Novel electrochemiluminescence platform utilizing AuNPs@Uio-66-NH2 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-NH₂ to catalyze the formation of excited states of luminescent molecules (TPrA^⁎; Ru(bpy)₃^2+⁎), and AuNPs@UiO-66-NH₂ was used to bridge the aptamer (Au-S) and luminescent substrate (peptide bond). The conventional luminescent reagent Ru(bpy)₃²⁺ 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^-2-1×10⁴ 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.