Fe–N–C Single-Atom Nanozymes for the\nIntracellular Hydrogen Peroxide Detection

Abstract

Recently, in situ\ndetection of hydrogen peroxide (H₂O₂) generated\nfrom live cells have caused tremendous attention,\nbecause it is of great significance in the control of multiple biological\nprocesses. Herein, Fe–N–C single-atom nanozymes (Fe–N–C\nSAzymes) with intrinsic peroxidase-like activity were successfully\nprepared via high-temperature calcination using FeCl₂,\nglucose, and dicyandiamide as precursors. The Fe–N–C\nSAzymes with FeN_<i>x</i> as active sites were\nsimilar to natural metalloproteases, which can specifically enhance\nthe peroxidase-like activity rather than oxidase-like activity. Accordingly,\nowing to the excellent catalytic efficiency of the Fe–N–C\nSAzymes, colorimetric biosensing of H₂O₂ in\nvitro was performed via a typical 3,3′,5,5′-tetramethylbenzidine\ninduced an allochroic reaction, demonstrating the satisfactory specificity\nand sensitivity. With regard to the practical application, in situ\ndetection of H₂O₂ generated from the Hela cells\nby the Fe–N–C SAzymes was also performed, which can\nexpand the applications of the newborn SAzymes.