Facile Synthesis of Intelligent Polymers Modified Gold Nanoparticles in Aqueous Solution

This paper describes the synthesis of gold nanoparticles (GNPs) stabilized with intelligent poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA). First, the dithioester-terminated PDMAEMA was prepared by the reversible addition-fragmentation chain transfer technique. Then, the dithioester-terminated PDMAEMA was reduced to a thiol-terminated polymer PDMAEMA-SH. PDMAEMA coated GNPs (Au@PDMAEMA NPs) were synthesized in situ from HAuCl4 aqueous solution by using NaBH4 as a reductant and thiolated PDMAEMA as a stabilizer through Au–S bond. The optical and physical properties of GNPs were characterized by UV–Vis spectroscopy, transmission electron microscopy, X-ray diffraction as well as thermogravimetric analysis. The size and shape of GNPs could be controlled by tuning both the [PDMAEMA]:[HAuCl4] molar ratio and the solution pH. It is believed that these highly biocompatible GNPs have potential biomedical applications.