Electrochemical gene sensor arrays prepared using non-contact nanoliter array spotting of gene probes

A capillary-based pitch-variable array spotter, designed to dispense solutions in nanoliter volumes with high precision and density, was used to immobilize gene probes on a microelectrode array chip. Small volumes of the probe solutions were dispensed onto the microelectrodes, without any physical contact between the capillary ends and the electrode surfaces, to fabricate an electrochemical gene sensor array chip. The fabricated gene sensor array chip showed sequence-selective responses, expressed on a pseudocolor scale, to a target DNA sample. It was demonstrated that this dispensing technique provides integrated sensor array chips by dispensing small volumes of solutions of synthesized functional gene probes onto microelectrode array chips, a process not possible with conventional dispensing techniques.