Enhanced electrochemiluminescence from reduced graphene oxide-CdTe quantum dots for highly selective determination of copper ion.

An electrochemiluminescence (ECL) sensor based on reduced graphene oxide-CdTe quantum dots (RGO-CdTe QDs) composites for detecting copper ion (Cu2+ ) was proposed. The ECL behaviours of the RGO-CdTe QD modified electrode were investigated with H2 O2 as the co-reactant. Quantitative detection of Cu2+ was realized as Cu2+ could effectively quench the ECL signal of the RGO-CdTe QDs. A wide linear range of 1.00 × 10-14 to 1.00 × 10-4  M (R = 0.9953) was obtained under optimized conditions, and a detection limit (S/N = 3) was achieved of as low as 3.33 × 10-15  M. The proposed sensor also exhibited good stability and selectivity for the detection of copper ions. Finally, the analytical application of the proposed sensor was also evaluated using river water.