Electrochemical evaluation of total antioxidant capacity of beverages using a purine-biosensor

Abstract

In this paper, it was evaluated the total antioxidant capacity (TAC) of beverages using an electrochemical biosensor. The biosensor consisted on the purine base (guanine or adenine) electro-immobilization on a glassy carbon electrode surface (GCE). Purine base damage was induced by the hydroxyl radical gener-ated by Fenton-type reaction. Five antioxidants were applied to counteract the deleterious effects of the hydroxyl radical. The antioxidants used were ascorbic acid, gallic acid, caffeic acid, coumaric acid and resveratrol. These antioxidants have the ability to scavenger the hydroxyl radical and protect the guanine and adenine immobilized on the GCE surface. The interaction carried out between the purine-base immobilized and the free radical in the absence and presence of antioxidants was evaluated by means of changes in the guanine and adenine anodic peak obtained by square wave voltammetry (SWV). The results demonstrated that the purine-biosensors are suitable for rapid assessment of TAC in beverages.

Square‐Wave Voltammetry: A Review on the Recent Progress

“…Recently, the detection of antibiotic certiofur has been achieved by applying square-wave voltammetry directly in milk samples following the hydrolysis of certiofur [144]. Owing to its performances for determination of various polyphenolic antioxidants, useful and cheap SW voltammetric methods have been developed for the determination of the total antioxidative capacity in food products such as edible oils [145] and beverages [146]. Alkaloids are other class of natural compounds that attract considerable interest due to their wide range of applications in the pharmaceutical industry.…”

Antioxidant Capacity in Vanilla Extracts Obtained by Applying Focused Microwaves

“…Although Trolox is the most used reagent by ORAC method due to its high sensibility, caffeic acid has been also used because it has a high antioxidant power [36]. So, in this paper all results have been expressed as mg caffeic acid/g of vanilla bean.…”

Novel Spectroscopic and Electrochemical Sensors and Nanoprobes for the Characterization of Food and Biological Antioxidants

“…In a similar study, a purine biosensor was used to estimate the TAC of beverages with SWV. In the study, adenine or guanine was electrochemically immobilized on GCE (i.e., an adsorptive accumulation step was used) and the resulting peak current due to the oxidation of nucleic bases was measured [ 41 ]. Mello et al manufactured a DNA-electrochemical biosensor for investigating antioxidative properties of different plant materials by immobilizing a dsDNA layer on a screen printed electrode and using a Fenton reaction to oxidize DNA.…”