Controlling DNA/Surface Interactions for Potential Pulse‐Assisted Preparation of Multi‐Probe DNA Microarrays

The possibility of selectively modifying microarray electrodes with different DNA sequences in a controlled way without the need for local positioning of solutions or local modification of array surfaces is demonstrated. Potential pulse sequences are employed to perform sequential surface modification of a 32‐gold‐electrode array with two different thiolated DNA capture sequences, surface passivation and regeneration of selected microarray electrodes, all by adjusting the potential intensities of the same potential pulse‐assisted method. We achieve reproducible and controlled DNA immobilization together with minimization of false signals originating from unspecific adsorption or undesired co‐immobilization. This methodology is not limited to DNA chips and it is potentially suitable for a wide range of applications employing Au−S chemistry. It can be employed in laboratory conditions for localizing different reactive chemistries onto predefined electrodes of an array without the need for complex and expensive apparatus and special conditions.