Nanofabrication of graphene quantum dots with high toxicity against malaria mosquitoes, Plasmodium falciparum and MCF-7 cancer cells. Impact on predation of non-target tadpoles, odonate nymphs and mosquito fishes

Recently, it has been highlighted an overlooked connection between the biting activity of Anopheles mosquitoes and the spread of cancer. The excellent physico-chemical properties of graphene quantum dots (GQDs) make them a suitable candidate for biomedical applications. We focused on the toxicity of GQDs against Plasmodium falciparum and its vector Anopheles stephensi, and their impact on predation of non-target mosquito predators. Biophysical methods, including UV–vis, photoluminescence, FTIR and Raman spectroscopy, XRD analysis and TEM, confirmed the effective GQD nanosynthesis. LC50against A. stephensi ranged from 0.157 (larva I) to 6.323 ppm (pupa). The antiplasmodial activity of GQDs was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of P. falciparum. IC50were 82.43 (CQ-s) and 85.17 μg/ml (CQ-r). In vivo experiments conducted on Plasmodium berghei infecting albino mice showed moderate activity of GQDs if compared to chloroquine. Concerning non-target effects, the predation efficiency of Gambusia affinis, Anax immaculifrons and Hoplobatrachus tigerinus post-treatment with GQDs was enhanced. Lastly, GQDs were toxic against MCF-7 breast cancer cell lines with an IC50 = 24.81 μg/ml, triggering apoptosis in treated cells. Overall, we highlighted the multipurpose potential of GQDs for the development of newer drugs in the fight against Anopheles vectors, Plasmodium parasites and breast cancer cells.