Synthesis of AIZS@SiO2 core–shell nanoparticles for cellular imaging applications

Abstract

I–III–VI₂ semiconductor nanoparticles such as AgInS₂ have been developed for cell imaging applications in recent years. However, there are few published works reporting the phase transfer (from hydrophobic to hydrophilic) of the AgInS₂ nanoparticles for biomedical application purposes. In this work, we report the successful silica coating for the as-synthesized Zn-doped AgInS₂ (AIZS) nanoparticlesvia a templated coating route. The silica shell thickness of the obtained AIZS@SiO₂ core–shell nanoparticles could be well controlled within 10–20 nm and their overall size was less than 50 nm. As compared to the AIZS nanoparticles stabilized by cetyltrimethylammonium bromide (CTAB), the obtained AIZS@SiO₂ nanoparticles showed much improved photoluminescence (PL) stability in water. The obtained core–shell nanoparticles were further conjugated with the PEG functional group, and the resultant PEGylated nanoparticles showed excellent colloidal stability in various media such as water, phosphate buffered saline (PBS) and bovine calf serum (BCS). The cellular imaging application of the obtained AIZS@SiO₂ nanoparticles was also demonstrated successfully.