Highly Sensitive Electrochemical Sensor for the Determination of 8-Hydroxy-2′-deoxyguanosine Incorporating SWCNTs-Nafion Composite Film

Abstract

8-Hydroxy-2′-deoxyguanosine (8-OHdG) is a typical biomarker of oxidative DNA damage and has attracted much attention in recent years since the level of 8-OHdG in body fluids is typically associated with various diseases. In this work, a simple and highly sensitive electrochemical sensor for the determination of 8-OHdG was fabricated incorporating single wall carbon nanotubes- (SWCNTs-) Nafion composite film coated on glassy carbon electrode. Nafion was chosen as an optimal adhesive agent from a series of adhesive agents and acted as a binder, enrichment, and exclusion film. Due to the strong cation-exchange ability of Nafion and the outstanding electronic properties of SWCNTs, the prepared SWCNTs-Nafion film can strongly enhance the electrochemical response to oxidation of 8-OHdG and efficiently alleviate the interferences from uric acid and ascorbic acid. The oxidation peak currents are linear with the concentration of 8-OHdG in the range of 0.03 to 1.25 μM with a detection limit of 8.0 nM (S/N = 3). This work demonstrates that SWCNTs-Nafion film can improve the sensitivity, selectivity, reproducibility, and stability, making it an ideal candidate for electrochemical detection of 8-OHdG.

Controlling parameters and characteristics of electrochemical biosensors for enhanced detection of 8-hydroxy-2′-deoxyguanosine

“…5a). This limit is one hundred times less than ELISA test and better than other reported biosensors (Table S1) 22–24,26,27,41–45 . Our immunosensor shows linear range 3 pM to 17.6 nM and the limit of detection was found to be 0.3 pM (100 fg/mL).…”

“…Most of them just describe how modifying the WE with nanostructures for improving sensitivity and limit of detection. Carbon nanotubes 22–25 , and graphene 24,26,27 have been commonly reported as good WE for the detection of 8-OHdG. Despite their higher conductivity and specificity, biosensors built with these materials showed sensitivity in the picomolar range.…”

8-hydroxy-2′-deoxyguanosine (8-OHdG) biomarker detection down to picoMolar level on a plastic antibody film

“…Such devices establish a direct reading of 8-OHdG, making use of its active redox properties on glassy carbon (Gutiérrez et al, 2016) (Jia et al, 2015)(L. Jia et al, 2013)(L. Yang et al, 2015) or pyrolytic graphitic (Gupta et al, 2016) supports, modified with highly conductive nanomaterials of multi-wall carbon nanotubes or graphene. In general, the detection capability of these devices varies from 1.1 to 97 nM, but some methods have shown severe interference from urine elements (mostly uric acid), solved therein by the addition of specific enzyme prior to the analysis stage.…”

Advancements in 2D Materials Based Biosensors for Oxidative Stress Biomarkers

“…Single wall carbon nanotubes-Nafion composite film modified electrode was able to detect this analyte in nanomolar concentrations. 116 Gupta et al used square wave voltammetry for the electrochemical detection of this analytical on a pyrolytic graphite electrode, which had a limit of detection in nanomolar range. 117 Hemin/G-quadruplex on the carbon nitride nanosheets were used for the electrochiluminescent detection of 8-OHdG in atomolar concentrations by Lv et al 118 More examples for the use of 2D layered material based sensors for this analyte are given in Table 2.…”