%0 Journal Article
%T A nanogap-enhanced SERS nanotag-based lateral flow assay for ultrasensitive and simultaneous monitoring of SARS-CoV-2 S and NP antigens.
%A Liu X
%A Yang X
%A Wang C
%A Liu Q
%A Ding Y
%A Xu S
%A Wang G
%A Xiao R
%J Mikrochim Acta
%V 191
%N 2
%D 2024 01 18
%M 38236334
%F 6.408
%R 10.1007/s00604-023-06126-x
%X A lateral flow assay (LFA) strip based on dual 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB)-encoded satellite Fe3O4@Au (Mag@Au) SERS tags with nanogap is reported for  ultrasensitive and simultaneous diagnosis of two SARS-CoV-2 functional proteins. Composed of Fe3O4 core, satellite gold shell with nanogaps, and double-layer DTNB, the Mag@Au nanoparticles with an average size of 238 nm were designed as multifunctional tags to efficiently enrich the target SARS-CoV-2 protein from complex samples, significantly enhancing the SERS signal of the LFA strip and provide quantitative SERS detection of analyte on test lines. The developed dual DTNB-encoded satellite Mag@Au-based LFA allowed simultaneous quantification of spike (S) protein and nucleocapsid (NP) protein with detection limits of 23 pg mL-1 and 2 pg mL-1, respectively, lower than commercial ELISA kits and reported SERS-LFA detection system-based Au NPs and Fe3O4@3 nm Au MNPs. This magnetic SERS-LFA also showed high performance of multi-variant strain detection and further distinguished clinical samples of Omicron variant infection, demonstrating the potential of in situ detection of respiratory virus diseases.