Enhanced plant antioxidant capacity and biodegradation of phenol by immobilizing peroxidase on amphoteric nitrogen-doped carbon dots

A green method of immobilizing enzyme on biocompatible nitrogen-doped carbon dots (N-CDs) is proposed in this research. The N-CDs that were prepared in an environmentally friendly manner can improve plant antioxidant capacity to alleviate growth inhibition under stress. The fluorescence signal emitted by N-CDs present in vivo in plants indicates that N-CDs can immobilize peroxidase without a crosslinker. After immobilization, N-CDs-supported horseradish peroxidase (N-CDs@HRP) can significantly enhance peroxidase activity, stability, and phenol removal capacity when compared with free HRP. The N-CDs-immobilized enzyme with high activity and stability can be broadly applied to different environments and under harsh conditions.