Abstract: In this study, silk sericin(SS) was modified by Cu(II) chelation to prepare Cu@SS with peroxidase (POD)-like activity for the reuse of sericin. The effect of Cu(II) on the structure of sericin and the catalytic performance, biocompatibility and antibacterial activity of Cu@SS nanozymes were studied. The results showed that Cu@SS nanozymes had POD-like activity, and their Michaelis constants ( $ K_{m} $) for 3,3',5,5'-tetramethylbenzidine(TMB) and hydrogen peroxide( $ H_{2}O_{2} $) were $ 1.965 \times 10^{-4} $ mol/L and $ 1.238 \times 10^{-3} $ mol/L, respectively. Cell experiments showed that Cu@SS nanozymes had good biocompatibility and no cytotoxicity against macrophage RAW 264.7 cells. Furthermore, Cu@SS nanozymes reduced the relative bacterial viability of Escherichia coli to 45% in the presence of $ H_{2}O_{2} $. Therefore, Cu@SS nanozyme is a good biocompatible material with favorable antibacterial properties.
Keywords: silk sericin(SS); Cu(Ⅱ) nanozymes; peroxidase(POD)-like activity; biocompatibility; antibacterial property