Turn-on electrochemiluminescence sensing of Cd(2+) based on CdTe quantum dots.

A simple and sensitive method for the detection of cadmium ion was proposed based on the electrochemiluminescence (ECL) of thioglycolic acid capped-CdTe quantum dots (CdTe QDs). The ECL of CdTe QDs was firstly quenched by introduction of S(2)(-) and was restored due to following addition of Cd(2+), on the basis of which, a "turn-on" ECL method for the detection of Cd(2+) was demonstrated. The ECL of CdTe QDs exhibited linear response toward Cd(2+) concentration in the range from 6.3nM to 3.4μM (R=0.999) with a detection limit of 2.1nM. The proposed assay was simple, sensitive, selective, and practicable in real water samples.