Inhibiting Analyte Theft in Surface-Enhanced Raman Spectroscopy Substrates: Subnanomolar Quantitative Drug Detection.
Bart de NijsCloudy CarnegieIstván SzabóDavid-Benjamin GrysRohit ChikkaraddyMarlous KampSteven J BarrowCharlie A ReadmanMarie-Elena KleemannOren A SchermanEdina RostaJeremy J BaumbergPublished in: ACS sensors (2019)
Quantitative applications of surface-enhanced Raman spectroscopy (SERS) often rely on surface partition layers grafted to SERS substrates to collect and trap-solvated analytes that would not otherwise adsorb onto metals. Such binding layers drastically broaden the scope of analytes that can be probed. However, excess binding sites introduced by this partition layer also trap analytes outside the plasmonic "hotspots". We show that by eliminating these binding sites, limits of detection (LODs) can effectively be lowered by more than an order of magnitude. We highlight the effectiveness of this approach by demonstrating quantitative detection of controlled drugs down to subnanomolar concentrations in aqueous media. Such LODs are low enough to screen, for example, urine at clinically relevant levels. These findings provide unique insights into the binding behavior of analytes, which are essential when designing high-performance SERS substrates.
Keyphrases
- raman spectroscopy
- label free
- loop mediated isothermal amplification
- high resolution
- real time pcr
- randomized controlled trial
- systematic review
- sensitive detection
- gold nanoparticles
- emergency department
- high throughput
- signaling pathway
- binding protein
- ionic liquid
- mass spectrometry
- single molecule
- drinking water
- adverse drug
- heavy metals