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Monitoring Conformational Dynamics of Single Unmodified Proteins using Plasmonic Nanotweezers
Published on: March 21, 2025
Attomolar protein detection using in-hole surface plasmon resonance
Jacqueline Ferreira1, Marcos J L Santos, Mohammad M Rahman
1Department of Chemistry, University of Victoria, P.O. Box 3065, V8W 3V6, Victoria, BC, Canada.
Journal of the American Chemical Society
|January 15, 2009
Summary
This study introduces an improved nanohole surface plasmon resonance sensing method for detecting molecules. The new technique enhances sensitivity and lowers detection limits for biological and organic molecule binding.
Area of Science:
- Nanotechnology
- Plasmonics
- Biosensing
Background:
- Surface plasmon resonance (SPR) is a powerful label-free optical sensing technique.
- Previous nanohole array SPR methods detected binding on both hole interiors and exterior surfaces.
- This limited specificity and potentially reduced sensitivity.
Purpose of the Study:
- To develop a more efficient and specific in-hole nanohole SPR sensing scheme.
- To improve sensitivity and lower the detection limit for molecular binding events.
- To differentiate binding events occurring inside nanoholes from those on external surfaces.
Main Methods:
- Fabrication of periodic nanohole arrays through SiO(x) and gold thin films.
- Utilizing resonant surface plasmon enhanced transmission through the nanoholes.
- Detecting molecular binding specifically within the nanoholes.
Main Results:
- Demonstrated an "in-hole" nanohole SPR sensing scheme.
- Achieved higher sensitivity (650 nm/RIU) compared to previous methods.
- Estimated detection of three attomoles of proteins, indicating a lower detection limit.
Conclusions:
- The "in-hole" nanohole SPR sensing approach offers enhanced specificity and efficiency.
- Resonant surface plasmon enhanced transmission is key to improved performance.
- This method shows significant potential for sensitive detection of organic and biological molecules.
