Fluorescent aptamer-modified mesoporous silica nanoparticles for quantitative acetamiprid detection

Acetamiprid (ACE) is widely used to control aphids, brown planthoppers, and other pests in agricultural production. However, ACE is difficult to degrade in the environment, resulting in excessive residue, which causes acute and chronic toxicity to human beings and non-target organisms. Therefore, the development of a rapid, convenient, and highly sensitive method to quantify ACE is essential. In this study, aminated mesoporous silica nanoparticles (MSNs-NH 2 ) were synthesized by one-pot method, and 6-carboxyl fluorescein modified aptamers (FAM-Apt) of ACE were adsorbed on the surface of MSNs-NH 2 by electrostatic interaction. Finally, a simple and sensitive fluorescence analysis method for the rapid detection of ACE was established. In the absence of ACE, the negatively charged FAM-Apt was electrostatically bound to the positively charged MSNs-NH 2 , followed by centrifugation to precipitate MSNs-NH 2 @FAM-Apt, and no fluorescent signal was detected in the supernatant. In the presence of ACE, the specific combination of FAM-Apt with ACE was greater than its electrostatic interaction with MSNs-NH 2 , so that FAM-Apt was separated from MSNs-NH 2 , and the supernatant had strong fluorescence signal after centrifugation. For ACE detection, the linear concentration range was 50–1100 ng/mL, and the detection limit (LOD) was 30.26 ng/mL. The method exhibited high sensitivity, selectivity and reproducibility, which is suitable for practical sample analysis and provides guidance for rapid detection of pesticide residues. Graphical abstract