6 results about "Gold nanocrystal" patented technology

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

The invention relates to the field of materials, and discloses a surface wave-shaped gold nanocrystalline material and a preparation method and application thereof.The preparation method comprises the steps that a chloroauric acid solution A1, a sodium hydroxide solution B1 and a solution C1 containing a first ligand react to obtain a first solution; the first ligand is selected from more than one of nitrite, citrate, sulfite and hypophosphite; a solution 1 containing a second ligand, a solution 2 containing a nanocrystalline template and a reducing agent solution 3 are mixed to obtain a mixed solution 4, the solution I is added into the mixed solution 4 to obtain a solution II, and the second ligand is selected from one or more of polyvinylpyrrolidone and poly (diallyldimethylammonium chloride) heat exchange sodium dodecyl benzene sulfonate; and mediating a mediating agent into the solution II to obtain the gold nanocrystalline material with the wavy surface. According to the method, the gold nanocrystals are synthesized in a water phase at normal temperature and normal pressure by adopting a wet chemical method, the surfaces of the prepared gold nanocrystals are wavy, and the roughness is continuously adjustable.

The invention provides a preparation method of a symmetric broken gold nanocrystal with a controllable length-diameter ratio based on microwave-assisted ultrafast synthesis. According to the method, under the synergistic effect of a surfactant and a pre-synthesized gold seed, reaction conditions are accurately controlled through key parameters such as microwave radiation temperature, power and reaction time of a microwave reactor, and after the reaction is completed, the gold nanocrystal with good monodispersity and adjustable length-diameter ratio can be obtained through centrifugal purification. Compared with a traditional wet chemical synthesis process, the method has the advantages that the reaction time is greatly shortened to be within 1 hour; by utilizing the characteristics of instantaneity and uniformity of microwave heating, the high uniformity of the nanocrystal size is realized; by regulating and controlling the type and the concentration of the surface active agent, the regulation and control of the symmetrical broken morphology of the gold nanocrystal can be realized; the length-diameter ratio of the gold nanocrystals can be directly controlled by accurately regulating and controlling the microwave temperature, the method is easy to operate and good in repeatability, and a novel efficient and controllable preparation way is provided for application of functional precious metal nanomaterials.

The application discloses an electrochemical aptamer sensor for high-sensitivity detection of alpha-amatoxin and a preparation method and application thereof, and belongs to the technical field of electrochemical detection. The working electrode of the sensor is a glassy carbon electrode, gold nanocrystals are used to modify the electrode first, then aptamers are connected to the gold nanocrystals through gold-sulfur bonds, and the remaining active sites are closed by using mercaptohexanol. The electrochemical aptamer sensor has high selectivity and sensitivity for alpha-amatoxin, and has the advantages of simple sample pretreatment steps, rapidness and convenience. The detection result of an actual human sample is satisfactory. The electrochemical aptamer sensor prepared by the application has been successfully applied to the detection of alpha-amatoxin in human urine, and has the advantages of extremely low detection limit, wide detection range, excellent selectivity and stability.

An acetone gas sensor based on PtRu alloy-modified hollow spherical ZnFe2O4, its preparation method, and its application are disclosed, belonging to the field of semiconductor oxide gas sensor technology. The sensor comprises an Al2O3 ceramic tube substrate with two parallel, ring-shaped, and discrete gold electrodes on its outer surface; a nano-sensitive material coated on the outer surface of the Al2O3 ceramic tube and the gold electrodes; and a nickel-chromium alloy heating coil placed inside the Al2O3 ceramic tube. The nano-sensitive material is a bimetallic PtRu alloy-modified hollow spherical ZnFe2O4. The ZnFe2O4 has a hollow microsphere structure, and its large specific surface area provides more reaction sites. The addition of PtRu alloy nanocrystals enhances the reaction due to sensitization and the synergistic effect of the two materials. Even with a relatively small bimetallic loading, better gas-sensing performance can be obtained, resulting in a gas-sensing element with good gas-sensing response, high selectivity, and fast response recovery speed for acetone.