Share Email Print

Proceedings Paper

Application of ring down measurement approach to micro-cavities for bio-sensing applications
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Optical biosensors can detect biomarkers in the blood serum caused by either infections or exposure to toxins. Until now, most work on the micro-cavity biosensors has been based on measurement of the resonant frequency shift induced by binding of biomarkers to a cavity. However, frequency domain measurements are not precise for such high Q micro-cavities. We hypothesize that more accurate measurements and better noise tolerance can be achieved by the application of the ring down measurement approach to the micro-cavity in a biosensor. To test our hypothesis, we have developed a full vectorial finite element model of a silica toroidal micro-cavity immersed in water. Our modeling results show that a toroidal cavity with a major diameter of 70μm and a minor diameter of 6μm can achieve a sensitivity of 28.6μs/RIU refractive index units (RIU) at 580nm. Therefore, our sensor would achieve the resolution of 5 x 10-8 RIU by employing a detector with picosecond resolution. Hence we propose a micro-cavity ring down biosensor with high sensitivity which will find wide applications in real time and label free bio-sensing.

Paper Details

Date Published: 8 February 2011
PDF: 8 pages
Proc. SPIE 7888, Frontiers in Biological Detection: From Nanosensors to Systems III, 788808 (8 February 2011); doi: 10.1117/12.874890
Show Author Affiliations
M. Imran Cheema, McGill Univ. (Canada)
Andrew G. Kirk, McGill Univ. (Canada)

Published in SPIE Proceedings Vol. 7888:
Frontiers in Biological Detection: From Nanosensors to Systems III
Benjamin L. Miller; Philippe M. Fauchet, Editor(s)

© SPIE. Terms of Use
Back to Top