Highly stable and bio-compatible luminescent molybdenum disulfide quantum dots for imaging of alimentary canal in Drosophila

Abstract

Investigations on inorganic luminescent nanomaterials have always gained enormous attention of the science community for their possible applications in the fields of bioimaging and biomedicine. In this succession, various 0D structures including CdSe, CdTe, ZnS, graphene quantum dots (GQDs), carbon nanodots (CNDs) etc. have been explored for their possible applications in the field of biology. Recently, molybdenum disulfide quantum dots (MoS2-QDs) have been explored as an alternative of graphene quantum dots (GQDs) for their possible applications in relevant fields. Herein we report a facile, eco-friendly and single step hydrothermal synthesis of in-situ functionalized molybdenum disulfide quantum dots (f-MoS2-QDs). During the synthesis, variation in the pH of the starting solution provided the controlling over particle size. These as synthesized f-MoS2-QDs have shown excitation dependent broad emission spectra, which could be fitted for a parabolic function. The broadening in the emission spectra might be attributed to the polydispersity of f-MoS2-QDs in colloidal suspension, which was further confirmed with time resolved photoluminescence (TRPL) measurement. Due to surface capping provided by various functional groups present in the colloidal suspension, f-MoS2-QDs have shown excellent stability in aqueous medium and only a 3% of decrement in PL intensity was recorded even after six months. These synthesized f-MoS2-QDs possessed a quantum yield (QY) of 2.3% in aqueous media. Due to their high photostability and biocompatibility, these f-MoS2-QDs have been revealed as a potential entrant for in vivo bioimaging in Drosophila.