Graphene quantum dots enhanced electrochemiluminescence of cadmium sulfide nanocrystals for ultrasensitive determination of pentachlorophenol

Abstract

An ultrasensitive electrochemiluminescence (ECL) sensor based on the ECL amplifying behavior of the graphene quantum dots–CdS nanocrystals (GQDs–CdS NCs) was constructed for the detection of pentachlorophenol (PCP). Because of the presence of doped GQDs, the resulting GQDs–CdS NCs exhibited 5-fold enhanced ECL intensity than pure CdS NCs with the ECL onset potential positively shifted by 80 mV. Furthermore, based on the effective inhibition of the ECL response of GQDs–CdS NCs film by PCP, a simple method for ultrasensitive determination of PCP was devised, which showed a wide linear range of 0.01–500 ng mL⁻¹ and a low detection limit of 3 pg mL⁻¹ (S/N = 3) with good stability, reproducibility and applicability for PCP detection in real water samples. Thus, it can be expected that GQDs-based composites with excellent performance may play a more important role in pesticide determination.