Electrochemical luminescence sensor for the detection of Allure Red: double luminescence cooperative amplification strategy of self-supporting material ZnCuO and CdTe@MWNTs.

The self-supporting material ZnCuO was synthesized through the methods of electrospinning combined with high-temperature calcination. A novel sensitive electrochemiluminescence (ECL) sensor based on ZnCuO and CdTe@MWNTs was constructed by the multi-step amplification strategy. First, ZnCuO and CdTe served as the ECL groups to construct the sensor, yielding a larger signal of the sensor in the presence of the co-reactant KSO. Multi-walled carbon nanotubes (MWNTs) were introduced as a carrier to increase the signal value of the sensor further. The synergistic action of CdTe@MWNTs and ZnCuO made the system obtain the maximum initial signal. With the addition of Allure Red (AR), the ECL signal decreased. The quenching phenomenon was not only due to the large organic molecule AR occupying the active sites of ZnCuO and CdTe, but also, more importantly, because the sensor existed as an ECL-RET mechanism between CdTe and AR. The response mechanism and experimental conditions of the system were also investigated. Under optimal conditions, the sensor showed a linear relationship between the ECL signal change and the logarithm of AR concentration in the range 1.0 × 10 to 1.0 × 10 mol L, the linear equation was ∆I = 15,295.54 + 956.42 log C, and the correlation coefficient was 0.9928. The lowest detection limit of (S/N = 3) was 1.67 × 10 mol L. Satisfactory results were obtained for the analysis  of beverages.