Novel electrochemiluminescence platform utilizing AuNPs@Uio-66-NH bridged luminescent substrates and aptamers for the detection of pesticide residues in Chinese herbal medicines.

A large number of Chinese herbal medicines (CHMs) are included in daily recipes, but their pesticide residues have aroused more and more concerns. In this paper, an electrochemiluminescence aptasensor was constructed for the trace detection of acetamiprid (ACE) in Angelica sinensis and Lycium barbarum. Possessing a large specific surface area, UiO-66 was modified with amino groups to improve biocompatibility, and the addition of AuNPs allowed UiO-66-NH to catalyze the formation of excited states of luminescent molecules (TPrA; Ru(bpy)), and AuNPs@UiO-66-NH was used to bridge the aptamer (Au-S) and luminescent substrate (peptide bond). The conventional luminescent reagent Ru(bpy) was doped with multi-walled carbon nanotubes (MWCNTs) to obtain a more powerful and stable light signal. After optimizing the experimental parameters, the aptasensor could give results in 10 min with a detection range from 1×10-1×10 nM and a lower limit of detection (LOD) of 0.8 pM. The LOD of the study was at least one order of magnitude lower than that of the fluorescence detection method. Furthermore, the accuracy of the aptasensor was validated for spiked recovery experiments.