Development and comparison of two nanomaterial label-based lateral flow immunoassays for the detection of five antibacterial synergists

Abstract

The label is a significant factor when analyzing the performance of lateral flow immunoassays (LFIAs) in practical applications. In this study, we first produced a broad-specificity monoclonal antibody (mAb) against five antibacterial synergists (ASGs) whose subclass was IgG2b and affinity constant was 1.30 × 10¹⁰ L mol⁻¹. Then, time-resolved fluorescent microspheres (TRFMs) and colloidal gold nanoparticles (CGs) were used to label the mAbs, and the two different label-based LFIAs were developed and compared for their ability to quantitatively detect ASGs in chicken samples. Under optimal conditions, the limits of detection (LODs) of the TRFM-based LFIA were 0.001–0.01 μg kg⁻¹ and those of the CG-based LFIA were 0.01–0.11 μg kg⁻¹. The sensitivity of the TRFM-based LFIA was higher than that of the CG-based LFIA. In addition, owing to the visible test zone of the CG-based LFIA, qualitative results can be easily obtained. Analysis of real samples showed that results from the two LFIAs were consistent with that of an ic-ELISA.