title: Effective immobilization of tyrosinase via enzyme catalytic polymerization of l-DOPA for highly sensitive phenol and atrazine sensing.
abstract: The facile preparation of poly(l-DOPA)-tyrosinase (PDM-Tyr) composite and its application both in substrate (phenol) and inhibitor (atrazine) sensing is reported here for the first time. Effective immobilization of enzyme is realized via in-situ entrapping Tyr in poly(l-DOPA) (PDM), which is formed by Tyr catalytic polymerization of l-DOPA. The Tyr modified electrode is simply prepared by dipping the PDM-Tyr composite on an Au electrode and then covered by Nafion. The thus-prepared Tyr-immobilized electrode exhibits excellent performance superior to most Tyr-based electrochemical biosensors, the sensitivity to phenol is as high as 5122 μA mM(-1) in the linear range of 10nM~1.25 μM, the apparent Michaelis-Menten constant (KM(app)) determined as low as 3.13μM indicates strong substrate binding and high catalytic activity of the immobilized Tyr. The biosensor also works well in atrazine biosensing, with a linear detection range of 50ppb~30ppm and a low detection limit of 10ppb obtained. In addition, the biosensor shows excellent stability, precision, high sensitivity and fabrication simplicity.
authors: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors: Yun
authors: Y
authors: Guan
authors: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors: Lanjunzi
authors: L
authors: Liu
authors: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China. Electronic address: chenchao840103@163.com.
authors: Chao
authors: C
authors: Chen
authors: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China.
authors: Xiuzhi
authors: X
authors: Kang
authors: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China. Electronic address: xieqj@hunnu.edu.cn.
authors: Qingji
authors: Q
authors: Xie
mesh_terms: D001280:Atrazine / Q000032:analysis* / Q000737:chemistry; D015374:Biosensing Techniques; D002384:Catalysis; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000737:chemistry; D055664:Electrochemical Techniques; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005465:Fluorocarbon Polymers / Q000737:chemistry; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000737:chemistry*; D019800:Phenol / Q000032:analysis* / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D005465:Fluorocarbon Polymers; D011108:Polymers; C539838:poly(3,4-dihydroxyphenylalanine); D019800:Phenol; C040402:perfluorosulfonic acid; D004295:Dihydroxyphenylalanine; D014442:Monophenol Monooxygenase; D001280:Atrazine
keywords: Atrazine biosensing; Enzyme-catalyzed polymerization; L-DOPA; Phenolic compounds biosensing; Tyrosinase modified electrode