Gold nanoparticles prepared by aqueous synthesis and its fluorescence properties

Au nanoparticles encapsulated by PAMAM dendrimers were prepared using PAMAM dendrimers as template and ethanol as reducing agent in water medium, respectively, which have good water-solubility and well-stability in water phase for more than 1 year. Au nanoparticles with controlled size in a range of 1-4 nm were obtained by changing the molar ratio of Au³⁺ to PAMAM dendrimers. The results show that there was a strong resonance Rayleigh scattering peak at 385 nm and a fluorescence peak at 402 nm. The photolumine-scence quantum yield of the prepared Au nanoparticles was more than 10% at room temperature, which is about 2 orders of magnitude higher than that of Au nanoparticles prepared by other methods, so it have potential application prospect in fingerprint recognition, photocatalysis and so on.