Electrochemiluminescence on-a-chip: towards a hand-held electrically powered optofluidic source.

We report a microfluidic platform that integrates several parallel optical sources based on electrochemiluminescence (ECL) of 9,10-diphenylanthracene (DPA) as luminophore agent. The annihilation of DPA radicals provides a low wavelength emission at λ=430 nm in the blue-visible range. By varying the distance between electrodes for each ECL integrated source, this glass/PDMS/glass platform enabled a systematic investigation of the main electrochemical parameters involved in ECL. These parameters have been studied either in a static mode or in a dynamic one. Even at slow flow rate (~2 µl s(-1)), the renewal of electroactive species could be easily promoted inside the microfluidic channel which gives rise to a stable optical intensity for several minutes. Compared with traditional optically pumped dye sources, this microfluidic system demonstrates that ECL can be easily implemented on chip for producing much compact optofluidic sources. Such simply electrically powered system-on-chip would surely encourage the future of hand-held µTAS devices with integrated fast detection and embedded electronics.