Light enhanced electrochemistry and electrochemiluminescence of luminol at glassy carbon electrodes

We report in this work the enhancement effect of light irradiation on the electrochemistry and electrochemiluminescence (ECL) of luminol at the bare glassy carbon electrode (GCE). Light irradiation on the GCE surface induced the formation of hot electron-hole pairs. In alkaline solutions, hot holes can oxidize hydroxide anions to hydroxyl radicals that are capable of promoting the oxidation of luminol to generate larger current and stronger ECL. Moreover, the stability of current and ECL is also significantly improved upon light irradiation. This study provides a simple method to enhance the electrochemistry and ECL of luminol that have promise in improving the sensitivity of luminol-based chemical analysis and bioanalysis.