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Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing
Published on: March 13, 2013
Surface plasmon resonance optical cavity enhanced refractive index sensing.
A Giorgini1, S Avino, P Malara
1Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica, via Campi Flegrei, 34—Comprensorio A. Olivetti, 80078 Pozzuoli, Naples, Italy.
Optics Letters
|June 1, 2013
Summary
This study introduces a new surface plasmon resonance (SPR) sensor using direct time-domain measurements. This method achieves high resolution for refractive index sensing without intensity or spectroscopic analysis.
Area of Science:
- Photonics and optical sensing
- Nanotechnology and materials science
Background:
- Surface plasmon resonance (SPR) is a label-free optical technique widely used for detecting molecular interactions and measuring refractive index changes.
- Conventional SPR sensing often relies on intensity measurements or spectroscopic analysis, which can be susceptible to light source fluctuations and environmental noise.
Purpose of the Study:
- To develop and demonstrate a novel SPR refractive index sensing method based on direct time-domain measurements.
- To achieve high resolution and robustness against light intensity fluctuations in SPR sensing.
Main Methods:
- An optical resonator was integrated with an SPR sensor.
- Photon lifetime within the resonator was measured as a function of optical loss induced by refractive index variations.
- Direct time-domain measurements were employed, avoiding spectroscopic analysis or direct intensity measurements.
Main Results:
- The developed method demonstrated high resolution, with a refractive index resolution of approximately 10(-5) RIU (Refractive Index Units) achieved in a proof-of-concept experiment.
- The time-domain approach proved to be practically immune to light intensity fluctuations, ensuring measurement stability.
- Extrapolation suggests potential for resolutions better than 10(-7) RIU/√Hz with long-term averaging.
Conclusions:
- Direct time-domain measurements offer a robust and high-resolution alternative for SPR refractive index sensing.
- The method's immunity to intensity fluctuations and potential for high resolution make it suitable for sensitive biosensing and chemical detection applications.
