Optical Sensors Based on Whispering Gallery Modes in Fluorescent Microbeads: Size Dependence and Influence of Substrate

doi:10.3390/s90906836

This article is

freely available
re-usable

Sensors 2009, 9(9), 6836-6852; doi:10.3390/s90906836

Article

Optical Sensors Based on Whispering Gallery Modes in Fluorescent Microbeads: Size Dependence and Influence of Substrate

Alexandre Francois ^1,2 and Michael Himmelhaus ¹^,*

¹ Fujirebio, Inc. / 51 Komiya-cho, Hachioji-shi 192-0031, Tokyo, Japan
² Present address: Centre of Expertise in Photonics / School of Chemistry and Physics, The University of Adelaide, 5005 Australia

^* Author to whom correspondence should be addressed.

Received: 7 August 2009; in revised form: 20 August 2009 / Accepted: 20 August 2009 / Published: 31 August 2009

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Japan)

Download PDF Full-Text [483 KB, uploaded 30 August 2009 16:30 CET]

Abstract: Whispering gallery modes in surface-fixated fluorescent polystyrene microbeads are studied in view of their capability of sensing changes in the refractive index of the beads’ environment by exposing them to water/glycerol mixtures of varying composition. The mode positions are analyzed by simultaneous fitting for mode number, bead radius, and environmental index. Down to a diameter of 8 μm, the sensor response follows the index of the bulk solution very well. For smaller bead sizes, some deviations occur, in particular for fluid indices not too different from that of water, which might be attributed to the presence of the substrate.

Keywords: whispering gallery modes; cavity modes; optical sensing; refractive index sensing; biosensing

Article Statistics

Click here to load and display the download statistics.

Cite This Article

MDPI and ACS Style

Francois, A.; Himmelhaus, M. Optical Sensors Based on Whispering Gallery Modes in Fluorescent Microbeads: Size Dependence and Influence of Substrate. Sensors 2009, 9, 6836-6852.

AMA Style

Francois A., Himmelhaus M. Optical Sensors Based on Whispering Gallery Modes in Fluorescent Microbeads: Size Dependence and Influence of Substrate. Sensors. 2009; 9(9):6836-6852.

Chicago/Turabian Style

Francois, Alexandre; Himmelhaus, Michael. 2009. "Optical Sensors Based on Whispering Gallery Modes in Fluorescent Microbeads: Size Dependence and Influence of Substrate." Sensors 9, no. 9: 6836-6852.

Sensors EISSN 1424-8220 Published by MDPI Publishing, Basel, Switzerland RSS E-Mail Table of Contents Alert