PROBLEM TO BE SOLVED: To provide a transducer capable of functioning as an electronic sensor and a redox cycling sensor.SOLUTION: A transducer comprises two electrodes 115 and 120 separated through a nano-gap. Molecular binding regions 130 proximate to and inside the nano-gap are provided. Arrays of individually addressable nano-gap transducers can be disposed on integrated circuit chips 105 and operably coupled to the integrated circuit chip.SELECTED DRAWING: Figure 1