Abstract

The immobilisation of DNA probe on gold electrode surface with the optimal concentration is very important to develop of the DNA biosensors. In this study, we conducted an experiment that determined the optimal concentration of the probe attached the electrodes for the maximum hybridization efficiency. We have used a method that control the surface density of DNA probe by annealing probe modified by thiol and mercaptohexanol. Based on the linear relationship between the mol ratio and density probe, we control probe concentration in the sensor fabricating process as well as the molecular density of DNA probes on the electrode surface. The result of probe concentration 500 nM is optimal for hybidization with DNA target.