An immunochromatographic method for SARS-CoV-2 based on the assistance of internal reference protein / 军事医学

ABSTRACT

Objective To monitor the validity of the sample process flow and to improve the detection accuracy of a SARS-CoV-2 antigen by introducing internal reference into SARS-CoV-2 fluorescent lateral flow assay.Methods Silica-core double-layer quantum dots(SiO2-DQD)microspheres were prepared using a polyethyleneimine(PEI)-mediated self-assembly method before being separately conjugated with an internal reference detection antibody and SARS-CoV-2 antibody.Their capture antibodies were plotted on two test lines of the nitrocellulose membrane.Based on double-antibody sandwich detection principles,an internal reference-assisted fluorescent lateral flow assay for SARS-CoV-2 antigen was established.Results According to the readout fluorescent signals,the detection limit of the method for the SARS-CoV-2 antigen reached 0.01 ng/ml with a validated sample process,suggesting its good specificity and stability.Conclusion In this study,a rapid internal reference-integrated fluorescent lateral flow assay for SARS-CoV-2 has been established,which provides control reference for the analysis workflow so that the false-negative rate of the test results can be reduced.