title: Preparation and optimization of a bienzymic biosensor based on self-assembled monolayer modified gold electrode for alcohol and glucose detection.
abstract: The aim of this project was to develop a bienzymic biosensor, which was based on co-immobilization of alcohol oxidase and glucose oxidase on the same electrode by formation of self-assembled monolayer (SAM) for selective determination of ethanol and glucose. In the biosensor construction the enzymes and the mediator, tetrathiafulvalene (TTF), were immobilized with cross-linking agents glutaraldehyde and cysteamine by forming a self-assembled monolayer (SAM) on a gold disc electrode. Amounts of ethanol and glucose were amperometrically detected by monitoring current values at reduction potential of TTF(+), 0.1V. Decreases in biosensor responses were linearly related to glucose concentrations between 0.1 and 1.0 mM and ethanol concentrations between 1.0 and 10 mM. Limits of detection of the biosensor for ethanol and glucose were calculated to be 0.75 and 0.03 mM, respectively. In the optimization studies of the biosensor some parameters such as optimum pH, optimum temperature, enzyme amount, effect of TTF concentration and duration of SAM formation were investigated.
authors.affiliation: Department of Biochemistry, Faculty of Science, Ege University, Izmir, Turkey.
authors.forename: Engin
authors.initials: E
authors.lastname: Asav
authors.forename: Erol
authors.initials: E
authors.lastname: Akyilmaz
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D000431:Ethanol / Q000032:analysis* / Q000737:chemistry; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D020099:Coated Materials, Biocompatible; D000431:Ethanol; D006046:Gold; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D005949:Glucose Oxidase; D005947:Glucose