Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/82022
Title: Highly sensitive Mach–Zehnder interferometer biosensor based on silicon nitride slot waveguide
Authors: Liu, Qing
Tu, Xiaoguang
Kim, Kyung Woo
Kee, Jack Sheng
Shin, Yong
Han, Kyungsup
Yoon, Yong-Jin
Lo, Guo-Qiang
Park, Mi Kyoung
Keywords: Mach–Zehnder interferometer
Silicon nitride waveguide
Issue Date: 2013
Source: Liu, Q., Tu, X., Kim, K. W., Kee, J. S., Shin, Y., Han, K., et al. (2013). Highly sensitive Mach–Zehnder interferometer biosensor based on silicon nitride slot waveguide. Sensors and Actuators B: Chemical, 188, 681-688.
Series/Report no.: Sensors and Actuators B: Chemical
Abstract: We demonstrate a highly sensitive label-free Mach–Zehnder interferometer (MZI) biosensor based on silicon nitride slot waveguide. Unlike the conventional MZI sensors, the sensing arm of the sensor consists of a slot waveguide while the reference arm consists of a strip waveguide. Thanks to the slot waveguide's property to provide high optical intensity in a subwavelength-size low refractive index region (slot region), which allows high light–analyte interaction, higher sensitivity can be obtained as compared to conventional waveguides using the slot waveguide as sensing region. The bulk refractive index sensitivity of the slot waveguide MZI sensor was found to be 1864π/RIU (refractive index unit) with 7 mm long slot waveguide sensing arm, which shows higher sensitivity compared to the conventional MZI device based on silicon nitride. The biosensing capability of the developed slot waveguide MZI was investigated using biotin–streptavidin binding as a model system. The sensitivity of the system was demonstrated down to 18.9 fM or 1 pg/ml of streptavidin solution and to the best of our knowledge, it is the best reported experimental value for the limit of detection of a MZI sensor. Furthermore, we investigated the specific detection and quantification of the methylation of DAPK (Death-associated protein kinase) gene, which is a widely used biomarker for human cancers. We have shown that methylation sequences of DAPK gene of various methylation densities (100%, 50%, and 0% of methylation sites) can be quantified and discriminated even at a concentration as low as 1 fmol/μl or 1 nM.
URI: https://hdl.handle.net/10356/82022
http://hdl.handle.net/10220/41102
ISSN: 0925-4005
DOI: 10.1016/j.snb.2013.07.053
Rights: © 2013 Elsevier B.V.
Fulltext Permission: none
Fulltext Availability: No Fulltext
Appears in Collections:MAE Journal Articles

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