title: An organically modified silicate-based ethanol biosensor.
abstract: A novel electrocatalytic ethanol biosensor using ferrocene-encapsulated palladium (Pd)-linked organically modified sol-gel glass (ormosil) is reported. The alkoxy precursors used to prepare the new ormosil-based electrocatalytic biosensor are Pd-linked glycidoxypropyltrimethoxysilane and trimethoxysilane. Pd-glycidoxypropyltrimethoxysilane (black solution) is made by mixing aqueous solutions of palladium chloride and glycidoxypropyltrimethoxysilane. The new ormosil is made using a Pd-linked silane precursor, trimethoxysilane, an aqueous solution of ferrocene monocarboxylic acid, and HCl. Alcohol dehydrogenase (ADH) is assembled over the ferrocene-ormosil layer using polyvinyl alcohol and then protecting the immobilized enzyme layer using Millipore filter membranes (pore size 1 microm). The electrocatalytic response of immobilized ADH, soluble nicotinamide adenine dinucleotide, and Pd-linked ormosil-encapsulated ferrocene is then observed. The electrocatalytic oxidation of NADH and the subsequent ADH-catalyzed formation of NADH are monitored electrochemically. Typical results recorded after the addition of varying concentrations of ethanol are reported; however, the sensor is sensitive to other alcohol and known ADH-sensitive substrates. The stability and reproducibility of the new ethanol biosensor are reported.
authors.affiliation: Department of Chemistry, Banaras Hindu University, Varanasi, 221005, India.
authors.forename: P C
authors.initials: PC
authors.lastname: Pandey
authors.forename: S
authors.initials: S
authors.lastname: Upadhyay
authors.forename: I
authors.initials: I
authors.lastname: Tiwari
authors.forename: V S
authors.initials: VS
authors.lastname: Tripathi
mesh_terms: D000426:Alcohol Dehydrogenase / Q000378:metabolism; D015374:Biosensing Techniques; D002138:Calibration; D004339:Drug Compounding; D004563:Electrochemistry; D004800:Enzymes, Immobilized / Q000378:metabolism; D000431:Ethanol / Q000032:analysis* / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism; D000075163:Metallocenes; D015394:Molecular Structure; D009243:NAD / Q000378:metabolism; D010165:Palladium; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012821:Silanes / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004800:Enzymes, Immobilized; D005296:Ferrous Compounds; D000075163:Metallocenes; D012821:Silanes; D009243:NAD; C032949:ferrocenecarboxylic acid; D000431:Ethanol; D010165:Palladium; D000426:Alcohol Dehydrogenase