title: Disposable tyrosinase-peroxidase bi-enzyme sensor for amperometric detection of phenols.
abstract: A new disposable amperometric bi-enzyme sensor system for detecting phenols has been developed. The phenol sensor developed uses horseradish peroxidase modified screen-printed carbon electrodes (HRP-SPCEs) coupled with immobilized tyrosinase prepared using poly(carbamoylsulfonate) (PCS) hydrogels or a poly(vinyl alcohol) bearing styrylpyridinium groups (PVA-SbQ) matrix. Optimization of the experimental parameters has been performed with regard to buffer composition, pH, operating potential and storage stability. A co-operative reaction involving tyrosinase and HRP occurs at a potential of -50 mV versus Ag/AgCl without the requirement for addition of extraneous H(2)O(2), thus, resulting in a very simple and efficient system. Comparison of the electrode responses with the 4-aminoantipyrine standard method for phenol sample analysis indicated the feasibility of the disposable sensor system for sensitive "in-field" determination of phenols. The most sensitive system was the tyrosinase immobilized HRP-SPCE using PCS, which displayed detection limits for phenolic compounds in the lower nanomolar range e.g. 2.5 nM phenol, 10 nM catechol and 5 nM p-cresol.
authors.affiliation: School of Clinical and Laboratory Sciences, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Seung Cheol
authors.initials: SC
authors.lastname: Chang
authors.forename: Keith
authors.initials: K
authors.lastname: Rawson
authors.forename: Calum J
authors.initials: CJ
authors.lastname: McNeil
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002138:Calibration; D002244:Carbon; D004209:Disposable Equipment; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D006735:Horseradish Peroxidase / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D014442:Monophenol Monooxygenase / Q000737:chemistry; D009097:Multienzyme Complexes / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D004800:Enzymes, Immobilized; D009097:Multienzyme Complexes; D010636:Phenols; D014874:Water Pollutants, Chemical; D002244:Carbon; D006735:Horseradish Peroxidase; D014442:Monophenol Monooxygenase