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Particle sensing with confined optical field enhanced fluorescence emission (Cofefe)
Optics Express
|May 27, 2018
Summary
A novel optical sensor, confined optical field enhanced fluorescence emission (Cofefe), detects nanoparticles near gold surfaces. This label-free method uses unique optical signals for sensitive nanoscopic particle detection.
Area of Science:
- Nanotechnology
- Optical Sensing
- Surface Science
Background:
- Existing optical sensing methods like SPR microscopy have limitations.
- There is a need for sensitive, label-free detection of nanoscopic particles.
Purpose of the Study:
- To develop and characterize a new optical sensor for detecting nanoscopic particle binding and dissociation.
- To introduce a novel optical read-out mechanism based on confined optical fields.
Main Methods:
- Development of the confined optical field enhanced fluorescence emission (Cofefe) sensor.
- Utilizing pulsed surface plasmon polariton fields at a gold/liquid interface.
- Detecting fluorescence emission from two-photon absorption induced by confined near-fields.
Main Results:
- The Cofefe sensor successfully detected gold and silicon nanoparticles, polymer nanospheres, and lipid droplets.
- Label-free detection was achieved with low illumination power (< 10 μW/μm²).
- Bound nanoparticles appeared as bright spots against a dark background.
Conclusions:
- The Cofefe sensor offers a sensitive and label-free method for nanoscopic particle detection.
- This technology provides a new optical signature for binding events.
- The sensor demonstrates versatility in detecting various types of nanoparticles and droplets.
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