Trace Immunosensing of Multiple Neonicotinoid Insecticides by a Novel Broad-Specific Antibody Obtained from a Rational Screening Strategy

Abstract

Residues of neonicotinoid pesticides have potential risks to food, environmental and biological safety. In this study, the hapten toward imidacloprid was adopted to gain antibodies. After molecular modeling, the electrostatic potentials of eight commonly-used neonicotinoid pesticides were individually calculated to analyze the structural similarity. Two representative compounds (imidacloprid and acetamiprid) with moderate similarity were rationally selected for hybridoma screening. Using this strategy, four clones of broad-specific monoclonal antibodies (mAbs) against multiple neonicotinoids were obtained, and the clone 6F11 exhibited the broadest spectrum to six neonicotinoid pesticides and two metabolites, with half-maximal inhibitory concentrations (IC50) ranging from 0.20 to 5.92 ng/mL. Then, the novel antibody gene was sequenced and successfully expressed in full-length IgG form using mammalian cells. Based on the sensitive recombinant antibody, a gold lateral-flow immunosensing strip assay was developed and it was qualified for rapid detection of imidacloprid, clothianidin or imidaclothiz residues in food samples.

Insights into the Binding Profile of Anti-chlorpyrifos Recombinant Antibodies: From Computational Simulation to Immunoassay Validation

“…The state-of-the art in silico technologies are powerful tools for interpreting the interactions between receptors and ligands at the molecular level. Based on molecular docking, virtual screening is an attractive methodology for the high-throughput identification of active compounds in drug discovery and point-of-care testing. , In the field of immunochemistry, computational techniques have been widely applied to elucidate antibody–antigen binding mechanisms and assist rational hapten or competitor design. , They provide insights into the effects of molecular structure on biological activity that are difficult or impossible to obtain in other ways, which are important for either improving assay sensitivity or regulating specificity . However, there are few studies on the application of these techniques to antibody validation and characterization.…”

“…It conquered the bottlenecks of poor structural stability, unsatisfactory solubility, low affinity, and short half-life that conventional single-chain variable fragments (scFvs) and antigen-binding fragments (Fabs) might have. 7 In recent years, few full-length IgG rAbs for pesticides determination (e.g., neonicotinoids, 8,9 N-methyl carbamates, 10 pyraclostrobin 11 and S-metolachlor 12 ) have been reported, but rAbs for chlorpyrifos monitoring are lacking. Active antibody variable regions (VRs) serve as the fundamental components in the preparation of rAbs.…”

“…17,18 In the field of immunochemistry, computational techniques have been widely applied to elucidate antibody−antigen binding mechanisms 19 and assist rational hapten or competitor design. 9,20 They provide insights into the effects of molecular structure on biological activity that are difficult or impossible to obtain in other ways, which are important for either improving assay sensitivity or regulating specificity. 21 However, there are few studies on the application of these techniques to antibody validation and characterization.…”