A sensitive method to monitor catechol by using graphitic carbon nitride quantum dots as coreactants in Ru(bpy)32+-based electrochemiluminescent system

Abstract Graphitic carbon nitride quantum dots (g-CNQDs) with special structures have exhibited fascinating advantages over the common QDs. In this work, we report a novel Ru(bpy)32+/g-CNQDs electrochemiluminescence (ECL) system, and the effect of g-CNQDs on the ECL signal of Ru(bpy)32+ was discussed. It was found that g-CNQDs containing in proposed ECL system played an important coreactant role in ECL signal enhancement of Ru(bpy)32+, which was proved by electrochemical, ultraviolet, and ECL experiments. Based on the quenching effect of catechol on the ECL signal of Ru(bpy)32+/g-CNQDs, a quenching-based ECL system was designed for catechol determination. The ECL sensing system demonstrated high sensitivity to catechol, with a linear range from 10 nM to 2 mM and a detection limit of 2.5 nM (S/N = 3). The sensor was adopted for catechol analysis in tea samples with satisfactory results.