A system and method are provided for selectively functionalizing a transducer microarray. The method provides a microarray including a field of transducers exposed to a shared local environment. A difference in the pH associated with the transducers is created. As a result, functional molecules are selectively bound to transducers in response to the pH associated with the transducers. In one aspect, the micro-array also provides a field of transducer pH-generating electrodes, one pH-generating electrode for each transducer, and a counter electrode. The difference in pH associated with the transducers is created by selectively applying a voltage potential between pH-generating electrodes and the counter electrode, to create a difference of pH in regions adjacent to the transducers.