title: A thionine-modified carbon paste amperometric biosensor for catechol and bisphenol A determination.
abstract: A thionine-modified carbon paste electrode for catechol and Bisphenol A (BPA) detection is presented. Graphite powder was modified by adsorbing thionine as electrochemical mediator. The electrochemical response of the modified carbon paste electrode (CPE) was determined before electrode modification with tyrosinase. Then, tyrosinase was added in order to assemble a biosensor. Once established the best operative conditions, an interelectrode reproducibility around 7% was obtained and the resulting biosensor showed improved sensitivities and (S=139.6+/-1.1 nA/microM for catechol and S=85.4+/-1.5 nA/microM for BPA) in comparison with the biosensor constructed without thionine (S=104.4+/-0.5 nA/microM for catechol and S=51.1+/-0.6 nA/microM for BPA) and low detection limits (0.15 microM for both the electrodes and analytes). Also the comparison with the results reported in the literature showed higher sensitivity and lower detection limit for our biosensor. Moreover the functioning of the thionine-tyrosinase CPE was validated following a biodegradation process of water polluted by BPA and comparing the time changes of BPA concentration inferred by the biosensor calibration curve and those determined by means of HPLC measurements.
authors.affiliation: Dipartimento di Medicina Sperimentale, Seconda Università di Napoli, Naples, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Portaccio
authors.forename: D
authors.initials: D
authors.lastname: Di Tuoro
authors.forename: F
authors.initials: F
authors.lastname: Arduini
authors.forename: M
authors.initials: M
authors.lastname: Lepore
authors.forename: D G
authors.initials: DG
authors.lastname: Mita
authors.forename: N
authors.initials: N
authors.lastname: Diano
authors.forename: L
authors.initials: L
authors.lastname: Mita
authors.forename: D
authors.initials: D
authors.lastname: Moscone
mesh_terms: D001559:Benzhydryl Compounds; D015374:Biosensing Techniques / Q000592:standards / Q000706:statistics & numerical data; D002244:Carbon; D002396:Catechols / Q000032:analysis*; D055664:Electrochemical Techniques; D052244:Endocrine Disruptors / Q000032:analysis; D004785:Environmental Pollutants / Q000032:analysis; D004968:Estrogens, Non-Steroidal / Q000032:analysis; D014442:Monophenol Monooxygenase; D010636:Phenols / Q000032:analysis*; D010640:Phenothiazines; D010968:Plasticizers / Q000032:analysis; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D002244:Carbon; D002396:Catechols; D052244:Endocrine Disruptors; D004785:Environmental Pollutants; D004968:Estrogens, Non-Steroidal; D014442:Monophenol Monooxygenase; D010636:Phenols; D010640:Phenothiazines; D010968:Plasticizers; C034221:catechol; C006780:bisphenol A; D000098826:Bisphenol A Compounds; C009469:thionine