Effect of UV radiation on the toxicity of imidacloprid and imidacloprid nanoribbons in Drosophila melanogaster

Previous investigations reported on the toxic effects of imidacloprid (IMC) nanoribbons (IMCNR), synthesized by laser fragmentation/exfoliation in liquid media. In Drosophila melanogaster, chronic or acute treatment with IMCNR significantly reduced olfactory responses, climbing ability, and lifespan compared to bulk IMC treatment. However, no marked differences were observed in productivity or induction of genetic damage between these two formulations. The aim of the present study was to examine the toxicity of IMCNR subjected to ultraviolet (UV) light on D. melanogaster. For this purpose, solutions of IMC and IMCNR corresponding to LC50 (0.55 and 0.02 ppm, respectively) were exposed to UV light (254 nm) for 20, 40, 60, and 120 min. These irradiated solutions were used for chronic treatment of second-instar larvae. In addition, solutions containing 5, 10, or 15 ppm of both formulations (IMC and IMCNR) were UV-irradiated for 60 min and subsequently administered to adults. Data demonstrated that UV-irradiated formulations initiate the following effects on D. melanogaster: (1) significantly increased survival in both larval and adult stages; (2) improved olfactory responses, climbing ability, and productivity in adults; (3) no marked alteration in lifespan compared to IMC or IMCNR controls; and (4) reduced genotoxic potential to basal levels only after 120 min exposure. These findings suggest that UV irradiation of both formulations mitigates toxic and genotoxic effects.