Application of cobalt oxide nanostructured modified aluminium electrode for electrocatalytic oxidation of guanine and single-strand DNA

A novel electrochemical biosensor for the selective and sensitive determination of guanine and single-strand DNA (ssDNA) has been developed by the electrodeposition of cobalt oxide nanoflowers (CoOx) on an aluminium electrode (Al). The modified aluminium electrode showed an excellent intensification of the guanine oxidation response in ssDNA. The morphological characteristics, phase composition and electrochemical properties of the modified electrode were studied by SEM, XRD and electrochemical impedance studies. The effects of scan rate, pH, and concentration of ssDNA and guanine on the response of the sensor were investigated. Detection limits of 4 and 450 nM were obtained for guanine and ssDNA, respectively. Simplicity of fabrication, excellent electrocatalytic ability, high stability and selectivity of the modified electrode were achieved.