Preparation of nanostructured thin-film interfaces applicable in biosensors

Gold nanostructured thin-film electrodes (250 nm) were formed by using radio frequency (RF) diode sputtering, bias sputtering and ion etching. Biosensors based on the deoxyribonucleic acid (DNA) film immobilized at the gold surface were prepared by double-stranded DNA (dsDNA) adsorption. The behaviour of the DNA layer was investigated by using differential pulse voltammetry (DPV) with the DNA marker Co[(phen)3]3+ and cyclic voltammetry (CV) with the K3[Fe(CN)6] indicator and DNA-Co[(phen)3]3+ dissociation rate constant (k). The best result of attachment DNA binding were obtained in case of both sputtered sample only and the sample which was etched for 10 min at 150 °C.