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

Authors

Eunice Ebbah, Illinois State University
Anthony Amissah, Illinois State University
Jun-Hyun Kim, Illinois State UniversityFollow
Jeremy D. Driskell, Illinois State UniversityFollow

Document Type

Article

Publication Date

2024

Publication Title

ACS Sensors

Keywords

vertical flow, immunoassay, plasmonic coupling, surface-enhanced Raman spectroscopy, point-of-care, core−satellite

Abstract

Here, we describe a SERS-based vertical flow assay as a platform technology suitable for point-of-care (POC) diagnostic testing. A capture substrate is constructed from filter paper embedded with spherical gold nanoparticles (AuNPs) and functionalized with an appropriate capture antibody. The capture substrate is loaded into a filtration device and connected to a syringe to rapidly and repeatedly pass the sample through the sensor for efficient antigen binding. The antigen is then labeled with a SERS-active detection probe. We show that only a few Raman reporter molecules, exclusively located adjacent to the plasmonic capture substrate, generate detectible signals. To maximize the signal from underutilized Raman reporter molecules, we employ a secondary signal enhancing probe that undergoes antibody-directed assembly to form plasmonic core–satellites. This facile enhancement step provides a 3.5-fold increase in the signal and a detection limit of 0.23 ng/mL (1.6 pM) for human IgG. This work highlights the potential to rationally design plasmonic architectures using widely available and reproducible spherical AuNPs to achieve large SERS enhancements for highly sensitive POC diagnostics.

Funding Source

This work was supported by the National Science Foundation (Award #CHE-2203740) and the National Institutes of Health (Award #1R15GM146167-01). The FESEM multiuser facility was acquired with the support from the Division of Material Research (DMR), National Science Foundation (Award #DMR-2116612). This article was published Open Access thanks to a transformative agreement between Milner Library and ACS.

DOI

10.1021/acssensors.4c01052

Comments

First published in ACS Sensors (2024). https://doi.org/10.1021/acssensors.4c01052.

This open access publication is licensed under CC-BY 4.0.

Recommended Citation

Eunice Ebbah, Anthony Amissah, Jun-Hyun Kim, and Jeremy D. Driskell, "Antibody-Driven Assembly of Plasmonic Core–Satellites to Increase the Sensitivity of a SERS Vertical Flow Immunoassay," ACS Sensors (2024). https://doi.org/10.1021/acssensors.4c01052.