Sub-microliter electrochemiluminescence detector : A model for small volume analysis systems

A small volume, electrochemical cell for the generation and detection of electrochemiluminescence from tris(2,2′-bipyridyl) ruthenium(II) has been fabricated. The flowcell is a poly(methyl methacrylate) (PMMA)–acetate–PMMA sandwich construct, containing two platinum, thin-film electrodes. Operation of the microchip establishes sub-microliter detection of tris(2,2′-bipyridyl) ruthenium(II) electrochemiluminescence in continuous flow. Initial experiments demonstrate a detection limit of 5 × 10–13M at an effective cell volume of 100 nl. This corresponds to the detection of only 30 000 molecules.