Aqueous glutathione-capped Bi2S3-GSH nanocrystals: Electrosynthesis and biological toxicity assessment

Bismuth-based quantum dots (QDs) are promising materials due to their potential applications in energy conversion and medical therapy. Compared to other metals, such as silver, their large-scale production is more feasible, making them particularly attractive for biomedical and nanotechnological applications. However, despite their advantages, it is crucial to investigate their potential toxic effects on living organisms. This study aimed to characterize the physicochemical properties and evaluate the in vitro cytotoxic and genotoxic effects of Bi 2 S 3 -GSH nanocrystals (glutathione-capped Bi 2 S 3 nanocrystals). Characterization techniques included UV-Vis spectroscopy, X-ray diffractometry, zeta potential analysis, and transmission electron microscopy. Additionally, MTT and cytokinesis-block micronucleus (CBMN) assays were performed to assess cytotoxicity (concentrations from 3.9 to 125 μg.mL -1 ) and genotoxicity (concentrations from 15.62 to 125 μg.mL -1 ) in the Vero E6 normal cell line. Transmission electron microscopy analysis revealed that Bi 2 S 3 -GSH nanocrystals exhibited low crystallinity due to their small particle size (2.61 nm). Despite their polydispersity, a normal size distribution indicated uniform nanocrystal formation. Regarding cytotoxicity, Bi 2 S 3 -GSH showed no cytotoxic effects, while the CBMN assay revealed genotoxicity for Bi 2 S 3 -GSH only at the highest concentration (125 μg.mL -1 ), emphasizing its potential for biomedical and nanotechnological applications at low concentrations.