Ultrafast Response in AC-Driven Electrochemiluminescent Cell Using Electrochemically Active DNA/Ru(bpy)3 2+ Hybrid Film with Mesoscopic Structures

Electrochemiluminescence (ECL) refers to light emission induced by an electrochemical redox reaction. The stability, emission response, and light intensity of the ECL device are known to be improved by using an alternating current (AC) voltage. In this paper, an AC-driven ECL device is fabricated with DNA/Ru(bpy)(3) (2+) hybrid film-modified electrode. The Ru(bpy)(3) (2+) complex exhibits significant electrochemical reactivity in the DNA/Ru(bpy)(3) (2+) hybrid film prepared by electrochemical adsorption. The hybrid film contains unique micrometre-scale aggregates of Ru(bpy)(3) (2+) in DNA matrix. The physicochemical properties of the hybrid film and its AC-driven ECL characteristics in the electrochemical device are studied. Orange-coloured ECL is observed to be emitted from only the aggregated structures in the hybrid film at the high AC frequency of 10 kHz, which corresponds to a response time shorter than 100 mu s.