CHED 294 |
| Rotating disk enzyme electrode (RDEE) is an electrochemical biosensor consisting of a membrane covered electrode with a platinum (Pt) disk modified by layers of enzyme on the end of an insulated cylindrical shaft. The controlled rotation of the electrode provides continuous stirring of the sample solution and promotes the diffusion of the redox active species to the electrode surface. RDEE modified with xanthine oxidase (XOx) was constructed for the amperometric detection of xanthine, a purine found in human blood, urine, and muscle tissue. XOx in the presence of oxygen catalyzes the oxidation of xanthine to uric acid and produces hydrogen peroxide (H2O2). The oxidation of H2O2 at the Pt electrode surface was detected at the optimized potential of 0.65 V vs. Ag wire pseudo reference electrode. Amperometrically monitoring the analyte concentrations using an enzyme electrode has advantages such as ease of detection, reusability, lower cost, and shorter analysis times. The detection potential, pH, temperature, and electrode rotation rate were optimized and the limits of detection determined. |
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Undergraduate Research Poster Session: Analytical Chemistry
11:00 AM-1:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |