title: Amperometric biosensor for the determination of phenolic compounds using a tyrosinase graphite electrode in a flow injection system.
abstract: Selective and sensitive devices for the monitoring of phenol and phenolic compounds are required in clinical and environmental analysis. This paper describes a biosensor for the analysis of phenolic compounds in a flow injection system. The enzyme electrode is based on the use of immobilized tyrosinase and the amperometric detection of the enzymatic product at -50 mV vs. SCE. The enzyme is covalently immobilized on the surface of a carbodiimide-activated graphite electrode. The biosensor responds to a variety of phenolic substrates with different conversion efficiencies. The detection limit for phenol is 0.003 microM (S/N = 3), a quantification limit of 0.01 microM (rsd 3.7%), and an extended dynamic range up to 5 microM is achieved with a sample frequency of 110 samples per hour.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of Alcalá de Henares, Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Ortega
authors.forename: E
authors.initials: E
authors.lastname: Domínguez
authors.forename: G
authors.initials: G
authors.lastname: Jönsson-Pettersson
authors.forename: L
authors.initials: L
authors.lastname: Gorton
mesh_terms: D015374:Biosensing Techniques; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006108:Graphite; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D010636:Phenols / Q000032:analysis*; D011199:Potentiometry / Q000295:instrumentation / Q000379:methods
chemical_list: D004800:Enzymes, Immobilized; D010636:Phenols; D006108:Graphite; D014442:Monophenol Monooxygenase