Surface modification of CdS quantum dots: An effective approach for improving biocompatibility

The surface of Quantum Dots (QDs) decides the influence of their performance in biomedical, sensing as well as in photocatalysis applications. Herein, we report a surface modification of Cadmium sulfide (CdS) QDs in the presence of Vanadium pentoxide (V₂O₅) denoted as CdS@V₂O₅, by single-source inorganic cluster approach. The X-Ray Diffraction (XRD) pattern, Photoluminescence (PL) spectra, Raman spectra as well as biocompatibility results strongly indicate the surface modification of CdS QDs. XRD pattern of CdS@V₂O₅ QDs shows a crystal structural phase change from Zinc blende to Wurtzite, which was further confirmed by high-resolution TEM and selected area electron diffraction pattern. Biocompatibility test with MCF-10A and HeLa cell lines with optimized dosages of CdS and CdS@V₂O₅ QDs were carried out, and results show a significant enhancement in the viability of cell lines for CdS@V₂O₅ QDs, whereas cell lines exposed to CdS QDs has negligible viability. The enhancement in biocompatibility of CdS@V₂O₅ QDs may be due to bond formation between Cd dangling bond and V₂O₅. The optimized dosages of CdS@V₂O₅ QDs can prove very useful application in biomedical science.