Development of immunochromatographic assays for the detection of imidacloprid in soil chemical barrier

Abstract

A soil chemical barrier is the most important and common way to control termites; fast and on-site detection methods are significant tools to verify pesticide content meeting the standard requirements. In this study, conventional and enhanced immunochromatographic assays (ICAs) containing two test lines (TLs) were developed to semi-quantitatively detect imidacloprid in soil chemical barrier, and detection results were quantified by a smart phone. According to the results, the disappearance concentrations of first TL (TL-1) and second TL (TL-2) in an enhanced ICA and conventional ICA were 5 and 20 ng/mL and 20 and 80 ng/mL with the naked eye. The sensitivity of TL-2 was four times that of TL-1 in both ICAs, consistent with the maximum and minimum concentration differences for imidacloprid in Jiangsu province's "the technical regulation of assay and evaluation on chemical soil barrier of termite prevention treatment in buildings". The results of TLs can be used to judge whether the amount of imidacloprid in soil chemical barrier meets the standard. Enhanced and conventional ICAs were available for further quantitative testing with a smart phone, and the limit of detection (LOD) was 0.74 and 3.17 ng/mL, respectively. Moreover, some soil chemical barrier samples from several areas in Wuxi, Jiangsu province, were used to test by ICAs and high-performance liquid chromatography (HPLC), and the results of ICAs correlated well with HPLC.

Identification and Application of Two Promising Peptide Ligands for the Immunodetection of Imidacloprid Residue

“…The ninety-six-well microplates were purchased from Corning Costar (Corning, NY, USA). The mAb 3D11B12E5 purified by protein A column and phage-displayed cyclic 8, 9, 10-residue random peptide libraries were prepared and stored in our own laboratory [ 13 , 30 ]. The sequencing primer was synthesized by Genscript Bio.…”

Development of Fluorescence Polarization Immunoassay for Imidacloprid in Environmental and Agricultural Samples

“…IMI and its other structural analogs were purchased from Dr. Ehrenstorfer GmbH (Germany). The anti-IMI mAb (3D11B12E5) and IMI hapten were prepared as described previously (Yang et al, 2018). The haptens of ACE and THI were prepared as described previously (Wanatabe et al, 2001;Kim et al, 2003).…”

“…And then, 20 mL of acetonitrile were transferred and evaporated to dryness with a rotary evaporator at 40 • C. The extracts were dissolved with 5 mL of acetonitrile:water (70:30, v/v) and the concentrations of IMI were detected by HPLC with a Eclipse plus C18 column (4.6 mm × 250 mm × 5 µm). A mixture of acetonitrile:water (70:30, v/v) was used as the mobile phase at a flow rate of 1.0 mL/min at 30 • C. The detection wavelength was 270 nm and the injection volume was 20 µl (Yang et al, 2018).…”

“…There are also many immunoassays that have been established for the detection of IMI, such as enzyme-linked immunosorbent assay (ELISA) (Watanabe et al, 2004;Brian et al, 2009;Navarro et al, 2013), and immunochromatographic assay (ICA) (Xu and Xu, 2012;Fang et al, 2015;Yang et al, 2018). However, ELISAs require long incubation time and multi-step operation, and ICAs generally provide qualitative or semi-quantitative results.…”