Bimetallic CuMn nanozyme-enzyme microsystem for efficient dimethyl phthalate degradation.

Abstract

Recently, the synthesis of nanozymes-enzyme microsystems with high catalytic stability provides new opportunities for treating diverse pollutants in complex aquatic systems. Herein, a carboxyl-functionalized CuMn bimetallic nanozyme-enzyme microsystem (CMAC@Lipase) was successfully constructed by combining copper‑manganese based aminoclays (CMAC) with lipase. This system exhibited laccase-like catalytic activity facilitated by CuMn electron transfer, while enhancing lipase stability via its carrier function. Under alkaline conditions at pH 10, CMAC@Lipase catalyzed the hydrolysis of p-NPP (280 nm) to produce p-NP (400 nm), and subsequently reduced p-NP to p-AP within 30 min with the assistance of NaBH₄. Furthermore, it effectively degraded 72.8 % of dimethyl phthalate (DMP) at 40 mg·L^-1 under alkaline conditions within 48 h, maintaining a 53.5 % degradation rate after 10 reuse cycles. This work provided a new strategy for the design of nanozyme-enzyme microsystems and a new research idea for the efficient treatment of contaminants in actual aqueous environments.