Evaluation of the toxic and genotoxic effects of exposure of Drosophila melanogaster to the glutathione-capped AgIn5Se8@ZnS nanocrystals

Silver indium selenide - AgIn₅Se₈ (AISe) quantum dots (QDs) are emerging as a safe alternative to cadmium-containing QDs, particularly for biomedical applications such as imaging, probing individual molecules, and photodynamic therapy cancer. However, research on the toxicity and health risks of AISe QDs remains limited. This study aimed to evaluate the safety of AISe QDs, synthesized through green aqueous electrosynthesis, coated with zinc sulphide (ZnS), and stabilized with l-glutathione (GSH). To assess potential nanotoxicity, third-instar Drosophila melanogaster larvae were fed a standard diet supplemented with AISe@ZnS QDs at concentrations of 10, 50, 150 and 300 μg/mL for 24 h. Parameters evaluated included toxicity (survival, negative geotaxis, phenotypic analysis), oxidative stress (lipid peroxidation (MDA), total (PSH) and non-total (NPSH) protein content, free iron (Fe²⁺) levels), and genotoxicity (Comet assay). No evidence of toxicity, induction of oxidative stress and primary DNA damage (Comet assay) was observed in D. melanogaster larvae exposed to these QDs. This study demonstrates the biocompatibility of AISe@ZnS QDs and indicates that they do not present toxicity or genotoxicity to D. melanogaster, reinforcing the importance of further studies into their safety and applications.