title: Investigation of biosensor signal bioamplification: comparison of direct electrochemistry phenomena of individual Laccase, and dual Laccase-Tyrosinase copper enzymes, at a Sonogel-Carbon electrode.
abstract: Direct electrochemistry of Trametes versicolor Laccase (LAC) was found at a Sonogel-Carbon electrode. The bioamplification, performed by dual immobilization of this enzyme and Mushroom Tyrosinase (TYR), of the bio-electrocatalytic reduction of O(2) was investigated. The calculated alpha transfer coefficients were 0.64 and 0.67, and the heterogeneous electron-transfer rate constants were 6.19 and 8.52 s(-1), respectively, for the individual LAC and dual LAC-TYR-based Nafion/Sonogel-Carbon bio-electrodes. The responses of the dual enzymes electrode to polyphenols were stronger than those of the individual LAC or TYR biosensors. Hypotheses are offered about the mechanism of bioamplification. The surfaces of the biosensors were also characterized by AFM.
authors.affiliation: Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Cadiz, Apdo. 40, 11510 Puerto Real, Cadiz, Spain.
authors.forename: Mohammed
authors.initials: M
authors.lastname: ElKaoutit
authors.forename: Ignacio
authors.initials: I
authors.lastname: Naranjo-Rodriguez
authors.forename: Khalid Riffi
authors.initials: KR
authors.lastname: Temsamani
authors.forename: Manuel
authors.initials: M
authors.lastname: Domínguez
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Hidalgo-Hidalgo de Cisneros
mesh_terms: D000465:Algorithms; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D004579:Electron Transport; D004800:Enzymes, Immobilized; D007700:Kinetics; D042845:Laccase / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D015203:Reproducibility of Results; D013499:Surface Properties
chemical_list: D004800:Enzymes, Immobilized; D002244:Carbon; D003300:Copper; D042845:Laccase; D014442:Monophenol Monooxygenase; D010100:Oxygen