Development of disposable superoxide dismutase biosensor to determined the antioxidant capacity in tea plant

Abstract

A disposable enzymatic biosensor has been developed using superoxide dismutase (SOD) enzyme as its sensing material for the determination of antioxidant capacity of tea samples. The SOD was physically immobilized in a gel called Kappa-carrageenan membrane which suitable for enzyme entrapment. The usefulness of the biosensor for the food analysis was demonstrated by determining the percentage of inhibition of tea samples by using cyclic voltametric method with DropSens Electrochemical cells instrument and compared to the standard method, UV-VIS Spectrophotometry. Design of disposable electrode was suggested to be fabricated by using polyvinyl chloride (PVC). The antioxidant capacity of tea sample can be determined by disposable superoxide dismutase biosensor by the comparison with DPPH reaction by spectrophotometry. Qualitatively, the antioxidants in tea samples show the good results by oxidation and reduction curve of cyclic voltamogram. Quantitatively, the inhibition percentage of antioxidants shows by standard spectrophotometry method were 28.15 %, 34.99 %, 70.03 %, 85.97 % and 90.01 %, when the concentration of tea sample increases. While for biosensor were 10.68 %, 21.72 %, 30.92 %, 41.46 % and 49.45 %.