A highly sensitive lateral flow immunoassay based on a group-specific monoclonal antibody and amorphous carbon nanoparticles for detection of sulfonamides in milk

To meet high-throughput screening of the residues of sulfonamides (SAs) with high sensitivity toward sulfamethazine (SM2) in milk samples, a new highly sensitive lateral flow immunoassay (LFA) based on amorphous carbon nanoparticles (ACNs) was developed. First, a group-specific monoclonal antibody 10H7 (mAb 10H7) that could recognize 25 SAs with high sensitivity toward SM2 (IC50 value of 0.18 ng/mL) was prepared based on H1 as an immune hapten and H4 as a heterologous coating hapten. Then, mAb 10H7 was conjugated to ACNs as an immune probe for LFA development. Under the optimized conditions, the LFA could detect 25 SAs with the cut-off value toward SM2 of 2 ng/mL, which could meet the requirement for detection of SAs. In addition, the LFA developed was also used for screening SAs' residues in real milk samples, with results being consistent with HPLC-MS/MS. Thus, this LFA can be used as a high-throughput screening tool for detection of SAs.

Automated summary

A new highly sensitive lateral flow immunoassay (LFA) based on amorphous carbon nanoparticles (ACNs) was developed for high-throughput screening of sulfonamides (SAs) residues in milk samples, especially sulfamethazine (SM2). This LFA utilized a group-specific monoclonal antibody 10H7 (mAb 10H7) conjugated to ACNs as an immune probe, achieving a sensitive detection with a cut-off value of 2 ng/mL for 25 SAs. The LFA was successfully applied for screening SAs residues in real milk samples, showing consistent results with HPLC-MS/MS.