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

WS2 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 WS2 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 WS2 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 WS2 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 WS2 QDs was found in the urine samples when compared to feces, which confirmed the renal excretion route of the material. WS2 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 WS2 QDs are excellent candidate materials validated to be safe material for biomedical applications.

Automated summary

In this study, solvothermal liquid exfoliation method was used to synthesize bright green emissive WS2 QDs with excellent properties. The size and morphology were confirmed by HRTEM, and cytotoxicity analysis and radioactivity measurement showed biocompatibility and distribution of the QDs. ICP-MS analysis further confirmed the renal excretion route and lack of toxic response. This study proves that WS2 QDs are safe materials for biomedical applications.