Evaluation of biodistribution and kinetics of tungsten disulphide quantum dots by Inductively coupled plasma mass spectroscopy: A detailed in vivo QD-bio interactions study.

WS QDs are inorganic semiconductor nanocrystals which belong to the family of transition metal dichalcogenides (TMDC). As toxic heavy metal free quantum dots, TMDC based QDs is gaining attention due to excellent chemical stability, good thermal conductivity and stable optical properties. In the present study, bright green emissive and excellent WS QDs was synthesized by solvothermal liquid exfoliation method using NMP solvent. The size and morphology were confirmed by HRTEM (3-4 nm, spherical). Illumination by 370 nm UV source showed bright green fluorescence due to the excellent quantum confinement effect. The as synthesised WS QDs exhibits excellent properties such as stable dispersion, extreme low cytotoxicity as well as fluorescent properties, which makes them suitable candidates for optoelectronic and biological applications. Cytotoxicity analysis via NRU assay confirmed the low cytotoxic potential. Subcellular localization confirmed the distribution of WS QDs around the nucleus. Spleenocyte proliferation via radioactivity measurement showed lack of any immune response. ICP-MS analysis showed that a significant amount of the administered WS QDs was found in the urine samples when compared to feces, which confirmed the renal excretion route of the material. WS QDs didnot evoke any evident toxic response upto 10 mg/kg body weight i.p administration. Excellent fluorescence property shown by this material marked its prominence in in vitro/ in vivo imaging and other biomedical applications. The study proved that WS QDs are excellent candidate materials validated to be safe material for biomedical applications.