title: Label-free potentiometric biosensor based on solid-contact for determination of total phenols in honey and propolis.
abstract: We developed a label-free potentiometric biosensor using tyrosinase extracted from Musa acuminata and immobilized by covalent bond on a surface of a solid-contact transducer. The transducer was manufactured containing two layers. The first layer contained a blend of poly(vinyl) chloride carboxylated (PVC-COOH), graphite and potassium permanganate. On this layer, we deposited a second layer containing just a mixture of poly(vinyl chloride) carboxylated and graphite. On the last layer of the transducer, we immobilized the tyrosinase enzyme by reaction with N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride. The solid-contact potentiometric biosensor presented at low detection limit of 7.3×10-7M and a linear range to catechol concentration between 9.3×10-7M and 8.3×10-2M. This biosensor was applied to determine the amount of total phenols in different samples of honey and propolis. The results agreed with the Folin-Ciocalteu method.
authors.affiliation: The Municipal University of São Caetano do Sul 50, Santo Antônio Street, Postal Code: 09521-160 São Caetano do Sul - SP, Brazil.
authors.forename: Patrícia Ferrante
authors.initials: PF
authors.lastname: Draghi
authors.affiliation: The Municipal University of São Caetano do Sul 50, Santo Antônio Street, Postal Code: 09521-160 São Caetano do Sul - SP, Brazil. Electronic address: jcbastos@uscs.edu.br.
authors.forename: Julio Cesar Bastos
authors.initials: JCB
authors.lastname: Fernandes
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D006722:Honey / Q000032:analysis*; D007700:Kinetics; D055595:Mechanical Phenomena; D014442:Monophenol Monooxygenase / Q000378:metabolism; D028521:Musa / Q000201:enzymology; D010636:Phenols / Q000032:analysis*; D011199:Potentiometry; D011429:Propolis / Q000737:chemistry*
chemical_list: D010636:Phenols; D011429:Propolis; D014442:Monophenol Monooxygenase
keywords: Biosensor; Grand nain banana; Honey; Potentiometry; Total phenols; Tyrosinase