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Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation
Published on: September 27, 2011
A microsphere coupler for a nanowire waveguide plasmonic probe for molecular imaging.
Alex Heltzel1, Li Shi, John R Howell
1PC Krause and Associates, West Lafayette, IN 47906, USA. heltzel@pcka.com
Nanotechnology
|December 16, 2010
Summary
A silica microsphere enhances light coupling to a gold nanoparticle tip for improved near-field imaging. This method boosts signal-to-noise ratio for single molecule detection and cell membrane analysis.
Area of Science:
- Optics and Photonics
- Nanotechnology
- Biophysics
Background:
- Mie theory predicts highly forward light scattering by silica microspheres.
- Near-field imaging requires efficient light coupling to nanoscale probes.
- Gold nanoparticles (Au NPs) are crucial for plasmonic enhancement in imaging.
Purpose of the Study:
- To investigate the use of silica microspheres for coupling light into ZnO nanowires with Au NP tips.
- To optimize near-field imaging of single molecules and cell membranes.
- To enhance the signal-to-noise ratio (SNR) in plasmonic imaging.
Main Methods:
- Finite-difference time-domain (FDTD) simulations were employed.
- Simulations examined light coupling efficiency from silica microspheres to Au NP tips.
- The influence of excitation incident angle on plasmonic coupling was analyzed.
Main Results:
- Plasmonic coupling at the Au tip is sensitive to the excitation's incident angle.
- Silica microsphere pre-conditioning amplifies light coupling to the Au NP tip.
- Background energy levels were reduced, significantly boosting the SNR.
Conclusions:
- Silica microspheres effectively enhance light coupling for near-field imaging applications.
- The proposed system improves signal detection for single molecules and labeled cell membranes.
- Optimizing incident angle and using microsphere pre-conditioning are key for high-SNR imaging.
