Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Dec 29;12(1):13.
doi: 10.3390/bios12010013.

Lateral Flow Immunoassay Coupled with Copper Enhancement for Rapid and Sensitive SARS-CoV-2 Nucleocapsid Protein Detection

Tao Peng  1 , Xueshima Jiao  1   2 , Zhanwei Liang  1   2 , Hongwei Zhao  3 , Yang Zhao  1 , Jie Xie  1 , You Jiang  1 , Xiaoping Yu  2 , Xiang Fang  1 , Xinhua Dai  1
Affiliations

Lateral Flow Immunoassay Coupled with Copper Enhancement for Rapid and Sensitive SARS-CoV-2 Nucleocapsid Protein Detection

Tao Peng et al. Biosensors (Basel). .

Abstract

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory coronavirus 2 (SARS-CoV-2) is still raging all over the world. Hence, the rapid and sensitive screening of the suspected population is in high demand. The nucleocapsid protein (NP) of SARS-CoV-2 has been selected as an ideal marker for viral antigen detection. This study describes a lateral flow immunoassay (LFIA) based on colloidal gold nanoparticles for rapid NP antigen detection, in which sensitivity was improved through copper deposition-induced signal amplification. The detection sensitivity of the developed LFIA for NP antigen detection (using certified reference materials) under the optimized parameters was 0.01 μg/mL and was promoted by three orders of magnitude to 10 pg/mL after copper deposition signal amplification. The LFIA coupled with the copper enhancement technique has many merits such as low cost, high efficiency, and high sensitivity. It provides an effective approach to the rapid screening, diagnosis, and monitoring of the suspected population in the COVID-19 outbreak.

Keywords: SARS-CoV-2; copper deposition; nucleocapsid protein; signal amplification.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
The diagram of GCNP-based LFIA coupled with copper deposition-introduced signal amplification for NP antigen detection. (A) Elements of the developed NP antigen detection system. (B) Results of antigen detection and signal amplification.
Figure 2
Figure 2
Comparison of the detection sensitivity before and after signal amplifying introduced by copper deposition.
Figure 3
Figure 3
Optimization of the amount of 0.2 M K2CO3 solution used (A), antibody I used in the detection probes (B), and goat anti-mouse IgG on the control line (C). The positive sample was buffer spiked with 0.1 μg/mL of the NP antigen.
Figure 4
Figure 4
Optimization of the antibody II amount on the test line (A) and the width of LFIA test strip (B).
Figure 5
Figure 5
Simple device for copper deposition signal amplification (A,B); detection of NP antigen standard solutions before and after signal amplification (C).
See this image and copyright information in PMC

References

    1. Xu W.Z., Li J., He X.Y., Zhang C.Q., Li C.R., Li Y., Cheng S.H., Zhang P.A. The diagnostic value of joint detection of serum IgM and IgG antibodies to 2019-nCoV in 2019-nCoV infection. Chin. J. Lab. Med. 2020;43:E01–E06.
    1. Ong D.S.Y., de Man S.J., Lindeboom F.A., Koeleman J.G.M. Comparison of diagnostic accuracies of rapid serological tests and ELISA to molecular diagnostics in patients with suspected COVID-19 presenting to the hospital. Clin. Microbiol. Infect. 2020;26:1094.e7–1094.e10. doi: 10.1016/j.cmi.2020.05.028. - DOI - PMC - PubMed
    1. Wang C.W., Yang X.S., Gu B., Liu H.F., Zhou Z.H., Shi L.L., Cheng X.D., Wang S.Q. Sensitive and Simultaneous Detection of SARS-CoV-2-Specific IgM/IgG Using Lateral Flow Immunoassay Based on Dual-Mode Quantum Dot Nanobeads. Anal. Chem. 2020;92:15542–15549. doi: 10.1021/acs.analchem.0c03484. - DOI - PubMed
    1. Seo G., Lee G., Kim M.J., Baek S.-H., Choi M., Ku K.B., Lee C.-S., Jun S., Park D., Kim H.G., et al. Rapid Detection of COVID-19 Causative Virus (SARS-CoV-2) in Human Nasopharyngeal Swab Specimens Using Field-Effect Transistor-Based Biosensor. ACS Nano. 2020;14:5135–5142. doi: 10.1021/acsnano.0c02823. - DOI - PubMed
    1. Cui J., Li F., Shi Z.L. Origin and evolution of pathogenic coronaviruses. Nat. Rev. Microbiol. 2019;17:181–192. doi: 10.1038/s41579-018-0118-9. - DOI - PMC - PubMed