Novel Iron(III)−Induced Prooxidant Activity Measurement Using a Solid Protein Sensor in Comparison with a Copper(II)−Induced Assay

Biosensors for Antioxidants Detection: Trends and Perspectives

Herein we review the recent advances in biosensors for antioxidants detection underlying principles particularly emphasizing advantages along with limitations regarding the ability to discriminate between the specific antioxidant or total content. Recent advances in both direct detection of antioxidants, but also on indirect detection, measuring the induced damage on DNA-based biosensors are critically analysed. Additionally, latest developments on (bio)electronic tongues are also presented.

Evaluation of antioxidant activity of chlorogenic acids and coffee extracts by an electrochemical DNA-based biosensor

Sensitivity of dsDNA structure towards OH radicals as the pro-oxidants has been utilized as the detection principle of an analytical procedure applied for the first time to the evaluation of antioxidant activity (AOA) of 6 chlorogenic acids (CGAs) and extracts of 10 coffees. A nanostructured electrochemical DNA-based biosensor was prepared using a commercial electrode assembly and treated in the DNA cleavage agent formed by the Fenton type reaction. An addition of CGAs and aqueous coffee extracts significantly diminishes the degree of DNA degradation determined using cyclic voltammetry (CV) with the redox indicator [Fe(CN)6]3-/4-. The AOA decreases in order caffeic acid, CFA, >caffeoylquinic acids, CQAs, >dicaffeoylquinic acids, diCQAs, exhibiting the relative portion of survived DNA of about 71%, 70% and 69%, respectively, and of about 72% for C. robusta, Cherry, India (green bean) to 49% for Nescafé Espresso. Mechanisms of antioxidative properties are discussed.