LAUSR

Abstract Ag 2 Te quantum dots (QDs) were synthesized through ion-exchange method with CdTe QDs as precursors. The same size of Ag 2 Te QDs can be obtained from the different sizes of precursors, which results in the similar fluorescent behaviors. The maximum FL peak of Ag 2 Te QDs is red-shifted from 510 nm to 950 nm with the increase of ion-exchange time. Strong cathodic ECL of Ag 2 Te QDs can be observed in neutral condition with K 2 S 2 O 8 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 K 2 S 2 O 8 concentration. Resonance energy transfer can occur between Ag 2 Te 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.