Next Article in Journal
Determination of Zinc, Cadmium and Lead Bioavailability in Contaminated Soils at the Single-Cell Level by a Combination of Whole-Cell Biosensors and Flow Cytometry
Next Article in Special Issue
An Optical Biosensor from Green Fluorescent Escherichia coli for the Evaluation of Single and Combined Heavy Metal Toxicities
Previous Article in Journal
Optimization of Capacitive Acoustic Resonant Sensor Using Numerical Simulation and Design of Experiment
Previous Article in Special Issue
Optical Nano Antennas: State of the Art, Scope and Challenges as a Biosensor Along with Human Exposure to Nano-Toxicology
Article Menu

Export Article

Open AccessArticle
Sensors 2015, 15(4), 8968-8980; doi:10.3390/s150408968

Stand-Off Biodetection with Free-Space Coupled Asymmetric Microsphere Cavities

Max Planck Institute for the Science of Light, Laboratory of Nanophotonics & Biosensing, Guenther-Scharowsky-Str. 1/Bldg. 24, Erlangen D-91058, Germany
*
Authors to whom correspondence should be addressed.
Academic Editor: Frances Ligler
Received: 21 November 2014 / Revised: 9 April 2015 / Accepted: 10 April 2015 / Published: 16 April 2015
(This article belongs to the Special Issue Advances in Optical Biosensors)
View Full-Text   |   Download PDF [2063 KB, uploaded 17 April 2015]   |  

Abstract

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. View Full-Text
Keywords: Whispering Gallery Mode (WGM) biosensors; free-space coupling; asymmetric resonant cavities; biosensing; label-free detection; protein adsorption Whispering Gallery Mode (WGM) biosensors; free-space coupling; asymmetric resonant cavities; biosensing; label-free detection; protein adsorption
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Ballard, Z.; Baaske, M.D.; Vollmer, F. Stand-Off Biodetection with Free-Space Coupled Asymmetric Microsphere Cavities. Sensors 2015, 15, 8968-8980.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top