Simultaneous Enhancement of Bioactivity and Stability of Laccase by Cu2+/PAA/PPEGA Matrix for Efficient Biosensing and Recyclable Decontamination of Pyrocatechol

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• 作者：Tao Chen ; Yuanhong Xu ; Zhi Peng ; Aihua Li ; Jingquan Liu
• 刊名：Analytical Chemistry
• 出版年：2017
• 出版时间：February 7, 2017
• 年：2017
• 卷：89
• 期：3
• 页码：2065-2072
• 全文大小：519K
• ISSN：1520-6882

文摘

Simultaneously enhancing the catalytic bioactivity and stability of enzyme is still an intractable issue in the enzymatic study. Herein, a facile and effective approach was designed to immobilize and modify laccase on a Cu²⁺-adsorbed pyrene-terminated block copolymer [poly(acrylic acid)/poly(poly(ethylene glycol) acrylate)] (PAA/PPEGA), which was prepared via well-controlled reversible addition–fragmentation chain transfer polymerization. PAA provided the supporting matrix for firm immobilization of Cu²⁺, an enzyme bioactivity inducer, onto the microstructure of laccase, while avoiding any contamination of the heavy metal Cu²⁺ into the following application system. The water-soluble, biocompatible, and nontoxic PPEGA was used as an ideal modifier to improve the laccase stability. Accordingly, the modified laccase exhibited enhanced catalytic bioactivity and stability simultaneously to 447% and 237%, respectively. The modified laccase was immobilized on the highly oriented pyrolytic graphite surface and large-area graphene papers through π–π stacking interactions between the pyrene moiety of PAA/PPEGA and the π-conjugated graphenelike surface. The as-prepared portable solid-state electrochemical laccase biosensor showed lowest detection limit of 50 nM (S/N ≥ 3) and long-term stability for pyrocatechol detection. Besides, the laccase immobilization on graphene paper provided efficient pyrocatechol decontamination platform with convenience and recyclability, which could retain the laccase bioactivity of 176% after 8 consecutive operations.