Preparation and characterization of DNA films using oleylamine modified Au surfaces.

Thin films composed of oleylamine (OLA) and double-stranded deoxyribonucleic acid (dsDNA from Salmon testes) have been successfully constructed on polycrystalline Au surfaces using the electrostatic adsorption and self-assembly (SA) technique. The formation of the Au/OLA/dsDNA films was followed step-by-step by Quartz Crystal Microbalance with energy dissipation (QCM-D), Atomic Force Microscopy (AFM), and electrochemical techniques such as Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). The use of these techniques allowed the characterization and the follow up of the successful construction of the OLA/dsDNA composite film. The main advantages of the proposed methodology are the simplicity of the modification procedure, the stability of the dsDNA self-assembled film, and the potential employment of the dsDNA modified gold electrodes to study the interactions of DNA with target molecules.