Abstract
We report a dual-readout, AuNP-based sandwich immunoassay for the device-free colorimetric and sensitive scanometric detection of disease biomarkers. An AuNP-antibody conjugate serves as a signal transduction and amplification agent by promoting the reduction and deposition of either platinum or gold onto its surface, generating corresponding colorimetric or light scattering (scanometric) signals, respectively. We apply the Pt-based colorimetric readout of this assay to the discovery of a novel monoclonal antibody (mAb) sandwich pair for the detection of an anthrax protective antigen (PA83). The identified antibody pair detects PA83 down to 1 nM in phosphate-buffered saline and 5 nM in human serum, which are physiologically relevant concentrations. Reducing gold rather than platinum onto the mAb-AuNP sandwich enables scanometric detection of subpicomolar PA83 concentrations, over 3 orders of magnitude more sensitive than the colorimetric readout.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 7845-7851 |
| Number of pages | 7 |
| Journal | Analytical Chemistry |
| Volume | 92 |
| Issue number | 11 |
| DOIs | |
| State | Published - Jun 2 2020 |
Funding
This material is based on research sponsored by Air Force Research Laboratory agreement FA8650-15-2-5518; the Office of the Director of National Intelligence, Intelligence Advanced Research Projects Activity, via Federal Bureau of Investigation Contract DJF-15-1200-K-0001730; the Air Force Office of Scientific Research Awards FA9550-18-1-0493 and FA9550-16-1-0150; the NTU-NU Institute for NanoMedicine located at the International Institute for Nanotechnology, Northwestern University, US, and the Nanyang Technological University, Singapore; and the National Cancer Institute of the National Institutes of Health Awards U54CA199091 and U54CA151880. Research reported was also supported by the following training programs: The Cellular and Molecular Basis of Disease Training Program funded by the National Institutes of Health, Institute of General Medical Sciences Award T32GM008061, and the Chemistry of Life Processes Training Program in conjunction with National Institute of General Medical Sciences Award T32GM105538. The content is solely the responsibility of the authors and does not necessarily represent the official views of the sponsors or the US Government.
ASJC Scopus subject areas
- Analytical Chemistry
