SERS-based immunoassay on a plasmonic syringe filter for improved sampling and labeling efficiency of biomarkers

Abstract

Rapid, sensitive, and quantitative detection of biomarkers is needed for early diagnosis of disease and surveillance of infectious outbreaks.

Plasmonic Annular Nanotrenches with 1 nm Nanogaps for Detection of SARS-CoV-2 Using SERS-Based Immunoassay

“…Immunoassays have been widely employed to detect and quantify target analytes in biological samples by leveraging specific immunochemical reactions between antibodies and antigens . When combined with SERS, immunoassay platforms have demonstrated improved performance metrics such as sensitivity, selectivity, and reproducibility. − In our study, we utilized SERS-based immunoassay as a proof-of-concept for detecting SARS-CoV-2 spike glycoproteins, which is a biomarker for diagnosing SARS-CoV-2 infection, as described in Figure a. The substrates were Au-coated Si wafers modified with capture antibodies (anti SARS-CoV-2 spike glycoprotein antibody and rabbit polyclonal antibody).…”

Antibody-Driven Assembly of Plasmonic Core–Satellites to Increase the Sensitivity of a SERS Vertical Flow Immunoassay

“… Unlike lateral flow assays, vertical flow assays facilitate rapid immunoreaction between the analyte and label on the capture substrate, where the results are immediately available without the need for assay development time. In addition, the sequential assay procedure prevents the hook effect and provides quantitatively accurate analysis. , Sensitive detection was achieved from the Raman report molecules located in the gap between the plasmonic detection probe and underlying plasmonic paper (Figure A) . The majority of reporter molecules were not fully located in the “hot spot” and therefore contributed minimally to the detected signal.…”

“…Rationally designed SERS assays that leverage plasmonic coupling can achieve large enhancement factors for high sensitivity detection, while capitalizing on the attributes of spherical AuNP. , Recently, we developed a SERS-based vertical flow assay using antibody-functionalized plasmonic paper as a capture substrate to facilitate plasmonic coupling with the detection probe (Figure S1). Unlike lateral flow assays, vertical flow assays facilitate rapid immunoreaction between the analyte and label on the capture substrate, where the results are immediately available without the need for assay development time. In addition, the sequential assay procedure prevents the hook effect and provides quantitatively accurate analysis. , Sensitive detection was achieved from the Raman report molecules located in the gap between the plasmonic detection probe and underlying plasmonic paper (Figure A) .…”

“… 17 , 18 Recently, we developed a SERS-based vertical flow assay using antibody-functionalized plasmonic paper as a capture substrate to facilitate plasmonic coupling with the detection probe ( Figure S1 ). 19 Unlike lateral flow assays, vertical flow assays facilitate rapid immunoreaction between the analyte and label on the capture substrate, where the results are immediately available without the need for assay development time. In addition, the sequential assay procedure prevents the hook effect and provides quantitatively accurate analysis.…”

“… 20 , 21 Sensitive detection was achieved from the Raman report molecules located in the gap between the plasmonic detection probe and underlying plasmonic paper ( Figure 1 A). 19 The majority of reporter molecules were not fully located in the “hot spot” and therefore contributed minimally to the detected signal. Thus, there is an opportunity to make more efficient use of Raman reporter molecules.…”