title: Laccase Inhibition by Arsenite/Arsenate: Determination of Inhibition Mechanism and Preliminary Application to a Self-Powered Biosensor.
abstract: The reversible inhibition of laccase by arsenite (As(3+)) and arsenate (As(5+)) 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.
authors: Departments of Chemistry and Materials Science and Engineering, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States.
authors: Tao
authors: T
authors: Wang
authors: Departments of Chemistry and Materials Science and Engineering, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States.
authors: Ross D
authors: RD
authors: Milton
authors: Departments of Chemistry and Materials Science and Engineering, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States.
authors: Sofiene
authors: S
authors: Abdellaoui
authors: Departments of Chemistry and Materials Science and Engineering, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States.
authors: David P
authors: DP
authors: Hickey
authors: Departments of Chemistry and Materials Science and Engineering, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States.
authors: Shelley D
authors: SD
authors: Minteer
mesh_terms: D001149:Arsenates / Q000494:pharmacology*; D018053:Arsenites / Q000494:pharmacology*; D015374:Biosensing Techniques; D042845:Laccase / Q000037:antagonists & inhibitors*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001149:Arsenates; D018053:Arsenites; D042845:Laccase; C015001:arsenite; C025657:arsenic acid