Gold Magnetic Nanoparticles-based Chemiluminescent Immunoassay for Detection of Chloramphenicol in Milk

chemiluminescent immunoassays (CLIA) based on gold magnetic nanoparticles (Au-MNPs) were developed for rapid analysis of chloramphen icol (CAP) in milk sample. Anti-CAP antibodies were immobilized on the surfaces of Au-MNPs, luminol (Method I) and 2′,6′-DiMethylcarbonylphenyl-10-sulfopropylacridinium-9-carboxylate 4′-NHS Ester, (NSP-DMAE-NHS, Method II) were exploited in competitive CLIA for CAP detection in milk using a homemade luminescent measurement system. The sensitivities and limits of detection (LODs) of the two methods were obtained according to the inhibition curves. It indicated that NSP-DMAE-NHS as luminescence reagent (reaction II) was more sensitive and effective than luminol (reaction I). The LOD of reaction II reached 0.008 ng/ml while it was 4 ng/ml in reaction I. Moreover, the linear range of the inhibition curve of the former was wider than that of the latter. Such results indicated that the proposed CLIA stratery employing NSP-DMAE-NHS was more sensitive than other immunoassay method for CAP detection.