Solid-state electrochemiluminescence sensor based on TiO2@CdSe and Ru(bpy)32+@Ag NPs for ultrasensitive detection of malathion.

To sensitively monitor trace-level of malathion (MAT) in vegetable samples, an ultrasensitive solid-state electrochemiluminescence (ECL) sensor was proposed based on TiO2@CdSe and Ru(bpy)32+@Ag NPs. In this system, the introduction of Ag NPs enhanced the initial ECL signal of Ru(bpy)32+- tripropylamine (TPrA). When TiO2@CdSe was introduced into the system, the ECL signal was further enhanced, which may be due to the synergistic effect of the two complexes. Based on the fact that the addition of MAT causes ECL strength to decrease, a ECL sensor for the ultrasensitive trace detection of MAT has been successfully established. Under the optimized conditions, a wide liner detection range of MAT concentrations from 4.0 × 10-14 to 4.0 × 10-9 mol L-1 and a low detection limit (S/N = 3) of 1.3 × 10-14 mol L-1 were obtained. The ECL sensor has been applied to the detection of vegetable samples and satisfactory results were obtained.