One-pot hydrothermal synthesis of metal-doped carbon dot nanozymes using protein cages as precursors

Metal-doped carbon dots represent a new class of promising nanomaterials with enzyme-like activity, whose properties such as fluorescence properties and enzyme-like activity are determined by the precursors and the conditions used to prepare them. Nowadays, the synthesis of carbon dots using naturally occurring precursors has attracted increasing attention. Here, using metal-loaded horse spleen ferritin as a precursor, we report a facile one-pot hydrothermal strategy to synthesise metal-doped fluorescent carbon dots with enzyme-like activity. The as-prepared metal-doped carbon dots exhibit high water solubility, uniform size distribution, and good fluorescence. In particular, the Fe-doped carbon dots exhibit prominent oxidoreductase catalytic activities, including peroxidase-like, oxidase-like, catalase-like, and superoxide dismutase-like activities. This study provides a green synthetic strategy for developing metal-doped carbon dots with enzymatic catalytic activity.