| Because of its rapid detection method,antigen detection has become a major means of auxiliary diagnosis of COVID-19,and how to build a more sensitive antigen detection method has become a hot topic of experts,scholars and enterprises.In this paper,a fluorescence immunochromatographic detection method for novel coronavirus 2019-n COV based on quantum dot microsphere labeling was established,and fluorescence immunochromatographic test strips were developed to conduct practical validation of samples and methodological comparison tests.The results of this study provide ideas and means for rapid and sensitive detection of other infectious diseases.In this paper,we prepared quantum dot microspheres by membrane emulsification technology,and conjugated monoclonal labeled antibody to novel coronavirus antigen and fluorescent microspheres to form fluorescent markers through EDC and NHS.By combining immunochromatography with luminescence technology,the novel coronavirus antigen trapping monoclonal antibody was coated on the NC membrane,and a sandwich immunological quantitative detection method was studied and established between two monoclonal antibodies and the new coronavirus antigen target object in the sample,and a quantitative detection strip was prepared.A dry immunofluorescence analyzer was used for the quantitative detection and analysis of novel coronavirus samples.The results showed that the quantum-dot microspheres immunochromatographic strips developed in this paper could more sensitively detect three types of COVID-19 samples,including N protein recombinant antigen,Delta inactivated disease venom,and Gamma inactivated disease venom.The linear range of N protein recombinant antigen was 1-10000 pg/m L,and the sensitivity was 1 pg/m L.The linear range of Delta inactivated disease venom was 10-1000 pg/m L and the sensitivity was 10pg/m L.The linear range of Gamma inactivated disease venom is 2-2000 pg/m L with a sensitivity of 2 pg/m L.Repeatability and stability CV < 10;There is no cross-reaction with other respiratory viruses.The sensitivity analysis of the quantum dot microspheres immunochromatography method in this study was compared with the colloidal gold chromatography strip method.The results showed that the quantum dot microspheres fluorescence immunochromatography strip was 10 times higher than colloidal gold in the detection of N protein recombinant antigen,3 times higher than the detection of Dleta inactivated disease venom,and 100 times higher than the detection of Gamma inactivated disease venom.These results indicate that the quantum dot microsphere immunochromatography has higher sensitivity than the traditional colloidal gold immunoside chromatography.The research results of this paper provide a new method for the rapid detection of novel coronavirus 2019-n COV,and provide experimental technology and application development support for the subsequent development of in vitro diagnostic products. |
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