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

Abstract

Recently, in situ detection of hydrogen peroxide (H 2 O 2 ) generated from live cells have caused tremendous attention, because it is of great significance in the control of multiple biological processes. Herein, Fe–N–C single-atom nanozymes (Fe–N–C SAzymes) with intrinsic peroxidase-like activity were successfully prepared via high-temperature calcination using FeCl 2, glucose, and dicyandiamide as precursors. The Fe–N–C SAzymes with FeN x as active sites were similar to natural metalloproteases, which can specifically enhance the peroxidase-like activity rather than oxidase-like activity. Accordingly, owing to the excellent catalytic efficiency of the Fe–N–C SAzymes, colorimetric biosensing of H 2 O 2 in vitro was performed via a typical 3,3′,5,5′-tetramethylbenzidine induced an allochroic reaction, demonstrating the satisfactory specificity and sensitivity. With regard to the practical application, in situ detection of H 2 O 2 generated from the Hela cells by the Fe–N–C SAzymes was also performed, which can expand the applications of the newborn SAzymes.