Background:
8-Hydroxy-2’-deoxyguanosine (8-OHdG) has been regarded as a typical stable
biomarker of DNA oxidative damage, and its level is one of the criteria for early diagnosis of various
diseases. Considering the significance of 8-OhdG, various analytical techniques have been used for
assaying 8-OHdG but all of them suffer from basic limitations like highly expensive instrumentation,
large amount of sample requirement, complicated sample pre-treatment, tedious and time-consuming
procedures etc. However, electroanalytical sensors provide a faster, easy and sensitive means of
analyzing.
Methods:
The chitosan (CS) film provided the high electrode activity and stability which is required for
detecting 8-OHdG though direct electrochemical oxidation. Zirconia was employed because it has some
unique properties, such as high redox activity and selectivity etc. High-performance composite was
easily detected by differential pulse voltammetry at a working voltage of 0. 51 V (vs. Ag/AgCl). A rapid
and sensitive electrochemical sensor based on CS and metal oxide nanocrystalline for the determination
of 8-OHdG was established.
Results:
Under optimized experimental conditions, the peak currents of differential pulse voltammetry
increased as the concentrations of 8-OHdG increased from 10 to 200 ng·mL-1. The detection limit was
3.67 ng·mL-1 which was calculated by the S/N ratio of 3. The recoveries of the real spiked samples are
in the range between 93.2 to 105.3%.
Conclusion:
The electrochemical sensor for direct 8-OHdG determination using a new CS/zirconia
composite for GCE modification was developed and showed excellent reproducibility, stability and
sensitivity for the specific determination of 8-OHdG in real urine specimen.