The Voltammetric Responses of High and Low Molecular Weight DNA on a Variety of Carbon Substrates; Demonstrating the Benefits of Graphitic Surfaces

This work compares the voltammetric response of high (∼2000 bp) and low (≤300 bp) molecular weight DNA on a variety of carbon based electrodes demonstrating for both species the advantages of using graphitic electrodes. Results suggest that the edge plane defects are kinetically dominant for the electro-oxidation of nucleobases, whereas the basal plane sites are favoured for adsorption of the DNA to the electrode surface. For the high molecular weight DNA it is shown that although larger currents are obtained through the use of the edge plane electrode, it is beneficial in terms of signal-to-noise ratio to use a basal plane electrode.