| 초록 |
We demonstrate computationally designed metal-free nanozymes that mimic peroxidase and catalase depending on the pH condition. Based on a zero-dimensional carbon matrix, fullerene, N and B are doped to form active sites for reactive oxygen species. Under neutral condition, both N- and B-doped fullerenes (NF and BF) show peroxidase-like activity. Ab-initio molecular dynamics (AIMD) reveal the stability of both structures under solvation, and possible catalase-like activity of BF where B atom functions as a strong electrophile to firmly adsorb OOH*. Interestingly, under acidic and basic environment, they show selective peroxidase- and oxidase-like activity, respectively, with the help of pre-adsorbed H* and OH*. The oxidation reaction energy profiles for ascorbic acid and 3,3’,5,5’-Tetramethylbenzidine (TMB) show that of NF and BF significantly decrease the dissociation energy of H2O2 into 2OH and so lower the reaction energy barrier. The results can provide useful guide for designing highly active and selective all-organic nanozymes, bypassing those constructed with metal species. |
