Multiple signal amplification chemiluminescence immunoassay for chloramphenicol using functionalized SiO2 nanoparticles as probes and resin beads as carriers

A novel, rapid and convenient competitive immunoassay for ultrasensitive detection of chloramphenicol residues in shrimp and honey was established combined with flow injection chemiluminescence. The carboxylic resin beads were used as solid phase carriers to load with more coating antigen due to their larger specific surface area and good biocompatibility. The surface of the silica dioxide nanoparticles was modified with aldehyde group to combinewith more horseradish peroxidase and the chloramphenicol antibody. Therewas a competitive process between the chloramphenicol in solution and the immobilized coating antigen to combinewith the limited binding site of antibody to formthe immunocomplex. Silica dioxide nanoparticles played an important role in enhancing chemiluminescence signal, because the horseradish peroxidase on SiO2 effectively catalyzed the system of luminol-PIP-H2O2. Under optimal conditions, the chemiluminescence intensity decreased linearly with the logarithmof the chloramphenicol concentration in the range of 0.0001 to 100 ng mL(-1) and the detection limit (3 sigma) was 0.033 pgmL(-1). This immunosensor demonstrated acceptable stability, high specificity and reproducibility. The horseradish peroxidase-silica dioxide nanoparticle-chloramphenicol antibody complex successfully prepared in this article was firstly applied to the detection of chloramphenicol, and had extremely important meanings for the application of nanoparticles and enzymatic catalysis in the field of chemiluminescence. (C) 2019 Published by Elsevier B.V.