Abstract: Methods are disclosed for producing electrochemiluminescence by electrochemically oxidizing an acridan compound at an electrode in the presence of a peroxide. Maintaining a sufficiently positive potential results in continuous oxidation of the acridan compound to an acridinium compound which reacts with peroxide to produce the luminescence. Light emission can be reversibly and repeatedly cycled on and off by sweeping the potential between two values. The acridan compounds can be provided with a labeling group for linking to an analyte or analyte binding partner. The present electrochemiluminescent reaction can find use in assay methods for detecting analytes by immunoassays and nucleic acid assays.

Abstract: A Bis (cyclopentadienyl) metal complex of a derivative thereof is used as a label in an assay utilizing electrichemiluminescence or fluorescence detection means. The Bis (cyclopentadienyl) metal complex may comprise ferrocene or a derivative thereof which gives rise to a ferricinium ion on electrochemical oxidation.