Antibody-Driven Assembly of Plasmonic Core-Satellites to Increase the Sensitivity of a SERS Vertical Flow Immunoassay.
Eunice EbbahAnthony AmissahJun-Hyun KimJeremy D DriskellPublished in: ACS sensors (2024)
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.
Keyphrases
- label free
- gold nanoparticles
- quantum dots
- sensitive detection
- crispr cas
- high throughput
- endothelial cells
- living cells
- reduced graphene oxide
- raman spectroscopy
- particulate matter
- amino acid
- wastewater treatment
- air pollution
- single molecule
- computed tomography
- energy transfer
- heavy metals
- highly efficient
- high resolution
- transcription factor
- cancer therapy
- binding protein
- single cell