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Updated: Jan 22, 2026
08:01
Fabrication of Zero Mode Waveguides for High Concentration Single Molecule Microscopy
Published on: May 12, 2020
8.6K
Fluorescence enhancement in an over-etched gold zero-mode waveguide
Optics Express
|June 30, 2019
Summary
Over-etched gold zero-mode waveguides (ZMWs) enhance single-molecule fluorescence detection. Combining undercut and reduced radius in ZMWs significantly improves signal and reduces excitation volume for better performance.
Area of Science:
- Nanophotonics
- Single-molecule spectroscopy
Background:
- Zero-mode waveguides (ZMWs) are crucial for single-molecule detection.
- Optimizing ZMW geometry is essential for enhancing fluorescence signals.
Purpose of the Study:
- To investigate fluorescence enhancement in over-etched gold ZMWs.
- To explore the impact of ZMW radius and undercut on signal performance.
Main Methods:
- Numerical simulations of fluorescence enhancement.
- Fabrication of gold ZMW arrays using focused-ion-beam.
- Fluorescence correlation spectroscopy measurements.
Main Results:
- Over-etching (undercut) enhances fluorescence signals and excitation field uniformity.
- Undercutting increases fluorescence per molecule but slightly expands excitation volume.
- Reducing ZMW radius effectively decreases excitation volume and boosts fluorescence per molecule.
Conclusions:
- Combining undercut and reduced radius in gold ZMWs significantly enhances single-molecule detection performance.
- This approach offers a simple and effective method for improving Au-ZMWs.
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