Electrochemiluminescence of N-(4-Aminobutyl)-N-ethylisoluminol Investigated by Electrochemical Impedance Spectroscopy

Abstract

The electrochemiluminescence (ECL) of N-(4-aminobutyl)-N-ethylisoluminol (ABEI) in a hydrogen peroxide solution was investigated by electrochemical techniques in the frequency domain. Parallel Pt wire electrodes in a flow-type spiral cell were used for ECL measurements. A superoxide ion, O₂^-, was generated by electrooxidation on Pt, and ABEI fluo-resced by a reaction with O₂^-. An ECL impedance L, which is the ratio of the luminescence amplitude to the current in the frequency domain, is proposed in the present paper. The theoretical expression of L was derived to be L=a₁/(1+j w/k), where a₁ is a constant and k is the reaction rate constant of ABEI and O₂^-. By comparing the above equation with the experimental results, the rate constant k was determined.