Electrochemical DNA Sensor Based on Carbon Black—Poly(Neutral Red) Composite for Detection of Oxidative DNA Damage

Abstract

Voltammetric DNA sensor has been proposed on the platform of glassy carbon electrode covered with carbon black with adsorbed pillar[5]arene molecules. Electropolymerization of Neutral Red performed in the presence of native or oxidatively damaged DNA resulted in formation of hybrid material which activity depended on the DNA conditions. The assembling of the surface layer was confirmed by scanning electron microscopy and electrochemical impedance spectroscopy. The influence of DNA and pillar[5]arene on redox activity of polymeric dye was investigated and a significant increase of the peak currents was found for DNA damaged by reactive oxygen species generated by Cu2+/H2O2 mixture. Pillar[5]arene improves the electron exchange conditions and increases the response and its reproducibility. The applicability of the DNA sensor developed was shown on the example of ascorbic acid as antioxidant. It decreases the current in the concentration range from 1.0 μM to 1.0 mM. The possibility to detect antioxidant activity was qualitatively confirmed by testing tera infusion. The DNA sensor developed can find application in testing of carcinogenic species and searching for new antitumor drugs.

Label-Free Bioelectrochemical Methods for Evaluation of Anticancer Drug Effects at a Molecular Level

“…Some other compounds (such as mitomycin C) form covalent bonds with nucleic acid bases to create adducts. Synthetic oligonucleotides, genomic DNA [69,76], or stem loop structures [77] can be used to assess the alterations induced by the molecule on DNA. Altered structural, chemical, and physicochemical properties of DNA are reflected in its behavior at the electrochemical transducer, since the binding of drug molecules to DNA causes a change in the intrinsic electrochemical signal of the DNA, i.e., adenine and guanine redox signals ( Figure 5).…”

Electrochemical DNA Sensor Based on the Copolymer of Proflavine and Azure B for Doxorubicin Determination

“…Polyelectrolyte complexes of the redox active polymers and DNA have been successfully applied for the detection of specific biochemical interactions of the DNA influencing redox equilibria of the support [3]. For this purpose, polyaniline [42], poly(Neutral red) [27,43], poly(Methylene blue) [43], poly(Methylene Green) [43], poly(Azure B) [29], and poly(proflavine) [31] have been used. In this work, the DNA solution was applied on the working surface of the electrode covered with the copolymer and either dried or left capped with plastic tube preventing drying for a certain time.…”

“…Methylene blue has found a broad application as a redox probe and diffusionally-free indicator in DNAand aptasensors [24,25]. Neutral red was also implemented in the biosensor assembly for mediation of the electron transfer [26][27][28]. Although they show satisfactory characteristics of the electron transfer, their application can be limited by some drawbacks, e.g., very high non-specific adsorption of the Methylene blue and low selectivity of mediation by the Neutral red.…”

Electrochemical Sensor Based on Poly(Azure B)-DNA Composite for Doxorubicin Determination

“…To some extent, drawbacks of polyaniline as the DNA support in the biosensor assembly can be overcome by the application of other polymerizable compounds with intrinsic redox activity, e.g., thiazine and phenazine dyes (Methylene blue [29], Methylene green [30], and Neutral red [31,32]). However, changes in their redox activity caused by DNA interactions are mostly insufficient for detection of small drug molecules.…”

“…However, changes in their redox activity caused by DNA interactions are mostly insufficient for detection of small drug molecules. Meanwhile, DNA sensors based on redox active dyes were successfully used for the detection of oxidative DNA damage and aptamer-analyte interactions by shifts of the peak currents and potentials, as well as by changes in the electrochemical impedance parameters [29,30,31,32].…”