title: An amperometric biosensor for fish freshness detection from xanthine oxidase immobilized in polypyrrole-polyvinylsulphonate film.
abstract: A new amperometric biosensor was developed for determining hypoxanthine in fish meat. Xanthine oxidase with pyrrole and polyvinylsulphonate was immobilized on the surface of a platinum electrode by electropolymerization. The determination of xanthine-hypoxanthine was performed by means of oxidation of uric acid liberated during the enzyme reaction on the surface of the enzyme electrode at + 0.30V (SCE). The effects of pH, substrate concentration, and temperature on the response of the xanthine-hypoxanthine biosensor were investigated. The linear working range of the enzyme electrode was 1.0 × 10(-7) -1.0 × 10(-3) M of the hypoxanthine concentration, and the detection limit was 1.0 × 10(-7)M. The apparent K(m(app)) and I(max) of the immobilized xanthine oxidase were found to be 0.0154 mM and 1.203 μA/mM, respectively. The best pH and temperature value for xanthine oxidase were selected as 7.75 and 25°C, respectively. The sensor was used for the determination of hypoxhantine in fish meat. Results show that the fish degraded very rapidly after seven days and the hypoxanthine amount was found to increase over days of storage.
authors.affiliation: Gazi University, Ankara, Turkey.
authors.forename: Nezaket
authors.initials: N
authors.lastname: Dolmaci
authors.forename: Servet
authors.initials: S
authors.lastname: Çete
authors.forename: Fatma
authors.initials: F
authors.lastname: Arslan
authors.forename: Ahmet
authors.initials: A
authors.lastname: Yaşar
mesh_terms: D000818:Animals; D055162:Biocatalysis; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D005399:Fishes; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D019271:Hypoxanthine / Q000032:analysis / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D015203:Reproducibility of Results; D013451:Sulfonic Acids / Q000737:chemistry*; D013696:Temperature; D014527:Uric Acid / Q000737:chemistry; D019820:Xanthine / Q000032:analysis / Q000737:chemistry; D014969:Xanthine Oxidase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004800:Enzymes, Immobilized; D011108:Polymers; D011145:Polyvinyls; D011758:Pyrroles; D013451:Sulfonic Acids; D019820:Xanthine; C008959:lyapolate; D014527:Uric Acid; D019271:Hypoxanthine; C067635:polypyrrole; D006861:Hydrogen Peroxide; D014969:Xanthine Oxidase; D008751:Methylene Blue