Abstract
Lateral flow immunoassay(LFIA)has become popular in laboratories,at-home testing,and medical diag-nostics due to its minimal cost and user-friendliness.Nevertheless,conventional test strips based on col-loidal gold can only obtain qualitative or semi-quantitative results with low sensitivity.In this work,Au-Fe3O4 dumbbell-like nanoparticles were synthesized and used as the LFIA labelling marker for highly sen-sitive colorimetric-photothermal dual-mode detection of SARS-CoV-2 spike(S)protein.The unique dumb-bell structure of Au-Fe3O4 NPs makes it possible to combine the best features of both Au NPs and Fe3O4 NPs.The increased surface area of these NPs enhances their LSPR effect and photothermal effect,which achieves signal amplification to increase sensitivity.The Au-Fe3O4 NPs modified with S protein antibody could identify S protein in samples,which were recognized and accumulated on T-line by another an-tibody,generating color band for qualitative colorimetric detection.The T-line was irradiated by laser to obtain temperature change for quantitative detection of photothermal.In optimized conditions,the detec-tion limit was 1.22 pg/mL,three orders of magnitude more sensitive than colorimetric detection.Finally,the approach was performed on SARS-CoV-2 pseudovirus samples and outperformed traditional colloidal gold strips.This LFIA platform exhibits significant promise for practical implementation,as it can satisfy the need for low-cost,high-sensitivity,and home-based quantitative detection for respiratory infectious diseases.
基金项目
Natural Scientific Foundation of Shandong(ZR2023MC039)
Natural Scientific Foundation of Shandong(ZR2022JQ07)
National Natural Science Foundation of China(21876206)
Fundamental Research Funds for the Central Universities(21CX06014A)
Taishan Scholarship of Shandong Province(tsqn202211080)
NETL
NSTL
万方数据