Accuracy of determination of mass of DNA films on gold electrodes

Mass and organization of layers of unmodified DNA strands of various lengths deposited from solutions of its various concentrations on the surface of a gold electrode were examined using EQCM, UV–vis and AFM. The accuracy of mass determination is vital for the electrochemical examination of interactions between DNA and ligands, especially drug molecules. For such studies, the parallel orientation of the DNA fragments/strands vs. electrode surface may be advantageous. We have found that the Sauerbrey equation can give satisfactory results for the mass of accumulated oligonucleotides if the deposition process is done under appropriate conditions. Apparently, the viscoelastic effect did not lead to substantial errors.