Construction of an electrochemical biosensor based on Au@MOF-COF nanocomposites for the detection of acetamiprid in traditional Chinese medicine.

Abstract

The development of high-performance electrochemical aptamer-based sensors represents one of the effective strategies for addressing the intractable issue of pesticide residues that pose a threat to human health. Functional nanomaterials are pivotal to enhancing the analytical performance of such sensors. Herein, a multifunctional Au@MOF-COF nanocomposite was rationally designed and synthesized by integrating the inherent advantages of gold nanoparticles, metal-organic frameworks (MOFs), and covalent-organic frameworks (COFs). By stably immobilizing the specific aptamer on the composite matrix and constructing a signal amplification mechanism based on the dual catalytic cycle pathway, quantitative detection was achieved in the range of 10-1000 ng/L with a limit of detection (LOD) of 7.260 ng/L (S/N = 3), exhibiting excellent repeatability and high selectivity against structurally similar pesticides. This sensor was successfully applied to the quantitative detection of acetamiprid in actual traditional Chinese medicine samples (e.g., Panax ginseng, Astragalus membranaceus, Lycium barbarum), with recoveries ranging from 97.2% to 107.4%. The strategy proposed in this study provides a new direction for the detection of pesticide aptasensors.