Monoclonal antibody production based on different chelators and development of time-resolved fluorescent microsphere...

Lead contamination in agricultural products and foods is increasing, which has impacted on human health. To effectively detect lead residues in foods, time-resolved fluorescent microspheres lateral flow immunoassays (TRFMs-LFIAs) were developed utilizing two antibodies produced based on two chelators. The qLOD (quantitative limit of detection) of two TRFMs-LFIAs were 0.24 ng/mL and 0.09 ng/mL, respectively. Their vLOD (visual limit of detection) were 20 ng/mL and 10 ng/mL, respectively. They showed no significant cross-reactivity with 12 tested metal ions. The TRFMs-LFIAs demonstrated strong concordance with graphite furnace atomic absorption spectrometry (GFAAS) in detecting Pb²⁺ in real samples. They could meet the specific and rapid detection needs for Pb²⁺ in the field. Furthermore, the main interaction forces and key amino acids involved in the interaction between antibodies and lead-chelator complexes were investigated using molecular docking. This study contributed to the development and understanding of heavy metal immunoassays.