Sensitively detecting antigen of SARS-CoV-2 by NIR-II fluorescent nanoparticles

Ruibin Hu; Tao Liao; Yan Ren; Wenming Liu; Rui Ma; Xinyuan Wang; Qihui Lin; Guoxin Wang; Yongye Liang

doi:10.1007/s12274-022-4351-1

Sensitively detecting antigen of SARS-CoV-2 by NIR-II fluorescent nanoparticles

Nano Res. 2022;15(8):7313-7319. doi: 10.1007/s12274-022-4351-1. Epub 2022 May 10.

Authors

Ruibin Hu^#¹, Tao Liao^#², Yan Ren^#³, Wenming Liu², Rui Ma¹, Xinyuan Wang¹, Qihui Lin³, Guoxin Wang², Yongye Liang¹

Affiliations

¹ Department of Materials Science and Engineering, Southern University of Science and Technology of China, Shenzhen, 518055 China.
² WWHS Biotech. Inc., Shenzhen, 518122 China.
³ Joint Laboratory for Infectious Disease Prevention and Control, Hygienic Section of Longhua Center for Disease Control and Prevention, Longhua District, Shenzhen, 518109 China.

^# Contributed equally.

Abstract

Early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is an efficient way to prevent the spread of coronavirus disease 2019 (COVID-19). Detecting SARS-CoV-2 antigen can be rapid and convenient, but it is still challenging to develop highly sensitive methods for effective diagnosis. Herein, a lateral flow assay (LFA) based on fluorescent nanoparticles emitting in the second near-infrared (NIR-II) window is developed for sensitive detection of SARS-CoV-2 antigen. Benefiting from the NIR-II fluorescence with high penetration and low autofluorescence, such NIR-II based LFA allows enhanced signal-to-background ratio, and the limit of detection is down to 0.01 ng·mL^-1 of SARS-CoV-2 antigen. In the clinical swab sample tests, the NIR-II LFA outperforms the colloidal gold LFA with higher overall percent agreement with the polymerase chain reaction test. The clinical samples with low antigen concentrations (∼ 0.015-∼ 0.068 ng·mL^-1) can be successfully detected by the NIR-II LFA, but fail for the colloidal gold LFA. The NIR-II LFA can provide a promising platform for highly sensitive, rapid, and cost-effective method for early diagnosis and mass screening of SARS-CoV-2 infection.

Electronic supplementary material: Supplementary material (the operation procedure and cost of the materials needed of NIR-II lateral flow assays, the dynamic light scattering spectrum of the NIR-II nanoparticles, the components and testing principle, optimization of main parameters pertaining to the LFA performance, the colloidal gold LFA strip, the fluorescence intensity distribution curves and the T/C values of the strips for clinical samples by NIR-II LFA, and results of clinical swab samples detected by colloidal gold LFA) is available in the online version of this article at 10.1007/s12274-022-4351-1.

Keywords: antigen detection; coronavirus disease 2019 (COVID-19); lateral flow assay; severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); the second near-infrared (NIR-II) fluorophores.