Electrochemical DNA-sensor for evaluation of total antioxidant capacity of flavours and flavoured waters using superoxide radical damage

摘要

In this paper, a biosensor based on a glassy carbon electrode (GCE) was used for the evaluation of the totalantioxidant capacity (TAC) of flavours and flavoured waters. This biosensor was constructed by immobilisingpurine bases, guanine and adenine, on a GCE. Square wave voltammetry (SWV) was selected forthe development of this methodology. Damage caused by the reactive oxygen species (ROS), superoxideradical (O2·−), generated by the xanthine/xanthine oxidase (XOD) system on the DNA-biosensor wasevaluated. DNA-biosensor encountered with oxidative lesion when it was in contact with the O2·−. Therewas less oxidative damage when reactive antioxidants were added. The antioxidants used in this workwere ascorbic acid, gallic acid, caffeic acid, coumaric acid and resveratrol. These antioxidants are capableof scavenging the superoxide radical and therefore protect the purine bases immobilized on the GCEsurface. The results demonstrated that the DNA-based biosensor is suitable for the rapid assess of TAC inbeverages.