DNA-based biosensors with external Nafion and chitosan membranes for the evaluation of the antioxidant activity of beer, coffee, and tea

Abstract

Novel electrochemical DNA-based biosensors with outer-sphere Nafion and chitosan protective membranes were prepared for the evaluation of antioxidant properties of beverages (beer, coffee, and black tea) against prooxidant hydroxyl radicals. A carbon working electrode of a screen-printed three-electrode assembly was modified using a layer-by-layer deposition technique with low molecular weight double-stranded DNA and a Nafion or chitosan film. The membrane-covered DNA biosensors were initially tested with respect to their voltammetric and impedimetric response after the incubation of the beverage and the medium exchange for the solution of the redox indicator [Fe(CN)6]3−/4−. While the Nafion-protected biosensor proved to be suitable for beer and black tea extracts, the chitosan-protected biosensor was successfully used in a coffee extract. Afterwards, the applicability was successfully verified for these biosensors for the detection of a deep degradation of the surface-attached DNA at the incubation in the cleavage agent (hydroxyl radicals generated via Fenton reaction) and for the evaluation of antioxidant properties of coffee and black tea extracts against prooxidant hydroxyl radicals. The investigation of the novel biosensors with a protective membrane represents a significant contribution to the field of electrochemical DNA biosensors utilization.

Voltammetric Detection of Oxidative DNA Damage Based on Interactions between Polymeric Dyes and DNA

“…First, voltammetric detection of the signals of the guanine oxidation on the electrodes covered with adsorbed DNA should be mentioned. The appropriate peaks on voltammograms are commonly observed at high anodic potential on carbonaceous materials . Conformational changes of the damaged DNA increase the accessibility of guanine residues for anodic oxidation and hence the appropriate currents recorded with direct current or square wave voltammetry.…”

Application of promising carbonaceous materials in electrochemical DNA sensing

“…Variations in the conditions of the manufacturing process of activated carbons allow the generation of numerous types of them which differ in their basic features like surface area, porosity, surface chemistry etc. Thus, with activation, its properties can be easily changed to have large internal as well as specific surface area and porosity, high density of carbon in graphite-like layers, resulting in high mechanical strength [16]. Activated carbon-based systems can remove a large variety of pollutants from the solution phase with great efficiency [17].…”

“…Activated carbon-based systems can remove a large variety of pollutants from the solution phase with great efficiency [17]. To further develop highly efficient materials for various applications like adsorption or electrochemical sensors, modification of activated carbon [18] has received considerable attention. Among them, metal ion-loaded carbons show great application potential [18].…”

“…To further develop highly efficient materials for various applications like adsorption or electrochemical sensors, modification of activated carbon [18] has received considerable attention. Among them, metal ion-loaded carbons show great application potential [18]. The metals such as Ag incorporated to the surface act not only as active sites for selective adsorption of sulfur-containing aromatic compounds but also as structural stabilizers of the carbon materials and as catalyst initiators in reactive adsorption.…”

“…Based on their excellent electronic properties, antifouling properties, and ability to promote electron transfer reactions graphitic carbon materials also find interesting applications in biosensing devices. In addition, due to their bioselectivity for redox enzymes, these materials have been proven to be very useful for the quantification of organic substances such as glucose [13], proteins [14], hydroquinone [15] as well as antioxidant activity [16,17]. Activated carbonis, a black, solid, biocompatible carbonaceous material is commonly obtained from various organic precursors such as peat, wood, bituminous coal, coconut shells, petroleum pitch, polymers etc.…”