ELECTROCHEMICAL LIGHT EMITTING METHOD AND IMMUNOASSAY METHOD

PURPOSE:To enable the exact detection, determination, etc., of antigens/ antibodies by disposing a pair of electrodes in a soln. of a firefly luciferin compd. and impressing voltage between the electrodes so that the firefly luciferin compd. emits light electrochemically. CONSTITUTION:The firefly luciferin {4,5-dihydro-2-(6-hydroxy-2-benzothiazole)-4- thiazole carboxylic acid)} expressed by the formula is prepd. to the soln. by using an aq. buffer soln. of 6-8pH and the electrodes 1 for electrochemical luminous detection are disposed therein. The electrodes 1 are integrally provided with a light-transmittable working electrode 2, a counter electrode 3 and an optical fiber 4. The light exit face side of the fiber 4 is connected to a photodetecting part 23 and the electrodes 2, 3 are connected via lead wires 5 to voltage pulse generators 22, 21. Excitation active species are first formed when the prescribed negative voltage is impulsively impressed to the electrode 2. The active species generated by impression of the positive voltage reacts with the excitation active species to generate light emission. The quantity of the emitted light is measured via the fiber 4, by which the concn. of the firefly luciferin is detected.