Laccase Inhibition by Arsenite/Arsenate: Determination of Inhibition Mechanism and Preliminary Application to a Self-Powered Biosensor
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- 作者：Tao Wang ; Ross D. Milton ; Sofiene Abdellaoui ; David P. Hickey ; Shelley D. Minteer
- 刊名：Analytical Chemistry
- 出版年：2016
- 出版时间：March 15, 2016
- 年：2016
- 卷：88
- 期：6
- 页码：3243-3248
- 全文大小：445K
- ISSN：1520-6882
文摘
The reversible inhibition of laccase by arsenite (Asp>3+ p>) and arsenate (Asp>5+ p>) is reported for the first time. Oxygen-reducing laccase bioelectrodes were found to be inhibited by both arsenic species for direct electron-transfer bioelectrodes (using anthracene functionalities for enzymatic orientation) and for mediated electron-transfer bioelectrodes [using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as an electron mediator]. Both arsenic species were determined to behave via a mixed inhibition model (behaving closely to that of uncompetitive inhibitors) when evaluated spectrophotometrically using ABTS as the electron donor. Finally, laccase bioelectrodes were employed within an enzymatic fuel cell, yielding a self-powered biosensor for arsenite and arsenate. This conceptual self-powered arsenic biosensor demonstrated limits of detection (LODs) of 13 μM for arsenite and 132 μM for arsenate. Further, this device possessed sensitivities of 0.91 ± 0.07 mV/mM for arsenite and 0.98 ± 0.02 mV/mM for arsenate.