Electrochemical generation of Fe3C/N-doped graphitic carbon nanozyme for efficient wound healing in vivo

The emergence of antibiotic resistance has been advancing the exploration of highly-efficient, cost-effective and biocompatible enzymatic nanomaterials (i.e. nanozyme) as antibacterial agents. Iron carbide (Fe3C) based nanomaterials were suggested to be promising catalysts as well as nanozymes, but were limited with the low enzyme-like activity and the high temperature-carbonization, time-consumption preparation process. Herein, one efficient peroxidase-like Fe3C/N-doped graphitic carbon nanomaterial (Fe3C/N–C) was prepared through a one-step mild electrochemical method. Therein, the FeSO4/histidine (His) mixture and graphite rod were used as the electrolyte and the electrode, respectively. The generation of Fe3C/N–C was coincidentally benefiting from the specific affinity interactions between the His derived carbon nanodots (CNDs) and the iron ion. The Fe3C/N–C nanozyme could enable the decomposition of hydrogen peroxide (H2O2) to hydroxyl radical (•OH), resulting in higher broad-spectrum antimicrobial activity than H2O2 alone. Accordingly, high concentration of H2O2 can be avoided in bacterial infection, but accelerated wound healing in vivo can be achieved simultaneously. The superior peroxidase-like ability can be attributed to the intrinsic active sites in the Fe3C while using the carbon nanosheets as the matrix. And the synergistic interface effect between Fe3C and N-doped graphite carbon could lead to the enhancement of peroxidase mimicking activity in return.