Cathodic electrochemiluminescence based on resonance energy transfer between sulfur quantum dots and dopamine quinone for the detection of dopamine

Herein, an ultrasensitive electrochemiluminescence (ECL) sensor was established for the determination of dopamine using sulfur quantum dots (SQDs) as the luminophore. The detection mechanism highlights how dopamine can be oxidized into dopamine quinone (DQ) and quenches the ECL signal of SQDs. Under the optimized experimental conditions, the ECL signal of SQDs was used for the detection of dopamine in the linear range of 1 × 10−10 to 1 × 10−3 M with a detection limit of 2.5 × 10−11 M (S/N = 3). The proposed method has excellent specificity, a low detection limit, and high sensitivity when applied in the analysis of real samples and is applicable in the development of novel ECL luminophores as well as the improvement of human health.