title: Preliminary investigations on a new disposable potentiometric biosensor for uric acid.
abstract: In this paper, uricase, catalase, and electron mediator were coimmobilized on the surface of the tin oxide (SnO2)/indium tin oxide (ITO) glass, to develop a disposable potentiometric uric acid biosensor. The SnO2/ITO glass was employed as a pH sensor, fabricated by sputtering SnO2 thin films on the ITO glass. 3-Glycidyloxypropyltrimethoxysilane (GPTS) was utilized to immobilize uricase, catalase and the electron mediator (ferrocenecarboxylic acid, FcA) on the sensing window. The experimental results reveal that the optimal weight ratio of uricase, FcA to catalase (CAT) is 4:1:2. The sensor responds linearly between 2 mg/dl and 7 mg/dl at pH 7.5, in 20 mM of test solution, with a correlation coefficient of 0.99213. Accordingly, no significant interference was observed when interfering substances, glucose, urea and ascorbic acid, were added to the uric acid solution. Moreover, the recorded voltage was relatively constant during the first 28 days of measurement. Consequently, a potentiometric uric acid biosensor was realized with the advantages of low cost and simple fabrication.
authors.affiliation: Institute of Biomedical Engineering, Chung Yuan Christian University, Taiwan 320, ROC. wei20208@tipo.gov.tw
authors.forename: Cheng Wei
authors.initials: CW
authors.lastname: Liao
authors.forename: Jung Chuan
authors.initials: JC
authors.lastname: Chou
authors.forename: Tai Ping
authors.initials: TP
authors.lastname: Sun
authors.forename: Shen Kan
authors.initials: SK
authors.lastname: Hsiung
authors.forename: Jui Hsiang
authors.initials: JH
authors.lastname: Hsieh
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006863:Hydrogen-Ion Concentration; D008839:Microelectrodes; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014503:Urate Oxidase / Q000032:analysis / Q000737:chemistry*; D014527:Uric Acid / Q000652:urine*; D016482:Urinalysis / Q000295:instrumentation* / Q000379:methods
chemical_list: D014527:Uric Acid; D014503:Urate Oxidase