Abstract: 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 photoluminescence 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.

Key words: PAMAM dendrimer, Au nanoparticles, Resonance Rayleigh scattering, Photoluminescence quantum yield