High-throughput Light-induced Immunoassay under One-minute Antibody-coating with Energy Saving Nanoparticle-imprinted Substrate

The efficient detection of harmful viruses and protein biomarkers is critical for public health. However, the sensitivity of conventional antigen test kits is relatively low for early diagnosis, and laboratory immunoassays require complex pretreatment processes overnight. If target nanomaterials could be remotely guided to the detection site, simpler and faster methods would be developed. Here, we reveal that nanoparticles modified with spike proteins of SARS-CoV-2 can be selectively detected with 1/100 of virus concentration in saliva via a two-step optical condensation using our nanoparticle-imprinted plasmonic substrate (NPI-PS), where anti-spike-protein antibody was coated on NPI-PS over submillimeter area within one minute. NPI-PS exhibits high-performance optical condensation with high photothermal properties even under noninvasive milliwatt-class laser irradiation, enabling quantitative measurements of nanoparticles ranging from 10 ⁶ –10 ¹⁰ particles/mL within a few minutes. These findings support an innovative strategy to mitigate pandemic threats and various diseases through the high-throughput detection of various protein biomarkers.