DNA-based sensor against nitrite oxide radical: Evaluation of total antioxidant capacity in beverages

•A DNA-based sensor was developed for the TAC quantification in beverages.•RNOS was used to induce lesions onto DNA-based material.•Ascorbic acid has the ability to scavenge RNOS and protect DNA.•TAC was measured through sensor and conventional methods.•The DNA-based sensor is suitable for TAC determination in food juice matrices.

Reactive nitrogen and oxygen species are produced in cells and play an important role in the oxidative metabolism; when in abnormal concentrations, they are able to induce oxidative damage on biomolecules, namely in DNA. In this paper it is described, an electrochemical DNA-based sensor against NO radical developed for total antioxidant capacity (TAC) evaluation. The sensor consisted on dA20 (adenine-rich oligonucleotide) physically adsorbed into carbon paste electrode (CPE). When this dA20-CPE was damaged, by immersion in a freshly generated NO radical, a protective effect onto dA20 was observed in the presence of antioxidants (ascorbic, gallic, caffeic, p-coumaric acids). Electrochemical studies were performed through square wave voltammetry. The construction of the sensor is simple, fast and the results indicated that the DNA-based sensor is suitable, accurate, and can be used to the assessment of TAC in commercial samples of juices.