ABSTRACT
The emergence and development of low-cost and high-efficiency nanozymes are promising to replace natural enzymes promoting the application of chemiluminescence immunoassays. Herein, a rapid and highly sensitive flow injection chemiluminescence immunoassay based on cobalt hydroxide (Co(OH)2) nanozyme was established to detect enrofloxacin (ENR) residues in food. In this system, Co(OH)2 nanosheets act as nanozymes to catalyze and amplify the chemiluminescence signal of the luminol-PIP-H2O2 system, as well as a carrier for immobilizing antibodies to form stable immunoprobes. In addition, carboxyl resin beads with good stability and biocompatibility were used as the base of the immunosensor to carry more coating antigens, based on the principle of competitive immunity and to achieve the rapid detection of ENR. Under optimal conditions, the linear working range is 0.0001 ~ 1000 ng/mL, and the limit of detection (LOD) is 0.041 pg/mL (S/N = 3). The method has been successfully applied to the analysis of aquatic products and poultry food. A non-enzyme immunosensor using Co(OH)2 nanosheets as antibody-conjugated carriers and peroxidase mimics for catalytic amplification of the chemiluminescence signal of luminol and using carboxyl resin beads as platform was designed to detect ENR residues in food.
Subject(s)
Anti-Bacterial Agents/analysis , Cobalt/chemistry , Enrofloxacin/analysis , Hydroxides/chemistry , Immunoassay/methods , Nanostructures/chemistry , Animals , Anti-Bacterial Agents/immunology , Antibodies, Immobilized/immunology , Catalysis , Chickens , Ducks , Enrofloxacin/immunology , Food Contamination/analysis , Hydrogen Peroxide/chemistry , Iodobenzenes/chemistry , Limit of Detection , Luminescence , Luminescent Agents/chemistry , Luminescent Measurements , Luminol/chemistry , Seafood/analysisABSTRACT
The use of the heterologous competitive strategy has become a vital method to improve the sensitivity of ELISA. In this work, we prepared an anti-enrofloxacin (ENR) mAb with ENR-bovine serum albumin (BSA) as immunogen. The molecular descriptors of quinolones were then used to screen heterologous coating antigens for the detection of ENR based on an ensemble learning method to improve the sensitivity of the ELISA. Results indicated that 6 of the 7 selected heterologous competitive antigens could enhance the sensitivity of ELISA. The ELISA sensitivity for the detection of ENR with sarafloxacin-BSA as heterologous coating antigen was improved 10-fold (in PBS) and 6-fold (in milk) compared with that with ENR-BSA as homologous antigen. The strategy can effectively screen suitable heterologous competitive antigens to improve the sensitivity of ELISA, followed by preparation of mAb with no additional modification to the corresponding immunogen.
