Development of a new biosensor for superoxide radicals.
A superoxide dismutase (SOD) biosensor for determination of superoxide radicals has been developed by immobilization of superoxide dismutase within gelatin (G) on a Pt electrode surface. The properties of the biosensor have been investigated and optimum conditions-enzyme concentration, glutaraldehyde concentration, and pH-were determined. The response of the G-SOD biosensor was proportional to O2*- concentration and the detection limit was 0.01 mmol L(-1) at a signal-to-noise ratio of 3. The biosensor retained 89% and 60% of its sensitivity after use for three and four weeks, respectively. Immobilization of SOD on gelatin provides a biocompatible microenvironment around the enzyme and stabilizes the activity of the enzyme very efficiently. The superoxide dismutase biosensor was used to determine the antioxidant properties of acetylsalicylic acid-based drugs and the anti-radical activity of healthy and cancerous human brain tissues.
Emregül
Emel
E
Department of Chemistry, Faculty of Science, Ankara University, 06100 Ankara, Turkey. eemregul@yahoo.com
D001205:Ascorbic Acid / Q000737:chemistry; D001241:Aspirin / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004563:Electrochemistry; D004867:Equipment Design; D016166:Free Radical Scavengers / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D012680:Sensitivity and Specificity; D013482:Superoxide Dismutase / Q000737:chemistry*; D013481:Superoxides / Q000032:analysis* / Q000737:chemistry; D013997:Time Factors
D003432:Cross-Linking Reagents; D016166:Free Radical Scavengers; D013481:Superoxides; D013482:Superoxide Dismutase; D001205:Ascorbic Acid; D001241:Aspirin