SENSING ASCORBIC ACID WITH DNA/PRUSSIAN BLUE CARBON PASTE ELECTRODE

A simple sensor for the detection of ascorbic acid (AA) was developed. The electrochemical behaviors were studied after successfully constructing through DNA electro-deposition on carbon paste electrode using Prussian blue (PB). The electrodes were characterized by Raman spectroscopy that confirmed electro-deposition of PB, functioning as a redox mediator. The detection method was based on DNA damage induced by hydroxyl radical generated by Fenton reaction in which ascorbic acid effectively scavenges the hydroxyl radical. The amount of DNA damage is proportional to the amount of ascorbic acid concentration which was analyzed by cyclic voltametry (CV). Obtained results show that DNA-based biosensor can be utilized for estimating ascorbic acid in vitamin-c tablets. The detection range of this biosensor was in the range of 1.14 µM to 12.54 µM. Interference effects and stability of the biosensor were also investigated, results show that the biosensor has high sensitivity and selectivity towards ascorbic acid concentrations.