Fabrication\nof Metallic-Ion-Free Fullerenols as Peroxidase-Like\nNanozymes to Stimulate Maize Early Growth

Although fabrication of various fullerenols as agronanozymes\nhas\nundergone remarkable expansion through employing various approaches,\nthere is a lack of knowledge regarding the understanding of metallic-ion-free\nfullerenols. A feasible preparation technology to fabricate metallic-ion-free\nfullerenols was developed by heating-treatment oversaturated fullerene\nusing H<sub>2</sub>O<sub>2</sub> solution in <i>o</i>-dichlorobenzene.\nIt was characterized as C<sub>60</sub>(OH)<sub>36</sub><b>·</b>9H<sub>2</sub>O by various measurements. Maize exposure of 50 mg/L\nC<sub>60</sub>(OH)<sub>36</sub><b>·</b>9H<sub>2</sub>O\nwas investigated to significantly enhance growth traits, including\nseed germination and seedling growth. Additionally, through the integration\nof ESR spectrum, radical scavenging assay, and peroxidase-like catalytic\nperformance <i>in vitro</i>, DAB staining to visualize the\naccumulated H<sub>2</sub>O<sub>2</sub> content <i>in vivo</i> as well as investigating the activation of antioxidative performance,\nit offers insights into the combinational action mechanism of C<sub>60</sub>(OH)<sub>36</sub><b>·</b>9H<sub>2</sub>O on crop\ngrowth regulation. C<sub>60</sub>(OH)<sub>36</sub><b>·</b>9H<sub>2</sub>O directly scavenged accumulated H<sub>2</sub>O<sub>2</sub> and indirectly activated the antioxidant system to suppress\nthe H<sub>2</sub>O<sub>2</sub> accumulation that acts like peroxidase\nactivity. The present study gives an updated knowledge on synthesizing\nmetallic-ion-free fullerenols with particular emphasis to their application\nas potential peroxidase-like nanozymes for regulatory roles in the\nimprovement of crop growth.