Anodic near-infrared electrochemiluminescence from CdTe/CdS coresmall/shellthick quantum dots and their sensing ability of Cu2+

Anodic near-infrared electrochemiluminescence (NECL) from 3-mercaptopropionic acid (MPA)-capped CdTe/CdS coresmall/shellthick quantum dots (QDs) without any co-reactants were studied in aqueous solution for the first time. A stable and intensive anodic NECL emission at +1.32 V with an onset potential of +0.84 V was observed in pH 7.4 PBS at an indium tin oxide electrode, which results from the annihilation process between the oxidation products of QDs and the produced QDs anions. Various influencing factors, such as pH, electrolyte, scan rates and electrode materials on the NECL were investigated. Based on the selective quenching by Cu2+ to the NECL emission from the QDs, a simple and sensitive method for the determination of Cu2+ was developed. Moreover, as a practical application, the proposed method was used to monitor Cu2+ level in lake water and milk with satisfactory results obtained.