Electrogenerated chemiluminescence of Ag2Te quantum dots and its application in sensitive detection of catechol

Ag2Te quantum dots (QDs) were synthesized through ion-exchange method with CdTe QDs as precursors. The same size of Ag2Te QDs can be obtained from the different sizes of precursors, which results in the similar fluorescent behaviors. The maximum FL peak of Ag2Te QDs is red-shifted from 510 nm to 950 nm with the increase of ion-exchange time. Strong cathodic ECL of Ag2Te QDs can be observed in neutral condition with K2S2O8 as coreactant, which is much stronger than that of CdTe QDs. The ECL signals exhibit close relationship with the reaction time, the modified amount of QDs, and the K2S2O8 concentration. Resonance energy transfer can occur between Ag2Te QDs ECL and catechol resulting in the decreased ECL signals, which can be used in the sensitively detection of catechol. Under the optimal conditions, the decreased ECL signals varied linearly with the concentrations of catechol in the range of 1.0 × 10−9−1.0 × 10−5 mol L−1 with a detection limit of 0.31 nM (3σ). The ECL sensor exhibited satisfied stability, repeatability and selectivity in the detection of catechol.