1118 results about "Chloroauric acid" patented technology

The invention discloses an application of nano-gold directly bonded with luminol in an immunoassay. The invention is characterized in that the immunoassay probe of a nano-gold directly bonded with luminol comprises antibodies which are labeled by the nano-golds directly bonded with luminol, wherein the nano-gold directly bonded with luminol are prepared through reducing chloroauric acid by the luminol at a single step; a chemiluminescence immunoassay method is based on the immunoassay probe of the nano-gold directly bonded with luminol; and a kit is used for carrying out the immunoassay method. The chemiluminescence immunoassay method of the invention has the advantages of high sensitivity (for instance, the detection limit can reach 1.0pg / mL for detecting human IgG), wide range of linearity, good repeatability, simple operation, low cost and the like, can be applied to detect multi-analyte in various samples and has key application prospect in fields, such as clinical diagnosis and cure, drug analysis, food security detection, environmental monitoring and the like.

The invention discloses a method for preparing gold nano-rods. The method includes the steps: adding chloroauric acid solution and optional gold seed generating regulating agents into CTAB (cetyl trimethyl ammonium bromide) solution, adding silver nitrate solution, weak reducing agents and strong reducing agents into the CTAB solution and reacting at the constant temperature of 25-40 DEG C for 5-30min to obtain reaction liquid A; and adding silver nitrate solution, optional gold nano-rod growth regulating agent solution and water into the reaction liquid A to obtain reaction liquid B, and continuing reaction to obtain the gold nano-rods. The method is simple in process and operation and fine in reproducibility, the diameter of coverage of the prepared gold nano-rods is as small as 5nm to tens of nanometers, LSPR (localized surface plasmon resonance) peak value coverage in the length direction ranges from 630nm to 1010nm, counts in a TEM (transmission electron microscopy) graph indicate that more than 90% of rod products among obtained gold nano-particle products are high in rod yield, and the ratio of an LSPR peak value to a TSPR (transverse surface plasmon resonance) peak value is not lower than 2 in a UV-Vis (ultraviolet visible) absorption spectrogram. Raw materials used in the method are widely and easily obtained, and production cost is low.

The invention discloses a method for preparing a noble metal modified one-dimensional titanium dioxide Hg-removing catalyst. The method comprises the following steps of: by taking a titanium dioxide nanotube as an active main body and a noble metal salt or a nonmetal modifier as a modifier, heating in water, roasting, optically reducing, drying and grinding to prepare the noble metal elementary substance modified titanium dioxide nanotube photocatalyst. The nano titanium dioxide is in a rutile type, an anatase type or a mixed type of rutile and anatase; the noble metal salt is one or mixture of a plurality of silver nitrate, palladium chloride, palladium nitrate, chloroplatinic acid or chloroauric acid; and a photo-reduction sacrifice agent is one or mixture of a plurality of methanol, ethanol, ethylene glycol, propanol, isopropanol or propylene glycol. The invention is simple in process, easy to master and not easy to inactivate; and the prepared titanium dioxide nanotube and the noble metal elementary substance modified titanium dioxide nanotube photocatalyst can efficiently catalyze and oxidize Hg elementary substances in flue gas.

The invention discloses application of glutathione-based stable gold nano cluster particles to detection of a sulfhydryl compound, wherein the glutathione-based stable gold nano cluster particles are prepared from a chloroauric acid solution and a glutathione solution, wherein a molar ratio of chloroauric acid to glutathione is between 1:0.5 and 1:1. By using an fluorescence enhancement characteristic of the glutathione-based stable gold nano cluster particles after the addition of the sulfhydryl compound, through detecting the change of fluorescence intensity before and after the sulfhydryl compound with an unknown concentration reacts with the glutathione-based stable gold nano cluster particles, a linear standard curve chart is drawn, and a calibration relation is obtained by adopting linear fitting, so that the sulfhydryl compound with the unknown concentration is detected.

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 gold nanoflower preparing method and the application of gold nanoflowers. The preparing method comprises the following steps that 1) under room temperature, polyphenol is added to water solution with the pH value of 7-12 to obtain mixed solution; 2) chloroauric acid and hydrogen peroxide are then added in sequence, shaking up is carried out to obtain reaction solution; 3) the reaction solution is centrifuged, supernatant is abandoned, and the gold nanoflowers are obtained after washing. The particle diameters of the gold nanoflowers obtained under different pH values are 50-200nm, stability is good, the gold nanoflowers can be used in a biological body as a medicine carrier and have good biocompatibility, the gold nanoflowers can be used in chemiluminescence analysis, the signal intensity of a luminal chemiluminescence system can be obviously enhanced, the gold nanoflowers can be used in surface-enhanced Raman scattering (SERS) analysis, and the sensitivity is better than that of spherical gold nanoparticles. The gold nanoflower preparing method has the advantages that raw materials are easy to get, reaction conditions are mild, efficiency is high, speed is high, and batch preparing and producing are benefited.

The invention discloses a method for rapidly preparing a gold nanorod, which belongs to the technical field of a nano material, and solves the problem that the existing gold nanorod seed induction growth method is long in consumed time. The method is characterized in that cationic surface active agent chloride quaternary ammonium salt is used as a protective agent, gold seeds which are obtained by reducing sodium borohydride through the reducing agent sodium oleate, ascorbic acid are added into a chloroauric acid solution under the assistant effect of ions and silver ions to obtain gold nanorods. According to the method, the synthesis of the gold nanorods can be completed in 15 minutes, so that not only can the synthesis time of the gold nanorods be greatly shortened and a material base be provided for the real application of the gold nanorods, but also the yield of the gold nanorods is high, and fewer spherical particles exist.

The invention discloses a sea urchin-shaped hollow gold and silver alloy nano particle and a preparation method and application thereof. The method comprises the following steps: dissolving silver nitrate into water; heating the mixture of the silver nitrate and the water till boiling; adding trisodium citrate aqueous solution in the mixture and keeping boiling for 3-30 minutes to obtain a silver colloid; mixing chloroauric acid aqueous solution and the water; adding the silver colloid under the condition of agitation at the temperature of 15 DEG C; adding hemoporphyrin metalporphyrin aqueous solution and obtaining a reaction solution after 5 min reaction; performing centrifugalization of the reaction solution, washing deposit obtained via centrifugalization, and obtaining the sea urchin-shaped hollow gold and silver alloy nano particle. The diameter of the nano particle is 80 nm-300 nm, the hollow size is 20 nm-50 nm, the length of a stab is 10 nm-30 nm, the diameter of the stab is 10 nm. The preparation method is simple, low in cost, gentle in condition, short in time, easy in process control, and large in production capacity. The obtained nano particle can be well applied to organic molecule detection, earlier detection of tumour and photothermal treatment.

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 relates to a preparation method of fluorescence gold nano clusters with stable chicken ovalbumin. The method includes: dissolving commercially available chicken ovalbumin in deionized water to prepare solution 0.5-10mg / mL in concentration; mixing the solution with chloroauric acid aqueous solution to obtain mixed solution, with certain mole ratio, of the chicken ovalbumin and the chloroauric acid aqueous solution; adjusting pH of the mixed solution to 11.5-13, allowing for microwave reaction for 15-20s, and naturally cooling to room temperature to obtain fluorescence gold nano clusters emitting red light. The fluorescence gold nano clusters prepared by the method is applicable to the bio-metical field and the sensor field.

The invention discloses a method for preparing gold nanorods and belongs to the field of nano material preparing. The method includes the following steps that firstly, a mixed solution of quaternary ammonium bromide, oleate, chloroauric acid hydrated, silver nitrate, an acid solution and ascorbic acid is prepared, and a growth solution is obtained; secondly, in a cetyl trimethyl ammonium bromide surface modifying solution, strong reductant sodium borohydride is used for restoring the chloroauric acid hydrated to obtain a gold seed solution; thirdly, the gold seed solution is injected into the growth solution for reaction for 3-15 hours, and the gold nanorods are obtained. The method for preparing the gold nanorods has the advantages that the requirement for equipment is low, the method is easy to operate, conditions are gentle, reproducibility is high, and large-batch preparing can be conducted; the obtained gold nanorods are high in yield which can reach 99 percent or higher, consistency is high, the variable coefficient of length and the variable coefficient of width are within 10 percent, the length-diameter ratio can be regulated in the large range of 1.5-8, and a solid foundation is laid for practical use of the gold nanorods.

The invention discloses a metal carrier load gold catalyst and application thereof in preparing aldehyde or ketone by selectively oxidizing catalytic alcohol, wherein the catalyst is prepared by isopyknically impregnating a metal fiber or metal particle carriers with chloroauric acid or sodium chloraurate solution and baking for 2 hours at a temperature between 250 DEG C and 400 DEG C, and containing 0.5-6.0 percent of gold and 94.0-99.5 percent of carrier; in the process of preparing the aldehyde or the ketone by vapor phase selective oxydehydrogenation of the catalytic alcohol, the catalystadopts a fixed bed reaction device, takes oxygen or air as an oxidant and selectively oxidizes the alcohol to generate aldehyde or ketone under the conditions that the reaction temperature is 250-350DEG C, the weight hourly space velocity of the alcohol is 10-60<-1> hours and the mole ratio of O2 to hydroxyl group is 0.4-1.2. The catalyst has favorable heat conductivity, high low-temperature activity, good stability, low cost, high efficiency for the catalytic alcohol to prepare the aldehyde or the ketone by selective oxydehydrogenation, and environment friendliness.

The invention discloses a luminol direct bonded nano gold nucleic acid analyzing probe and a novel chemiluminescence analysis method. The invention provides the luminol direct bonded nano gold nucleic acid analyzing probe, a chemiluminescence analysis method based on the luminol direct bonded nano gold nucleic acid analyzing probe and a kit for constructing the analyzing method; the analyzing probe comprises nucleic acid which is directly bonded by luminol and marked by nano gold; and luminol direct bonded nano gold is obtained by reducing chloroauric acid at one step by luminol. The chemiluminescence analysis method based on the nucleic acid analyzing probe of the invention has the advantages of high sensitivity (for example, specific sequence single-chain DNA detection limit can reach 1.9*10<-16>mol / L), wide linear range, high repeatability, simple operation, low cost, and the like, can be used for the detection of DNA, RNA and adapter corresponding ligands in various samples and has wide application prospect in the fields of clinical diagnosis and treatment, pharmaceutical analysis, food safety detection, environmental monitoring, and the like.

The invention relates to a method for preparing Au / g-C3N4 composite-type micro-nano material. The method is realized by steps of adding g-C3N4 powder in 400-900nano in granularity to chloroauric acid solution, ultrasonically dispersing the g-C3N4 powder so as to prepare turbid liquid; heating the turbid liquid in water bath; then, adding sodium citrate to solution, stirring, washing, separating and drying a mixture so as to obtain Au / g-C3N4 composite-type micro-nano material; the Au / g-C3N4 composite-type micro-nano material has excellent photochemical catalysis effect to formic acid oxidation; and oxidation potential is negatively shifted by 800mV (close to the catalytic oxidation potential of Pt) without ctalyst poisoning phenomenon. According to the advantages of the invention, acquired composite material particles are even and not united; a preparation method is simple; and cost is relatively low.

The invention provides a porous solid material supported ionic liquid-gold catalyst, as well as preparation and application thereof. The catalyst comprises a porous solid material carrier and a complex which is prepared from an ionic liquid and a metal ionic compound and is loaded on the carrier surface, wherein the metal ionic compound is a gold compound or a combination of a gold compound and a third metal chloride; the gold compound is selected from one of gold chloride, chloroauric acid, ethylenediamine gold chloride, chloro(triphenylphosphite)gold and chloro(triethylphosphine)gold; the third metal is selected from one of Cu, In, Bi, Ba, Sr, Fe, Mn, Zn, Co, Cs, K, Ca, Sn and Ni; and the ionic liquid is an imidazole ionic liquid. The porous solid material supported ionic liquid-gold catalyst has good chemical and thermal stability and high heat transmission efficiency in the reacting atmosphere for synthesizing vinyl chloride by ethyne hydrochlorination, and has the characteristics of high catalytic activity, high selectivity, good stability, low cost and the like.

The present invention is a preparation method of gold nanorods whose length-to-diameter ratio can be adjusted in a large range. The strong reducing agent sodium borohydride reduces tetrachloroauric acid to obtain gold seed solution; the preparation of growth solution: prepare the mixed solution of hexadecyltrimethylammonium bromide, tetrachloroauric acid and silver nitrate, and the mol ratio of the three is 20:1:0.1~20:1:5, add crotonic acid solution to obtain a growth solution; growth of gold nanorods: inject gold seed solution into the growth solution, react for 6-12 hours, and obtain gold nanorods. The invention adopts crotonic acid as growth solution modifier, and solves the biological toxicity and biological modification problems caused by CTAB. The yield of the short-length-diameter ratio gold nanorods prepared can be as high as about 90%, the size distribution is narrow, and the length-diameter ratio is about 1.92. The aspect ratio of the prepared gold nanorods can be adjusted in a wide range from 1.9 to 7.5.

The invention discloses a gold nanocluster-gold nanoparticle-titanium dioxide compound photocatalyst and application thereof. The gold nanocluster-gold nanoparticle-titanium dioxide compound photocatalyst having different particle sizes is firstly obtained by preparing a gold nanocluster solution based on chloroauric acid and a reducing type glutathione as raw materials and carrying out an impregnation method and illumination condition control on gold nanocluster solution and titanium dioxide nanoparticles. The gold nanocluster-gold nanoparticle-titanium dioxide compound photocatalyst is simple in preparation method without high temperature and high pressure conditions; compared with the existing gold nanocluster-titanium dioxide and gold nanoparticle-titanium dioxide catalysts, the gold nanocluster-gold nanoparticle-titanium dioxide compound photocatalyst disclosed by the invention is higher in photocatalytic efficiency and hydrogen production efficiency, can be used for hydrogen production by photolysis of water, and is beneficial to sustainable development of environments and energy sources.

The invention discloses full-bloom flower-shaped gold nanoparticle and a preparation method thereof. The preparation method comprises the following steps of: by adopting hexadecyl trimethyl ammonium chloride (CTAC) as a surfactant, reducing chloroauric acid (HAuCl4) by utilizing ascorbic acid (AA); and preparing the full-bloom shaped flower-form gold nanoparticle by one step without seeds by controlling the concentration of the hexadecyl trimethyl ammonium chloride (CTAC). Characterization results of a scanning electron microscope show that the prepared gold nanoparticle is shaped like a full-bloom flower; moreover, the product is uniform and the mono-dispersion is good; the ultraviolet-visible absorption spectrum shows that the surface plasmon resonance peak of the flower-form gold nanoparticle is in a near-infrared area; technical characterization results of surface enhanced raman scattering prove that the flower-form nanoparticle has better surface-enhanced performances.

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 provides a preparation method of a hollow gold nanometer cage, comprising the following steps: dissolving chloroauric acid, hexamine, and a protecting agent in water to prepare a growing liquid; getting the growing liquid and adding in a reducing agent and gold nanometer particle and mixing well to prepare gold seed solution; getting the growing liquid, adding in silver salt and the reducing agent, mixing well to prepare a mixed solution; adding the gold seed solution in the mixed solution, standing and reacting to prepare the hollow gold nanometer cage. The method provided by the invention directly enables the gold nanometer particle to grow into the hollow gold nanometer cage in water phase at normal temperature; besides, the process is simple, the reaction is easy to control, and the efficiency is high. Simultaneously, the preparation method has no need of performing post treatment to the product, thereby reducing the use amount of the reagent, reducing the production cost and simplifying the operation steps.

A catalyst with high reaction activity, selectivity and stability for preparing halophenylamine by catalytic hydrogenation of halonitrobenzene is composed of carrier (ZrO2, TiO2, SiO3, or MgO) and active component (Au) (0.5-10 Wt %). Its preparing process includes such steps as providing chloroauric acid as precursor, depositing with urea, and ageing, washing, drying, and calcining at 200-350 deg.C.

The present invention relates to an electrochemical biosensor for detecting hydrogen peroxide, a preparation method and an application thereof. The preparation method comprises the steps of (1) synthesizing the silica-three-dimensional graphene composite material; (2) doping nitrogen and carbon into the synthesized silica-three-dimensional graphene composite material; (3) pretreating a glassy carbon electrode; (4) preparing the glassy carbon electrode modified by the nitrogen-carbon-doped silica-three-dimensional graphene composite material through the dispensing method; (5) putting the glassy carbon electrode into a chloroauric acid solution to prepare gold nanoparticle-nitrogen-carbon-doped silica-three-dimensional graphene glassy carbon electrode through chronoamperometry; (6) dipping the glassy carbon electrode into a double-sulfhydryl-modified GDNA solution and cultivating for 2-4 hours; (7) dipping the composite electrode into a hemin solution for 10-14 hours. The electrochemical biosensor is good in stability and reproducibility, high in specificity and sensitivity, fast and simple and convenient to operate. The electrochemical biosensor can be used for detecting the content of hydrogen peroxide in biological samples, cosmetics and the like.

The invention discloses a method for preparing three-layer core-shell structural gold magnetic nano particles. The method comprises the following steps of: preparing amino modified core-shell structural Fe3O4 coated SiO2 particles; reducing chloroauric acid by using tetra-hydroxymethyl phosphorus chloride (THPC), wherein the obtained particles carry negative charge and are easily adsorbed to the surfaces of the amino modified Fe3O4 coated SiO2 particles; mixing and stirring suspension of the amino modified Fe3O4 coated SiO2 particles and nano gold suspension, and thus obtaining assembled gold magnetic composite particles Fe3O4 coated SiO2 / Au; and performing multi-step reduction on the surfaces of the THPC reduced nano gold particles which are adsorbed to the surfaces of the Fe3O4 coated SiO2 particles and used as crystal nuclei by using formaldehyde to obtain complete gold shells, and thus obtaining the three-layer core-shell structural gold magnetic nano particles Fe3O4 coated SiO2 coated Au. The prepared particles are uniform in particle diameter distribution and high in dispersibility, stability, magnetic responsibility and biocompatibility.

The invention relates to the field of nano material development and application, and discloses a method for synthesizing multi-branch colloidal gold nano particles different in grain diameter and high in light absorbing intensity through colloidal gold seed mediation growth. The method comprises the steps that firstly, a conventional trisodium citrate reduction method is adopted, Au3+ in chloroauric acid molecules is reduced into Au0, and ball-shaped colloidal gold seeds are obtained; then, the colloidal gold seeds are added into a growth solution, wherein the growth solution mainly comprises ultrapure water, chloroauric acid, trisodium citrate and other solutions; a magnetic stirring device is used for performing slow stirring, after the solution is evenly mixed, the solution is heated to 50 DEG C, and the rotating speed is increased at the time; and meanwhile a sufficient hydroquinone solution is added at a time, the temperature of the mixed solution is maintained at 50 DEG C, heating is stopped after the reaction is continuously carried out for 10 min, and a multi-branch colloidal gold solution high in light absorbing intensity can be obtained through cooling to the room temperature. The method has the beneficial effects of being easy to operate, simple in procedure, rapid in reaction, good in controllability, high in repeatability and the like.

The invention provides a preparation method and an application of a graphene oxide-gold nano-rod composite nano-material. The method comprises the following steps: 1, sequentially adding silver ions, ascorbic acid (VC) and an auric chloride acid solution to synthesize gold nano-rods with colloidal gold nanoparticles as nucleation sites; 2, selecting a monolayer graphene oxide solution, further processing by using NaOH and sodium monochloroacetate, neutralizing an alkali residual after a reaction by using diluted hydrochloric acid, and modifying by an active carboxyl group to prepare sulfhydrylated graphene oxide (GO-SH); and 3, taking the gold nano-rods (GNRs) prepared in step 1 and the GO-SH prepared in step 2, stirring for full mixing, standing, centrifuging, and dispersing the obtained material in deionized water. The method has the advantages of simplicity, strong operationality and good reappearance, and the prepared nano-material has very good mono-dispersion and stability in an aqueous solution, and provides powerful safeguard for application in biological detection, sensing and chemical analysis.

The invention discloses a preparation method of Au@Cu2-xSe cage-like core-shell nanostructures. The preparation method comprises: 1, using sodium citrate to reduce chloroauric acid to obtain spherical gold nanoparticles; 2, by using the spherical gold nanoparticles as a template, using ascorbic acid to reduce a copper salt to obtain gold / cuprous oxide nano core-shell structures; 3, using potassium borohydride to reduce selenium powder in a strong base environment to obtain a selenium source, and mixing and reacting the obtained selenium source with the gold / cuprous oxide core-shell nanoparticles; and 4, carrying out centrifugal washing treatment, and vacuum drying treatment, and finally obtaining the gold / cuprous oxide cage-like core-shell nanostructures. The method is easy in operation, good in repeatability, and high in yield, and the prepared product is good in stability.

The invention discloses a method for preparing gold nanoparticles. Under the anaerobic condition and at the room temperature, micro-nano hydrogen bubbles are used as reducing agent to reduce chloroauric acid, gold seeds are added, and a seed growth method is adopted to conduct reaction and preparation to obtain the gold nanoparticles. The preparation condition is moderate, the reaction is easy to amplify, new impurities are not led in the gold nanoparticles, the diameters of the gold nanoparticles are small, and uniformity is good.

Disclosed are a preparation method of low-fluorescent-background assembled gold magnetic composite nanometer particles and application thereof. The preparation method includes steps of preparing magnetic nanometer Fe3O4; preparing Fe3O4@SiO2 particles, decorating the surfaces of the Fe3O4@SiO2 particles with amino perssad; preparing small-diameter nanometer particles by utilizing sodium borohydride to reduce chloroauric acid; mixing the F33O4@SiO2 particle injectable suspension and the nanometer injectable suspension according to the volume proportion of 1:3, stirring the same ultrasonically, and obtaining assembled Fe3O4@SiO2@Au gold magnetic composite nanometer particles by coordinate bond of nanometer gold particles and the amino perssad on the surface of the Fe3O4@SiO2 particles. The Fe3O4@SiO2@Au gold magnetic composite nanometer particles are prepared by self-assembled technology, and are controllable in size, uniform in distribution, excellent in dispersion, stability and biocompatibility and lower in preparation cost. The preparation process is simple, requires mild reaction conditions, and has the advantages of low cost and convenience in operation.

The invention relates to a method for applying a gold hydroxyapatite loaded catalyst to catalytic oxidation reaction of formaldehyde at room temperature, belonging to the technical field of indoor air purification. The method is characterized by comprising the following steps: by taking calcium nitrate and diammonium hydrogen phosphate as precursors, obtaining hydroxyapatite by a liquid deposition method; by taking chloroauric acid as a precursor and the hydroxyapatite as a carrier, preparing the gold hydroxyapatite loaded catalyst by an urea homogeneous precipitation method, wherein the percentage by weight of Au is 0.1%-10%; and carrying out the reaction of removing formaldehyde by catalytic oxidation in a reactor, and passing formaldehyde gas through a gold hydroxyapatite loaded catalyst bed layer, wherein the reaction temperature is ranged from -15 DEG C to 25 DEG C. The method provided by the invention has the beneficial effects that formaldehyde pollutants are oxidized to CO2 and H2O at room temperature without complex operations such as temperature rising and heating. The method satisfies the actual using demands on indoor air purification, and has a wide application prospect in the field of indoor air pollutant purification.

The invention discloses a small-size gold nanorod and a preparation method and applications thereof. The growth reaction is adjusted by utilization of cationic-anionic surfactants as a mixed growth template, and synthesis of the small-size gold nanorod with the diameter of 5-9 nm is achieved through the non-gold-seed one-step method. The diameter and the length-diameter ratio of the small-size gold nanorod are adjusted through changes of the mole ratio of the chloroauric acid to the cationic-anionic surfactants to the silver nitrate. Operation is simple, consumed time is short, repeatability is good, and the small-size gold nanorod good in monodispersity and uniform in size can be obtained with no ultrasound in the preparation process. The diameter of the small-size gold nanorod is 5-9 nm, the size is small, and the ratio of the absorption value of a longitudinal surface plasma resonance absorption peak to the absorption value of a transverse surface plasma resonance absorption peak of the small-size gold nanorod is 2.5-5.5. The prepared small-size gold nanorod can be applied to the fields of preparation of photo-thermal treatment drugs, optical mark drugs, sensors and the like.