A Molecularly Imprinted Polymer Electrochemiluminescence Sensor Based on AuNPs@Ru-ZIF-8 for the Rapid Detection of Cyhalothrin Residues in Lycium barbarum L

TL;DR

A new sensor using gold nanoparticles and a special material detects pesticide residues in a medicinal plant quickly and accurately.

Contribution

A novel electrochemiluminescence sensor using AuNPs@Ru-ZIF-8 for rapid and sensitive detection of cyhalothrin in Lycium barbarum L.

Findings

The sensor achieved a linear detection range of 1 × 10−1 to 1 × 10⁴ nM for cyhalothrin.

The limit of detection was as low as 10 pM, demonstrating high sensitivity.

The sensor was validated with spiked recovery experiments and real sample testing.

Abstract

Lycium barbarum L. is a widely used medicinal and edible Chinese medicinal material. However, with consumers’ heightened concern for health and food safety, pesticide residues have become one of the major challenges affecting its quality and safety. Cyhalothrin is a pyrethroid insecticide and a typical type of pesticide with excessive pesticide residues in Lycium barbarum L. Rapid detection of pesticide residues is an effective way to ensure the quality and safety of traditional Chinese medicinal materials. In this work, a molecularly imprinted polymer electrochemiluminescence (ECL) sensor based on gold nanoparticles (AuNPs)@Ru-ZIF-8 was constructed for rapid detection of cyhalothrin residues. The prepared cyhalothrin molecularly imprinted polymers (MIPs) were used as a recognition element and modified on the surface of a glassy carbon electrode (GCE) by an electrochemical polymerization method. AuNPs were utilized to promote the excitation of Ru(bpy)32+ and TPrA in the ECL system, which improved the observability of the light signal. The GCE modified with the metal–organic frameworks (MOFs) ZIF-8 was employed to increase the specific surface area and enhance the electron transfer capacity on the electrode, thereby improving the sensing sensitivity of the sensor. In addition, the luminescent reagent of Ru(bpy)32+ was introduced into the synthesis process of ZIF-8, which caused Ru(bpy)32+ to be tightly bound around it and enhanced the stability of the sensor. Under optimal conditions, the linear detection range of the sensor is 1 × 10−1~1 × 104 nM, with a limit of detection (LOD) of 10 pM. The accuracy of the ECL-MIP sensor has been verified through spiked recovery experiments and actual sample detection. This study has opened up a new approach to rapid detection of pesticide residues in traditional Chinese medicinal materials used for both food and medicine.

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