Catalytic square-wave voltammetric detection of DNA with reversible metallopolymer-coated electrodes

Pyrolytic graphite electrodes with adsorbed poly(4-vinylpyridine) (PVP) with attached Ru(bpy)₂²⁺ gave reversible voltammetry, facilitating reusable DNA sensors. These electrodes gave catalytic voltammetric responses to poly(guanylic) acid and DNA at about 0.75 V vs SCE caused by catalytic oxidation of guanine moieties in these polynucleotides. ss-DNA gave twice the square-wave voltammetric catalytic current compared to an equivalent amount of ds-DNA, suggesting that the [Ru(bpy)₂-PVP]²⁺ polymer may be useful for detection of DNA hybridization and damage.