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Optical sensing of biomolecules using microring resonators

2006; IEEE Photonics Society; Volume: 12; Issue: 1 Linguagem: Inglês

10.1109/jstqe.2005.863003

1558-4542

Ayça Yalcın, Ketul C. Popat, J. Aldridge, Tejal A. Desai, J.V. Hryniewicz, Nabil Chbouki, Brent E. Little, O. King, Vien Van, Sai T. Chu, D. Gill, M. Anthes-Washburn, M. Selim Ünlü, Bennett B. Goldberg,

Photonic Crystals and Applications

A biosensor application of vertically coupled glass microring resonators with Q/spl sim/12 000 is introduced. Using balanced photodetection, very high signal to noise ratios, and thus high sensitivity to refractive index changes (limit of detection of 1.8/spl times/10/sup -5/ refractive index units), are achieved. Ellipsometry and X-ray photoelectron spectroscopy results indicate successful modification of biosensor surfaces. Experimental data obtained separately for a bulk change of refractive index of the medium and for avidin-biotin binding on the ring surface are reported. Excellent repeatability and close-to-complete surface regeneration after binding are experimentally demonstrated.