Synthesis and Photoluminescence Properties of Water-Soluble ZnS Quantum Dots for Biomarkers

Abstract

Abstract In this work, we investigated the effects of the surfactant L-cysteine (L-cys) and folic acid (FA) on photoluminescence (PL) properties, water-solubility and biotoxicity of ZnS quantum dots (QDs). It was found that capping L-cys improved the water-solubility of ZnS QDs. The emission intensity of ZnS QDs was found to be also enhanced after capping with Lcys, The maximum emission intensity of ZnS capped with L-cys QDs was about 4.5 times stronger than the uncapped ZnS QDs. FA decreased the PL intensity of L-cys/ZnS QDs and increased water-solubility the of L-cys/ZnS QDs. The L-cys/ZnS and FA@ L-cys/ZnS quantum dots were proved to be nontoxic by the MTT assay.