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A novel visual flow-through column biomimetic immunoassay using horseradish peroxidase-labeled clenbuterol (HRP-CLB) as a tracer and molecularly imprinted polymers (MIPs) with high specificity as the artificial antibody has been developed for rapid detection of CLB. Different intensities of blue color products on test layer of the column could be observed after reaction. This optimized assay provided a preliminary qualitative result in the concentration range of 0 to 1000 μg/L by judging color density of the test layer without any equipment, and the detection could be finished within 15 min. This assay was evaluated using CLB spiked water samples and results were comparable to high performance liquid chromatography method. The visual detection limit of 5 μg/L in water sample was obtained. This developed flow-through column biomimetic immunoassay was demonstrated as a suitable tool for rapid, sensitive, low-cost, and qualitative determination of CLB residues on site.

Deltamethrin, one of the most toxic pyrethroids, is commonly used to inhibit pests in wheat. However, the trace levels of deltamethrin in wheat is alarming to human health. In this study, surface-enhanced Raman spectroscopy (SERS)-active silver nanoparticles-plated-zinc oxide nanoflowers (Ag@ZnO NFs) nano-sensor were employed for rapid and sensitive quantification of deltamethrin in wheat. To sufficiently utilize the chemical-related information in SERS spectra, various spectral pretreatment and chemometric models were studied. The mean centering (MC) coupling successive projection algorithm-partial least squares regression (SPA-PLS) provided optimal predictive performance (correlation coefficient of prediction (Rp) = 0.9736 and residual predictive deviation (RPD) = 4.75). The proposed method achieved the limit of detection (LOD) = 0.16 μg·kg−1, the recovery of predicted results was in the range of 96.33–109.17% and the relative standard deviation (RSD) was