title: Biosensors for phenolic compounds by immobilization of tyrosinase in photocurable methacrylic-acrylic membranes of varying hydrophilicities.
abstract: Electrochemical biosensors for phenolic compound determination were developed by immobilization of tyrosinase enzyme in a series of methacrylic-acrylic based biosensor membranes deposited directly using a photocuring method. By modifying the hydrophilicity of the membranes using different proportions of 2-hydroxyethyl methacrylate (HEMA) and butyl acrylate (nBA), we developed biosensor membranes of different hydrophilic characters. The differences in hydrophilicity of these membranes led to changes in the sensitivity of the biosensors towards different phenolic compounds. In general biosensors constructed from the methacrylic-acrylic based membranes showed the poorest response to catechol relative to other phenolic compounds, which is in contrast to many other biosensors based on tyrosinase. The decrease in hydrophilicity of the membrane also allowed better selectivity towards chlorophenols. However, phenol biosensors constructed from the more hydrophilic membrane materials demonstrated better analytical performance towards phenol compared with those made from less hydrophilic ones. For the detection of phenols, these biosensors with different membranes gave detection limits of 0.13-0.25 microM and linear response range from 6.2-54.2 microM phenol. The phenol biosensors also showed good phenol recovery from landfill leachate samples (82-117%).
authors.affiliation: School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
authors.forename: Sharina Abu
authors.initials: SA
authors.lastname: Hanifah
authors.forename: Lee Yook
authors.initials: LY
authors.lastname: Heng
authors.forename: Musa
authors.initials: M
authors.lastname: Ahmad
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004563:Electrochemistry; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D010636:Phenols / Q000032:analysis*; D010777:Photochemistry; D015203:Reproducibility of Results; D013997:Time Factors; D014867:Water / Q000737:chemistry; D017155:Wettability
chemical_list: D000180:Acrylic Resins; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D010636:Phenols; D014867:Water; D014442:Monophenol Monooxygenase