Biosensor antioksidan berbasis superoksida dismutase deinoccus radiodurans diimobilisasi pada nanokomposit zeolit alam indonesia

Abstract

The immobilization superoxide dismutase extract from D. radioduras on a zeolite nanocomposite modified electrode were studied. Cyclic voltammetry (CV) are employed to investigate the catalytic behavior of the biosensor. The superoxide radical was produced in solution using the xantine/xanthine oksidase system. Antioxidant activity vitamin C was determined by 2, 2-diphenil-2-picrylhydrazyl (DPPH) free radical scavenging method and comparing with biosensor SOD. Optimum conditions for SOD activity was at pH 9, temperature 300 C, zeolite 137.5mg, and SOD 3 U/ml for pure SOD and 9, temperature 300 C, zeolite 137.5mg, and SOD 1500μg/mL for D. radiodurans SOD. Dismutation reaction kinetics of superoxide catalyzed by SOD followed the Lineweaver-Burk kinetics with D. radiodurans SOD Kmapp value was higher than pure SOD. Antioxidant capacity for Vitamin C was 19.49 ppm using DPPH method and value 0,7 for relative antioxidant capacity using biosensor SOD. In conclusion, D radiodurans SOD immobilized on a zeolite nanocomposite had a great potential as biological recognition component for antioxidant biosensor.