Rapid detection of matrine in honey and tea using a gold-based immunochromatographic sensor

The European Union (EU) has detected matrine (MAT) in honey and tea exported from China, which is neurotoxic, hepatotoxic, developmentally toxic, and reproductively toxic. To develop a rapid method for the detection of MAT in honey and tea, we designed and analyzed hapten in terms of structure-function similarity, surface electrostatic potential, 3D conformation, and Mulliken atomic charges, prepared a monoclonal antibody (mAb) with high sensitivity (IC₅₀ = 0.59 μg/L) and specificity to recognize MAT, and developed an immunosensor based on gold nanoparticles (GNP-based immunosensor) for the rapid qualitative detection of MAT in honey and tea samples with visual limit of detection (vLOD) of 2 and 5 μg/kg, respectively. The accuracy of the GNP-based immunosensor was verified by spiking recovery experiments. The GNP-based immunosensor is instrument-free and can be completed within 8 min with the advantages of convenience, rapidity and high sensitivity, which provides a tool for MAT monitoring of honey and tea in China.