Development of a highly sensitive lateral flow immunoassay based on receptor-antibody-amorphous carbon nanoparticles to detect 22 β-lactams in milk

摘要

This study aimed to improve the sensitivity of lateral flow immunoassay (LFIA) using two strategies, including using a high sensitivity label and an indirect-labeling format, which were simultaneously applied to develop a highly sensitive LFIA to detect 22 β-lactams. In the new format, β-lactam receptors were used without any labeling, and anti-receptor monoclonal antibodies (mAbs) were labeled with amorphous carbon nanoparticles (ACNs). The new LFIA is based on the following steps: 1) screening mAbs against the receptors for antigen-antibody binding sites away from the active site of the receptors; and 2) detecting immune complexes using receptor-mAb-ACNs. The cut-off values against ampicillin, amoxicillin, benzylpenicillin, dicloxacillin, clox-acillin, oxacillin, nafcillin, cefquinome, cefoperazone, cefapirin, ceftazidime, cephalothin, cefepime, cefoxitin, cefazolin, ceftriaxone, ceftiofur, cefotaxime, cefalexin, imipenem, meropenem, and ertapenem were 1, 2, 2, 10, 10, 10, 10, 3, 3, 3, 5, 10, 10, 20, 20, 20, 30, 30, 100, 10, 15, and 15 ng/mL, respectively, which is significantly lower than that of receptor-mAb-colloidal gold-LFIA using the same immune reagents.