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Updated: Jun 7, 2025
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Conducting Multiple Imaging Modes with One Fluorescence Microscope
Published on: October 28, 2018
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Fluorescence from a single-molecule probe directly attached to a plasmonic STM tip
Niklas Friedrich1,2, Anna Rosławska3, Xabier Arrieta4
1CIC nanoGUNE-BRTA, Donostia-San Sebastián, Spain. niklas.friedrich@ur.de.
Nature Communications
|November 10, 2024
Summary
This study introduces fluorescent molecular probes for scanning tunneling microscopy (STM). Researchers achieved single-molecule fluorescence imaging, enabling new atomic-scale investigations.
Area of Science:
- Nanotechnology
- Surface Science
- Spectroscopy
Background:
- Scanning tunneling microscopy (STM) enables atomic-scale analysis of conductive materials.
- Single-molecule tip functionalization is established, but fluorescent probes were previously unavailable for STM.
Purpose of the Study:
- To develop and demonstrate the use of fluorescent molecular probes functionalized on an STM tip.
- To investigate the optical properties of single molecules in nanoscale junctions.
Main Methods:
- Functionalizing an STM tip with a single fluorescent molecule.
- Scanning the functionalized tip over a plasmonic substrate.
- Recording light emission generated by tunneling current through the tip-molecule-substrate junction.
Main Results:
- Generated narrow-line light emission corresponding to the fluorescence of the excited molecular anion.
- Demonstrated that emission peak width probes exciton-plasmon coupling strength.
- Showed that photon energy depends on molecule-environment interactions.
Conclusions:
- Successfully integrated fluorescent molecular probes into STM for nanoscale imaging.
- Established a method to probe exciton-plasmon coupling and molecular interactions via light emission.
- Theoretically explained how radiative emission is sustained despite direct contact with the metallic tip.
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