In this paper we propose an optical biosensor based on two vertically stacked Silicon on Insulator (SOI) micro-ring resonators interacting with a microfluidic ring channel. This device behaves as a resonant optical coupler and it is very sensitive to the variation of the coupling coefficient between the two vertically stacked ring resonators. A ring microfluidic channel is proposed in the coupling region between the two vertically stacked ring resonators. The inner walls of the channel are funzionalized in order to the trap a specific biological species. Assuming a biotin-streptavidin system, the straptividin trapping gives rise to a change of the biological thickness of about 3 nm. This thickness increase of the deposited layer leads to a consequent change in the coupling strength between the two rings. These theoretical predictions have been validated by using both 3D Finite-Difference Time-Domain (FDTD) and 3D full-vectorial Finite Element Method (FEM) approaches. Moreover, by appropriately choosing the design parameters of the micro-resonant structure, we evaluate a sensitivity of the spectral response to the streptavidin adlayer variation of about 20% nm(-1) for TE polarization and 34% nm(-1) for TM polarization, which represents an important achievement to obtain selective SOI bio-sensors with ultra-high resolution.

A high efficiency label-free photonic biosensor based on vertically stacked ring resonators / Campanella, C. E.; Campanella, C. M.; DE LEONARDIS, Francesco; Passaro, Vittorio. - In: THE EUROPEAN PHYSICAL JOURNAL. SPECIAL TOPICS. - ISSN 1951-6355. - 223:10(2014), pp. 2009-2021. [10.1140/epjst/e2014-02244-5]

A high efficiency label-free photonic biosensor based on vertically stacked ring resonators

DE LEONARDIS, Francesco;PASSARO, Vittorio
2014-01-01

Abstract

In this paper we propose an optical biosensor based on two vertically stacked Silicon on Insulator (SOI) micro-ring resonators interacting with a microfluidic ring channel. This device behaves as a resonant optical coupler and it is very sensitive to the variation of the coupling coefficient between the two vertically stacked ring resonators. A ring microfluidic channel is proposed in the coupling region between the two vertically stacked ring resonators. The inner walls of the channel are funzionalized in order to the trap a specific biological species. Assuming a biotin-streptavidin system, the straptividin trapping gives rise to a change of the biological thickness of about 3 nm. This thickness increase of the deposited layer leads to a consequent change in the coupling strength between the two rings. These theoretical predictions have been validated by using both 3D Finite-Difference Time-Domain (FDTD) and 3D full-vectorial Finite Element Method (FEM) approaches. Moreover, by appropriately choosing the design parameters of the micro-resonant structure, we evaluate a sensitivity of the spectral response to the streptavidin adlayer variation of about 20% nm(-1) for TE polarization and 34% nm(-1) for TM polarization, which represents an important achievement to obtain selective SOI bio-sensors with ultra-high resolution.
2014
A high efficiency label-free photonic biosensor based on vertically stacked ring resonators / Campanella, C. E.; Campanella, C. M.; DE LEONARDIS, Francesco; Passaro, Vittorio. - In: THE EUROPEAN PHYSICAL JOURNAL. SPECIAL TOPICS. - ISSN 1951-6355. - 223:10(2014), pp. 2009-2021. [10.1140/epjst/e2014-02244-5]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11589/6951
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