Sensitive Detection of Melamine at Surface Plasmon Resonance Chips Pre-immobilized with Bovine Serum Albumin-Melamine Conjugate

Surface plasmon resonance (SPR) assay of melamine was carried out based on the competitive reaction in which the assayed melamine with varying concentrations in solution competed with the pre-immobilized bovine serum albumin (BSA)- melamine conjugate for the anti-melamine monoclonal antibodies (mAbs) in solution. The BSA-melamine conjugate was first immobilized on the carboxymethylated dextran-covered SPR chips, and then followed by the injection of the mixed solution of melamine and anti-melamine mAbs with a fixed concentration. By examining the SPR signals caused by the attached mAbs, the concentrations of melamine could be determined. The linear range of the assay was 0.25–13 nM and 13–250 nM. The chips could be regenerated via injection of NaOH solution, thus, high-throughput assays could be attained. The developed method is convenient and cost-effective, holding great promise for determination of small molecules with low concentrations.

Graphical AbstractAn SPR assay of melamine was carried out base on the competitive reaction in which the mixed solution of melamine and the anti-melamine mAbs was injected into the fluidic channels covered with the BSA-melamine conjugate. By examining the SPR signal caused by the attached mAbs, the concentrations of melamine could be determined.Figure optionsDownload full-size imageDownload as PowerPoint slide