We report an electrochemical DNA microarray sensor whose function is controlled with just two wires regardless of the number of individual sensing electrodes. The bipolar sensing electrode is modified with probe DNA, and the anode end of each electrode is configured to emit light (electrogenerated chemiluminescence) upon hybridization of cDNA labeled with electrocatalytic (oxygen reduction) Pt nanoparticles at the cathode. The important finding is that DNA can be selectively detected at an array of three electrodes. In principle, however, this advance provides a means for controlling the potential of many electrodes using just two wires and then indirectly determining the current flowing through all of them simultaneously by correlating light emission to current.