Evaluation of the total antioxidant capacity of flavored water and electrochemical purine damage by sulfate radicals using a purine-based sensor

摘要

In this study, a method for the electrochemical quantification of the total antioxidant capacity (TAC) inbeverages was developed. The method is based on the oxidative damage to the purine bases, adenineor guanine, that are immobilized on a glassy carbon electrode (GCE) surface. The oxidative lesions onthe DNA bases were promoted by the sulfate radical generated by the persulfate/iron(II) system. Thepresence of antioxidants on the reactive system promoted the protection of the DNA bases immobilizedon the GCE by scavenging the sulfate radical. Square-wave voltammetry (SWV) was the electrochemicaltechnique used to perform this study. The efficiencies of five antioxidants (ascorbic acid, gallic acid,caffeic acid, coumaric acid and resveratrol) in scavenging the sulfate radical and, therefore, their abilityto protect the purine bases immobilized on the GCE were investigated. These results demonstrated thatthe purine-based biosensor is suitable for the rapid assessment of the TAC in flavors and flavored water.