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Updated: May 8, 2026
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Plasmonic Trapping and Release of Nanoparticles in a Monitoring Environment
Published on: April 4, 2017
Surface-Selective Molecular Binding and Replacement Selectivity in Plasmonic Nanocavities.
Eric S A Goerlitzer1, Zijia Wu1, Aidan Brzakalik1
1Nanophotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0US, United Kingdom.
The Journal of Physical Chemistry Letters
|May 7, 2026
Summary
Researchers optically tracked molecular self-assembled monolayers (SAMs) in nanocavities. They discovered replacement thiols attach to nanoparticles, offering new ways to control nanoscale chemical assembly.
Area of Science:
- Nanoscience and nanotechnology
- Surface chemistry
- Plasmonics
Background:
- Molecular self-assembled monolayers (SAMs) are crucial in nanoscience for applications like sensing and molecular electronics.
- Thiol binding to coinage metals typically forms robust molecular layers on planar surfaces.
- Understanding SAM behavior at the nanoscale, especially in confined environments, remains limited.
Purpose of the Study:
- To investigate the replacement dynamics of thiol SAMs within nanocavities under plasmonic confinement.
- To elucidate the mechanism of thiol SAM replacement when nanoparticles are introduced onto the SAM.
- To explore methods for controlling these replacement dynamics for tailored nanostructures.
Main Methods:
- Utilizing strong plasmonic confinement for optical tracking of SAM replacement.
- Employing a range of model thiol molecules to study replacement mechanisms.
- Investigating the role of dithiols in preventing or controlling thiol exchange.
Main Results:
- An unexpected mechanism for thiol SAM replacement was observed in nanocavities when nanoparticles were added.
- Replacement thiols preferentially attach to the overlying nanoparticle and rotate into the nanogap.
- Dithiols were found to effectively prevent this replacement by stabilizing metal atoms.
Conclusions:
- The study reveals a novel mechanism for thiol SAM replacement driven by nanoparticle interaction in confined plasmonic systems.
- This mechanism provides a pathway for precise spatial control over molecular assembly at the nanoscale.
- The findings enable the creation of asymmetric molecular architectures and post-functionalization of plasmonic nanostructures.
