The Synthesis of a Two-Photon Fluorescence Labelling Probe and its Immunochromatographic Strip for Rapid Diagnosis of COVID-19

Chibao Huang,Zairong Wei,Shuai Kang,Fuxun Yu

doi:10.1071/ch20344

Abstract

A two-photon fluorescence labelling probe (LP) was synthesised, and LP-Ag was obtained by LP labelling the N-protein antigen (Ag) of COVID-19. LP-Ag was made into an immunochromatographic strip. When a blood sample was added to the sample hole of the test card, it would move forward along the nitrocellulose (NC) film. If the sample contained IgM, the IgM bound to LP-Ag and formed an M line with the coated mouse anti-human IgM antibody, giving a positive response to the presence of IgM of COVID-19. The sensitivity, specificity, and accuracy of the immunochromatographic strip based on the LP was compared with those of the nucleic acid detection method and the colloidal gold method, proving it to be much simpler than the nucleic acid detection method, which can greatly shorten the detection period, and to be much more stable than the colloidal gold method, which can overcome uncertainty. LP-Ag can be used to image lung tissue with COVID-19 by two-photon fluorescence microscopy (TFM).

Highlights

The new type of coronavirus (COVID-19) was the culprit of the viral pneumonia in 2019, and belongs to the family of RNA viruses
The detection of COVID-19 is limited to nucleic acid detection (RT-positive coincidence rate (PCR), reverse transcription–polymerase chain reaction), and the steps are so many, the operation is cumbersome, and the detection period long; and the detection results are disturbed by many factors
The acedan derivative labelling probe (LP) was obtained in 52 % yield by the reaction of N-hydroxysuccinimide (NHS) with 5 in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) (Scheme 1)

Summary

Introduction

The new type of coronavirus (COVID-19) was the culprit of the viral pneumonia in 2019, and belongs to the family of RNA viruses. There are three major challenges of COVID-19: first is the contagion to wild animals, pets, herds, and humans; second is the one-step replication of the coronavirus RNA, which is similar to human mRNA, so it can be translated and synthesised directly, eliminating the RNA-DNAmRNA transcription process; third, during the process of replication, the mutation of the virus RNA is fast, and its activity to repair the wrong enzyme is very low, so it is easy for the virus to mutate, whereas a vaccine is to be developed according to the fixed gene or protein of a virus, and an RNA virus vaccine is more difficult to develop. An immuno two-photon fluorescent probe based on the N-protein antigen was developed for rapid virus detection, providing a technical guarantee for early diagnosis, early isolation, and early treatment of latent virus

Methods

Results

Conclusion