Hemin-Block Copolymer Micelle as an Artificial Peroxidase and Its Applications in Chromogenic Detection and Biocatalysis

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• 作者：Rui Qu ; Liangliang Shen ; Zhihua Chai ; Chen Jing ; Yufeng Zhang ; Yingli An ; Linqi Shi
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：November 12, 2014
• 年：2014
• 卷：6
• 期：21
• 页码：19207-19216
• 全文大小：467K
• ISSN：1944-8252

文摘

Following an inspiration from the fine structure of natural peroxidases, such as horseradish peroxidase (HRP), an artificial peroxidase was constructed through the self-assembly of diblock copolymers and hemin, which formed a functional micelle with peroxidase-like activity. The pyridine moiety in block copolymer poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG-b-P4VP) can coordinate with hemin, and thus hemin is present in a five-coordinate complex with an open site for binding substrates, which mimics the microenvironment of heme in natural peroxidases. The amphiphilic core鈥搒hell structure of the micelle and the coordination interaction of the polymer to the hemin inhibit the formation of hemin 渭-oxo dimers, and thereby enhance the stability of hemin in the water phase. Hemin-micelles exhibited excellent catalytic performance in the oxidation of phenolic and azo compounds by H₂O₂. In comparison with natural peroxidases, hemin-micelles have higher catalytic activity and better stability over wide temperature and pH ranges. Hemin-micelles can be used as a detection system for H₂O₂ with chromogenic substrates, and they anticipate the possibility of constructing new biocatalysts tailored to specific functions.

Keywords:

hemin; block copolymer; micelle; coordination; artificial peroxidase