Penentuan Keterulangan Biosensor Antioksidan dari Ekstrak Deinococcus radiodurans dan Perbandingan Metode Elektrokimia dengan Spektrofotometri

Abstract

Biosensor electrochemical method for antioxidant is an alternative method in measuring the capacity of antioxidant. This method has higher sensitivity, lower cost and simple instrumentation compare to spectrophotometry. The objective of this research was to optimize the activity of SOD extract of immobilized zeolite-Deinococcus radiodurans, repeatabillity, and the comparison of detection limit between electrochemical and spectrophotometry method. The optimum condition of SOD antioxidant activity of D. radiodurans extract was obtained at temperature of 31 °C, pH 9, and zeolites 137.5 mg. The optimum current obtained from the repeatibility was 1.749 μA with standard deviation of 0.01, and coefficient of variation of 0.59%. Detection limit of electrochemical biosensor was 1.76 ppm, while spectrophotometry has lower detection limit with value of 2.01 ppm. Electrochemical method can be used to detect lower concentrations analytes.