title: Phenols monitoring and Hill coefficient evaluation using tyrosinase-based amperometric biosensors.
abstract: Sensitive amperometric biosensors for phenols compounds, based on tyrosinase (polyphenoloxidase, PPO) immobilized on a Pt electrode in an electropolymerized poly-amphiphilic pyrrole matrix or cross-linked with glutaraldehyde, were constructed and compared. Steady-state amperometric measurements, performed at -50 mV vs. SCE in aqueous phosphate buffer containing LiClO(4) 0.1 M (pH 7) as well as in a chloroform solution containing 0.1 M C(6)H(5)CH(2)N(CH(3))(3)Cl, were used in order to compare the electroanalytical and kinetic parameters of the investigated amperometric biosensors in aqueous and nonaqueous media. It was established that the polypyrrole matrix has a higher efficiency for enzyme retention resulting in higher bioelectrode sensitivity, both in aqueous buffer (690 microA M(-1)) and in chloroform (149 microA M(-1)).
authors.affiliation: Department of Physics, Chemistry and Informatics, Faculty of Environmental Protection, University of Oradea, 3700 Oradea, Romania. sarmiza.stanca@ucd.ie
authors.forename: Sarmiza Elena
authors.initials: SE
authors.lastname: Stanca
authors.forename: Ionel Catalin
authors.initials: IC
authors.lastname: Popescu
mesh_terms: D019817:Benzoic Acid / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D002138:Calibration; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005069:Evaluation Studies as Topic; D005976:Glutaral / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D010636:Phenols / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011199:Potentiometry; D011758:Pyrroles / Q000737:chemistry; D012680:Sensitivity and Specificity; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D010636:Phenols; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D010984:Platinum; D019817:Benzoic Acid; D014442:Monophenol Monooxygenase; D005976:Glutaral