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10:40
High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Surface plasmon-enhanced and quenched two-photon excited fluorescence
Chun-Yu Lin1, Kuo-Chih Chiu, Chia-Yuan Chang
1Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan.
Optics Express
|July 1, 2010
Summary
Surface plasmons enhance two-photon excited fluorescence microscopy signals by up to 30-fold. This study optimizes the surface plasmon-total internal reflection fluorescence (SP-TIRF) configuration for improved imaging and fluorophore stability.
Area of Science:
- Optics and Photonics
- Biophysics
- Materials Science
Background:
- Two-photon excited fluorescence (TPEF) is a powerful imaging technique.
- Surface plasmons (SPs) can enhance fluorescence through local electromagnetic field effects.
- Controlling SP-metal interactions is key to optimizing TPEF signals.
Purpose of the Study:
- To theoretically and experimentally investigate the enhancement and quenching of TPEF via surface plasmons.
- To analyze the influence of dielectric spacer thickness on fluorescence properties.
- To develop an optimized SP-TIRF configuration for enhanced imaging and photostability.
Main Methods:
- Theoretical analysis using Fresnel equations and classical dipole radiation modeling.
- Experimental implementation of two-photon excited total internal reflection fluorescence (TIRF) microscopy.
- Utilized time-correlated single photon counting for lifetime and photostability measurements.
Main Results:
- Theoretical predictions for electric field enhancement, quantum yield, and emission coupling were consistent with experimental data.
- Maximum fluorescence enhancement factor of up to 30-fold was achieved in the SP-TIRF configuration with an optimized SiO(2) spacer.
- A 10 nm SiO(2) spacer provided a balance between fluorescence enhancement and improved fluorophore photostability.
Conclusions:
- Surface plasmon excitation via total internal reflection significantly enhances two-photon fluorescence.
- The SP-TIRF configuration offers a viable method for improving imaging sensitivity and reducing photobleaching.
- Optimizing spacer thickness is crucial for maximizing fluorescence enhancement while maintaining fluorophore integrity.
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