Stand-Off Biodetection with Free-Space Coupled Asymmetric Microsphere Cavities
| Autor: | Martin D. Baaske, Zachary S. Ballard, Frank Vollmer |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Optical fiber
Materials science Microfluidics Physics::Optics lcsh:Chemical technology Biochemistry Article Analytical Chemistry law.invention Resonator Optics label-free detection law lcsh:TP1-1185 Electrical and Electronic Engineering Instrumentation Quantum tunnelling Coupling business.industry Optical Imaging Whispering Gallery Mode (WGM) biosensors Resonance free-space coupling protein adsorption Microspheres Atomic and Molecular Physics and Optics Refractometry Light emission biosensing Whispering-gallery wave business asymmetric resonant cavities |
| Zdroj: | Sensors Volume 15 Issue 4 Pages 8968-8980 Sensors (Basel, Switzerland) Sensors, Vol 15, Iss 4, Pp 8968-8980 (2015) |
| ISSN: | 1424-8220 |
| DOI: | 10.3390/s150408968 |
| Popis: | Asymmetric microsphere resonant cavities (ARCs) allow for free-space coupling to high quality (Q) whispering gallery modes (WGMs) while exhibiting highly directional light emission, enabling WGM resonance measurements in the far-field. These remarkable characteristics make “stand-off” biodetection in which no coupling device is required in near-field contact with the resonator possible. Here we show asymmetric microsphere resonators fabricated from optical fibers which support dynamical tunneling to excite high-Q WGMs, and demonstrate free-space coupling to modes in an aqueous environment. We characterize the directional emission by fluorescence imaging, demonstrate coupled mode effects due to free space coupling by dynamical tunneling, and detect adsorption kinetics of a protein in aqueous solution. Based on our approach, new, more robust WGM biodetection schemes involving microfluidics and in-vivo measurements can be designed. |
| Databáze: | OpenAIRE |
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