Sensitive detection of hydroquinone based on electrochemiluminescence energy transfer between the exited ZnSe quantum dots and benzoquinone

Abstract

We proposed a signal amplification strategy designed for sensitive electrochemiluminescence (ECL) detection of hydroquinone (HQE) in water. The detection mechanism is based on the ECL energy transfer (ET) can generate between the excited ZnSe quantum dots (QDs) and the benzoquinone (BQE) obtained by oxidation of hydroquinone. The ECL-ET resulted in the quenching effect of the cathodic ECL of ZnSe QDs using S2O82− as co-reactant. Because the graphene of outstanding electronic conductivity can accelerate the electron transfer rate between the ZnSe QDs on electrode and S2O82− in the electrolyte solution, so that larger than 3-fold enhance in ECL intensity was obtained after ZnSe QDs decorated on graphene. Under the optimal conditions, the linear range for hydroquinone was 1 × 10−9–1 × 10−6 mol/L with a detection limit of 3.4 × 10−10 mol/L (S/N = 3). The proposed ECL sensor showed the performance advantages of fine selectivity, high sensitivity, low detection limit, wide linear range and good reproducibility. It will hold an enormous potential in the field of environmental analysis.