title: A naphthoquinone/SAM-mediated biosensor for olive oil polyphenol content.
abstract: We report on the design of an amperometric tyrosinase-based biosensor using a self-assembled monolayer of ω-mercaptopropyl naphthoquinone on gold electrode as an electron mediator. Under optimal conditions (i.e. pH=7.4 and E=-0.35V vs. KCl), the chronoamperometric response of the naphthoquinone-modified bioelectrode to successive additions of phenol was evaluated. The biosensor exhibits sensitive bioelectrocatalytic response at a working potential of -0.35V vs. Ag/AgCl (sat.KCl), reaching the steady-state current within 40s after each addition of phenol solution with a range of 0-135μM and a limit of detection and quantification which are 0.019μM and 0.0633μM, respectively. The bioelectrode was used to determine the content in polyphenol in a local virgin olive oil.
authors.affiliation: Université de Tunis El-Manar, Faculté des Sciences de Tunis, Département de Chimie, Laboratoire de Chimie Analytique & Electrochimie (LR99ES15), campus universitaire de Tunis El Manar, 2092 Tunis El-Manar, Tunisia.
authors.forename: Asma
authors.initials: A
authors.lastname: Hammami
authors.affiliation: Polymer Institute, Slovak Academy of Sciences, Dúbravskácesta 9, 845 41 Bratislava, Slovakia.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Kuliček
authors.affiliation: Université de Tunis El-Manar, Faculté des Sciences de Tunis, Département de Chimie, Laboratoire de Chimie Analytique & Electrochimie (LR99ES15), campus universitaire de Tunis El Manar, 2092 Tunis El-Manar, Tunisia. Electronic address: n.raouafi@fst.rnu.tn.
authors.forename: Noureddine
authors.initials: N
authors.lastname: Raouafi
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006046:Gold; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D009285:Naphthoquinones / Q000737:chemistry*; D000069463:Olive Oil / Q000737:chemistry* / Q000592:standards; D059808:Polyphenols / Q000032:analysis*
chemical_list: D004800:Enzymes, Immobilized; D009285:Naphthoquinones; D000069463:Olive Oil; D059808:Polyphenols; D006046:Gold; D014442:Monophenol Monooxygenase
keywords: Chronoamperometry; Electroactive monolayer; Impedance spectroscopy; Naphthoquinone; Phenol; Tyrosinase; Virgin olive oil