ELECTROGENERATED CHEMILUMINESCENCE .57. EMISSION FROM SODIUM PHENYLANTHRACENE-2-SULFONATE,THIANTHRENECARBOXYLIC ACIDS, AND CHLORPROMAZINE IN AQUEOUS-MEDIA

The anodic oxidation of aqueous sodium 9,10-diphenylanthracene-2-sulfo nate (DPAS) and 1- and 2-thianthrene-carboxylic acid (1- and 2-THCOOH) in the presence of tri-n-propylamine as a coreactant in aqueous solut ion produces electrogenerated chemiluminescence (ECL), In addition, th e cathodic reduction of DPAS in the presence of peroxydisulfate as a c oreactant also produces ECL in an acetonitrile-water solution (1:1 v/v ), For DPAS, both the oxidative and the reductive ECL spectra are char acteristic of DPAS fluorescence, with peak intensities at 430 nm, In c ontrast, the ECL spectra for 1- and 2-THCOOH are significantly red-shi fted from the fluorescence spectra, indicating that the emission arise s from a product of THCOOH rather than the excited state of the intact acid, The oxidation of chlorpromazine produces an ECL emission in the absence of an added coreactant following an unprecedented ''self-anni hilation'' mechanism. These new aqueous ECL reactions should be useful in the design of new labels for ECL analysis of biomolecules (i.e., i mmunoassays, DNA probes).