Gelatin stabilized mesoporous silica CuInS₂/ZnS nanocomposite as a potential near-infrared probe and their effect on cancer cell lines

Ternary quantum dots (QDs) are promising inorganic fluorescent probes, especially for bioimaging and optical detection. However, the long-term stability and photostability of these QDs are still challenging. We herein report the synthesis of gelatin (Gel) stabilized mesoporous silica-(Santa Barbara Amorphous (SBA 15)) encapsulated CuInS₂/ZnS quantum dots- (SBA-QDs) and its cell viability against A549 and Hela cell lines. The as-synthesized Gel-SBA-QDs composites exhibited improved quantum yield (QY) and high photostability. FTIR spectroscopy and surface charge analysis confirmed the effective capping of gelatin on the SBA QDs. The long-term stability of the SBA QDs was greatly enhanced after the gelatin modification. The TEM analysis confirmed that the material retained its rod shape and ordered pores even after gelatin stabilization. The Gel-SBA-QDs exhibited a photoactivation mechanism where the emission intensity of the composite increased upon exposure to UV light. The cytotoxicity assay indicated that the Gel-SBA-QDs showed good viability against the A549 cell line and dose-dependent viability against the Hela cell line. The improved optical properties, stability, and good cell viability characteristics present the as-synthesized Gel-SBA-QDs as an ideal material for theragnostic applications.