Development of a sensitive monoclonal antibody-based immunochromatographic strip for neomycin detection in milk

Abstract

To improve the detection sensitivity of neomycin (NEO) in milk, we produced a sensitive monoclonal antibody (mAb) against NEO and developed a lateral flow immunoassay based on amorphous carbon nanoparticles (ACNPs-LFA). First, we conjugated NEO to carrier protein to prepare mAbs. We obtained six mAbs: mAb 1C6, mAb 1D3, mAb 2D3, mAb 4D5, mAb 5D1, and mAb 5H1. We characterised the mAbs by indirect competitive enzyme-linked immunosorbent assay and selected the most sensitive mAb based on the half-maximal inhibitory concentration (IC50). We selected mAb 4D5 (IC50 = 0.15 ng/mL) for the development of LFA. MAb 4D5 was labelled with ACNPs (ACNPs-mAb 4D5) by electrostatic absorption. Under optimised conditions, 5.4 μg mAb 4D5 coupling with 1 mL ACNPs, NEO-OVA at concentration of 80 μg/mL, 3 μL ACNPs-mAb 4D5 were used to develop LFA. The cut-off value was 8 ng/mL. Therefore, our developed ACNPs-LFA is suitable for on-site detection of NEO residues.

Keywords

• Lateral flow immunoassays
• amorphous carbon nanoparticles
• monoclonal antibody
• neomycin
• milk
• detection