping carbon dots are synthesized; the carbon dots serve as the heterogeneous nucleation center of the gold nanoparticles, a reducing agent and a stabilizing agent, any other auxiliaries such as a surface active agent or an adsorbent do not need to be added, and the carbon dot / gold composite nanoparticles are prepared by further reducing chloroauric acid. The preparation method of the carbon dot / gold composite nanoparticles is simple, convenient, feasible, mild in reaction condition and environmentally friendly, and the prepared carbon dot / gold composite nanoparticles have the characteristics of being high in quantum yield, small in size, low in biotoxicity, resistant to photobleaching and the like, and can be applied to the fields such as cell imaging or catalytic reaction research.

The invention discloses a surface enhanced Raman scattering tag based on a gold and silver nanowire array and a preparation method thereof. The tag is formed by a gold and silver double-metal nanowire array, each nanowire in the array is formed by two layers of core-shell metal, wherein the core layer is a silver nanowire, the shell layer is a gold nanowire, and organic molecules adsorbed by the outer surface of the shell layer are Raman report molecules. The method comprises the following steps that a uniform pure silver nanowire array is formed; a porous alumina film is soaked in deionized water for ultrasound, then the deionized water is replaced, and the step is repeated for three times; the porous alumina film is soaked in a sodium hydroxide solution with the concentration of 3 M for three minutes, then the porous alumina film is repeatedly washed with the deionized water for three times after being taken out, and then the porous alumina film is blow-dried with nitrogen; then a pure silver nanowire substrate is soaked in a chloroauric acid aqueous solution with the concentration of 1 mM to 5 mM; and after the pure silver nanowire substrate is taken out, the pure silver nanowire substrate is thoroughly washed with the deionized water, and then the pure silver nanowire substrate is blow-dried with the nitrogen. The surface enhanced Raman scattering tag has the advantages of good uniformity and superhigh repeatability, and the preparation method has the advantages of simplicity and low cost.

The invention provides a composite gold nanorod carrier having photo-thermal / photodynamic therapy treatment performance and a preparation method thereof. The composite gold nanorod carrier uses a gold nanorod as a core and uses silicon dioxide as a shell layer, a near infrared fluorescent dye for photodynamic therapy is modified on the outer surface of the shell layer. The preparation method comprises the steps that a chloroauric acid solution and a cetyl trimethyl ammonium bromide solution are mixed, a sodium borohydride ice water mixed solution is added to obtain a nano gold seed solution A; a silver nitrate solution and a chloroauric acid solution are added to a binary surface active agent solution, a hydrochloric acid is added after reaction to obtain a solution B, then ascorbic acid and the solution A are added, and a gold nanorod is obtained after reaction; a tetraethoxysilane methanol solution and an aminopropyl trimethoxy silane methanol solution are added to a gold nanorod solution to obtain composite nanoparticles; 1-(3-dimethyl amino propyl)-3-ethyl carbodiimide hydrochloride is added to the near infrared fluorescent dye, then N-hydroxyl succinimide is added to obtain a solution C; the composite nanoparticle solution is mixed with the solution C to obtain a product.

The invention provides a fluorescence probe, the synthetic method and the use which is to test the cell hydroxyl free radical. The process is: a. heat and chloroauric acid of 150.0 weight concentration and back flow, with mixing, the sodium citrate of 5.0-7.0 is added into the solution to back flow for 10-20min, then to cool in room temperature to get the golden nanometer particle solution; b. mix the particle with the DNA single chain with 5'end modified fluorescein and 3'end modified sulfydryl according to 1:200-500, then to set in room temperature for 1224h, last to adjust the pH by the phosphoric buffer; next to mix the mixture with the 0.5-5mol / L NaCl according to 1:0.1-0.3(V / V) which is set in room temperature for 35-45h; last to centrifugate to remove the upper solution and the deposition is solved in the 0.1-0.3mol / L phosphoric buffer which is the fluorescence probe solution.

The invention discloses a preparation method of precious metal loaded Bi2WO6 visible light photocatalyst, which is mainly characterized in that the photo-induced electrons and positive holes of the Bi2WO6 photocatalyst are easy to be re-combined to reduce the photocatalytic activity thereof, and a precious metal is loaded on the surface of the Bi2WO6 photocatalyst to greatly improve the separation of the photo-induced electrons and the positive holes so as to improve the photocatalytic performance of the Bi2WO6 visible light photocatalyst. The preparation method comprises the following steps of: (1) synthesizing Bi2WO6 by a liquid phase method: firstly dissolving bismuth salt in certain amount of acetic acid, blending the solution with tungsten salt according to a metering ratio, uniformly stirring, filling the mixture in a reaction kettle to react at 120-240 DEG C for 10-20 h, centrifugally separating the obtained products and drying the same at 50-100 DEG C in vacuum; (2) the Bi2WO6 synthesized by the liquid phase method is of a flower-shaped grade structure assembled by nanometer pieces, dispersing the obtained Bi2WO6 with flower-shaped structure in a mixed solvent of methanol and water, adding different dosages of such acids or salts containing precious metals as chloroplatinic acid or chloroauric acid, uniformly stirring, and ultrasonic dispersing for 10-120 min; (3) putting the mixed solution under an ultraviolet lamp, and irradiating for 10-240 min to obtain the precious metal loaded Bi2WO6 visible light photocatalyst. The method has the advantages of simple technique and low cost, and the prepared precious metal loaded Bi2WO6 visible light photocatalyst has high visible light catalytic activity.

The invention relates to a method for displaying latent fingerprints on a fluorogold nano-cluster protected by protein, and belongs to the technical field of fingerprint identification. According to the method, bovine serum albumin is used as a reducing agent and a protective agent, a gold nano-cluster is compounded through an immersion method, and latent fingerprints on a PVDF film and an adhesive tape base are marked and displayed utilizing the near-infrared fluorescence emitting performance of the nano material. The method specifically comprises the steps that the bovine serum albumin, chloroauric acid and sodium hydroxide are used as reaction raw materials to prepare gold nano-cluster solutions; fresh fingerprint detection materials are soaked, washed and irradiated by an ultraviolet lamp, and a fluorescence imaging system is used for photographing fingerprint displaying images. According to the method, the gold nano-cluster has strong fluorescence and stability, and has strong combination ability with fingerprint residue. The method is quick in operation, reagents are safe and friendly to the environment, display efficiency, accuracy, flexibility and repeatability are ideal, and therefore the method has good application prospects in the field of fingerprint identification.

The invention relates to a preparation method of a CT / MR bimodal imaging nano contrast medium with a folate targeting function. The method comprises the following steps of: (1) preparing FA-PEG-COOH; (2) modifying the dendrimer by use of DOTA-NHS, COOH-PEG-FA and mPEG-COOH to obtain the pegylation dendrimer modified by DOTA and folate; and (3) adding chloroauric acid solution, NaBH4 solution and Gd(NO3)3.6H2O into the dendrimer solution obtained in the step (2), then adding triethylamine and acetic anhydride, and after reaction, performing dialysis and freeze-drying. The preparation method provided by the invention is simple and easy to operate, and has mild reaction conditions and prospects for industrial implementation; and the CT / MR bimodal imaging nano contrast medium has better water solubility and stability, realizes a specific targeting function for the folate receptor high-expression cancer cell, and is expected to be applied to early detection of tumor.

The present invention provides are a gold nanoflower structure and a preparation method therefor. The gold nanoflower structure is a gold nanoflower particle, with round-head columns being uniformly distributed at the periphery thereof, obtained by using gold octahedrons, gold balls or gold tetrahedrons as seed crystals and reducing chloroauric acid by using weak reductant in an environment of high-concentration polyvinylpyrrolidone. In addition, also provided in the present invention are a gold nanoflower / quantum dot composite probe for living cell immunofluorescent labeling and photothermal therapy, a preparation method therefor and a use thereof. In comparison with traditional probes, the probe, incorporates the features of photothermal therapy and fluorescent labeling, and is capable of killing cancer cells in an effective and directional way. Two light sources are adopted to bring a tremendous photothermal conversion efficiency and a greater enhancement on fluorescence intensity of quantum dots respectively, thus mutual interference of two effects are avoided tactfully. The coating of silicon dioxide averts the biotoxicity of the gold nanoflower and the quantum dot effectually, enabling the surface of the composite probe to be easily functionalized and also imparting an extraordinarily excellent biocompatibility to the composite probe.

The invention discloses a method for preparing flower-like nanometer gold, relating to nanometer gold. The invention provides a method for preparing the flower-like nanometer gold covered by trypsinase with higher stability, better biocompatibility and more uniform particles. The flower-like nanometer gold consists of nanometer particles and is covered by the trypsinase, and the particle diameter of the product is between 100 and 200nm with uniform shapes and particle diameters. Chloroauric acid is mixed with trypsinase solution to obtain a mixed liquid of the chloroauric acid and the trypsinase solution; ascorbic acid is added into the mixed liquid of the chloroauric acid and the trypsinase solution to obtain reaction solution; and the reaction product is collected and washed to obtain the product of the flower-like nanometer gold.