Microwave‐Assisted Synthesis Method for the Production of Carbon Nano Dots and Its Genotoxicity Assessment

Abstract In this study, nitrogen‐doped carbon nanodots (N‐CNDs) were synthesized from Citrus reticulata using microwave‐assisted process and material's genotoxic effects were investigated in Daphnia magna . Morphological size and shape variations of the synthesized N‐CNDs were evaluated by using zetasizer and transmission electron microscope. Acute/chronic toxicity experiments were performed using method by OECD (Organization for Economic Cooperation and Development) 202–212 guidelines. Daphnia magna was subjected to the N‐CNDs produced from Citrus reticulata at the different concentrations ranging between 0.04 and0.24 mg tangerine equivalent N‐CND/mL for 96 h at 20 °C. After 96 h, the LC 50 (lethal concentration‐ at which 50% of cells) value of N‐CNDs was determined to be 0.1 mg equivalent N‐CND/mL using probit analysis. Based on toxicity levels determined by EU‐Directive 93/67/EEC, N‐CNDs are classified in the nontoxic category. The toxicological assessments of sublethal concentrations of N‐CNDs demonstrated that 0.013 mg tangerine equivalent N‐CND/mL dose group exhibited a similar profile to the control group, indicating its safety. Although the DNA damage frequency of the 0.03 and 0.06 mg equivalent N‐CND/mL dose groups was found to be higher than control group, these levels were observed almost 70% lower than the DNA damage frequency found in the mutagenic group/positive group.