title: Bi-enzyme sensor based on thick-film carbon electrode modified with electropolymerized tyramine.
abstract: Bi-enzyme sensor based on thick-film epoxy-carbon electrode modified with polytyramine has been developed and examined for the determination of peroxidase substrates and cholinesterase inhibitors. Polytyramine was obtained on the electrode surface by repeated scanning of the potential from +600 to +1800 mV vs. Ag/AgCl in tyramine solution. The enzymes were immobilized in the polytyramine matrix by cross-linking with glutaraldehyde. The biosensor developed provides a reliable and inexpensive way for preliminary testing of common environmental pollutants with a single sensor in accordance with assumed toxic effect by the choice of appropriate substrate and measurement conditions. The bi-enzyme sensor makes it possible to determine substituted phenols and aromatic amines in the micromolar range of their concentrations and anticholinesterase pesticides with detection limits of 0.1 (Coumaphos) and 0.03 micromol l(-1) (Chloropyrifos-methyl).
authors.affiliation: Chemistry Faculty of Kazan State University, 18 Kremlevskaya Street, Kazan 420008, Russia.
authors.forename: E V
authors.initials: EV
authors.lastname: Suprun
authors.forename: H C
authors.initials: HC
authors.lastname: Budnikov
authors.forename: G A
authors.initials: GA
authors.lastname: Evtugyn
authors.forename: Kh Z
authors.initials: KhZ
authors.lastname: Brainina
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002091:Butyrylcholinesterase / Q000032:analysis / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002800:Cholinesterase Inhibitors / Q000032:analysis* / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D004800:Enzymes, Immobilized / Q000032:analysis / Q000737:chemistry; D019544:Equipment Failure Analysis; D006735:Horseradish Peroxidase / Q000032:analysis / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis* / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D014439:Tyramine / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D002800:Cholinesterase Inhibitors; D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D010575:Pesticides; D011108:Polymers; D014874:Water Pollutants, Chemical; D002244:Carbon; D006735:Horseradish Peroxidase; D002091:Butyrylcholinesterase; D014439:Tyramine