Laser-Induced N- and B-Codoped Graphene Nanozymes with Intrinsic Peroxidase-Like Activities for Bactericidal Application

Abstract

Conventional heteroatom-doped graphene oxide (GO) nanozymes usually suffer from complicated manufacturing processes and difficult recovery of nanozymes. Herein, a facile and ecofriendly approach is developed to write nitrogen- and boron-codoped GO nanozyme patterns on a flexible plastic film by CO2 laser scanning in ambient air without any catalyst, mask, or template. The resulting N-doped laser-induced graphene (LIG) with a hierarchical porous and hydrophilic interface possesses intrinsic peroxidase-like activities in catalyzing the typical chromogenic reaction of 3,3′,5,5′-tetramethylbenzidine, denoted as N-doped LIG nanozyme (N-LIGzyme). Further compositional modification with boron atoms doped into N-LIGzyme (N,B-LIGzyme) produces a significant and specific enhancement for the peroxidase-mimetic activity with good reproducibility, high stability, and acceptable recyclability. Owing to the high peroxidase-like activity of N,B-LIGzyme that could convert H2O2 into a hydroxyl radical (•OH), N,B-LIGzyme shows enhanced bactericidal ability against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. It is expected that the proposed facile and green synthesis of N,B-LIGzyme atop flexible plastic films will not only open up an exciting vista in the novel applications of classical LIG but also provide a new avenue to design flexible nanozymes with excellent catalytic activity, good operational stability, and easy separation.