Fluorescent-stable and water-soluble two-component-modified silicon quantum dots and their application for bioimaging

Increasing the fluorescence intensity and water solubility of silicon quantum dots (Si QDs) is of great importance for their application in biological imaging. Herein, SiQDs are prepared via electrochemical etching method and modified with two components of glutamate and polyvinyl pyrrolidone (PVP). Glutamate increases the fluorescence intensity and PVP enhances the dispersion of SiQDs. The synergistic effect endows the two-component-modified SiQDs with high photoluminescent quantum yield up to 23.22%. The fluorescence shows high stability with no obvious quenching after one month storage in ambient atmosphere. The low toxicity makes the two-component-modified SiQDs a proper probe for bioimaging.