title: Amperometric phenol biosensor based on horseradish peroxidase entrapped PVF and PPy composite film coated GC electrode.
abstract: Polyvinylferrocene (PVF) was used as a mediator for the fabrication of a horseradish peroxidase (HRP)-modified electrode to detect phenol derivatives via a composite polymeric matrix of conducting polypyrrole (PPy). Through an electropolymerization process, enzyme HRP was entrapped with PPy in a three-electrode system onto a glassy carbon electrode previously covered with PVF, resulting in a composite polymeric matrix. Steady-state amperometric measurements were performed at -200 mV vs. Ag/AgCl in aqueous phosphate buffer containing NaCl 0.1 M (pH 6.8) in the presence of hydrogen peroxide. The response of the HRP-modified PVF electrode was investigated for various phenol derivatives, which were 4-chlorophenol, phenol, catechol, hydroquinone, 2-aminophenol, pyrogallol, m-cresol, and 4-methoxyphenol. Analytical parameters for the fabricated PVF electrode were obtained from the calibration curves. The highest sensitivity was obtained from the calibration of 4-chlorophenol as 29.91 nA/microM. The lowest detection limit was found to be 0.22 microM (S/N = 3) for catechol, and the highest detection limit was found to be 0.79 microM (S/N = 3) for 4-methoxyphenol among the tested derivatives. The biosensor can reach 95% of steady-state current in about 5 min. The electrode is stable for 2 months at 4 degrees Celsius.
authors.affiliation: Department of Environmental Engineering, Gebze Institute of Technology, 41400 Gebze, Turkey.
authors.forename: Meral
authors.initials: M
authors.lastname: Topcu Sulak
authors.forename: Elif
authors.initials: E
authors.lastname: Erhan
authors.forename: Bülent
authors.initials: B
authors.lastname: Keskinler
mesh_terms: D055162:Biocatalysis; D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005296:Ferrous Compounds / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008752:Methylene Chloride / Q000737:chemistry; D019800:Phenol / Q000032:analysis*; D011108:Polymers / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D005296:Ferrous Compounds; D011108:Polymers; D011145:Polyvinyls; D011758:Pyrroles; C451099:polyvinylferrocenium; D014867:Water; C067635:polypyrrole; D019800:Phenol; D008752:Methylene Chloride; D002244:Carbon; D006735:Horseradish Peroxidase