Tailoring the Synthesis Route of Reduced Graphene Oxide and Its Toxicological Effects on Allium cepa L.

The synthesis and use of reduced graphene oxide (RGO) have increased recently due to its numerous applications in drug delivery systems, regenerative medicine, fertilizers, antibacterial agents, and biosensors. Consequently, large quantities of RGO are deposited in the environment through industrial wastewater or agricultural products, whereupon they are liable to contaminate farming lands and soils in general. In this work, RGO was synthesized using two different reducing agents, namely, sodium borohydride (conventional reductant; RGO-I) and sucrose, (green reductant; RGO-II) and characterized using various microscopic and spectroscopic techniques. Subsequently, onion roots were exposed to RGO at different concentrations (1, 10, and 100 mg L) and various toxicity assessments were performed. The toxicity of RGO increased potentially as a function of the concentration. Notably at 100 mg L, RGO-I exhibited a maximum of 48% phytotoxicity with significant ( < 0.001) genotoxic effects, while RGO-II exhibited a 21% reduction in cell viability with no significant ( > 0.05) genotoxic effects. The findings from this study demonstrated the potential benefits of synthesizing RGO through safer and more sustainable methods to improve agricultural applications.