Novel biocompatible nanoreactor for silica/gold hybrid nanoparticles preparation

A new approach to the preparation of PEGylated [PEG: poly(ethylene glycol)] SiO2/Au hybrid nanoparticles was investigated. The synthesis of a PEGylated nanogel containing SiO2/Au hybrid nanoparticles was performed using matrix-catalyzed hydrolysis of tetraethyl orthosilicate, followed by the reduction of HAuCl4. UV–vis absorption of the prepared hybrid particles was obtained at 618 nm, which is a much longer wavelength than that of a nanogel containing only Au nanoparticles (523 nm). High-angle annular dark field images of the prepared particles observed using transmission electron microscopy and energy-dispersive X-ray spectroscopy confirmed the coexistence of Si and Au in the same particle. The presence of Si and Au in the prepared particles was also confirmed by inductively coupled plasma atomic emission spectroscopy. Dynamic light-scattering measurements of the particles in a highly ionic medium showed that they have high stability in both acidic and basic regions.