Universiti Teknologi Malaysia Institutional Repository

Planar silicon nitride waveguides for biosensing

V. Nabok, A. and Haron, S. and Ray, A. K. (2003) Planar silicon nitride waveguides for biosensing. In: IEE Proc.-Nanotechnol, 2003.

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Official URL: DOI:http://dx.doi.org/10.1049/ip-nbt:20030571

Abstract

The principles of attenuation of the light intensity due to multiple reflections are realised in a planar silicon oxide (SiO2)/silicon nitride (Si3N4) waveguiding structure for the purpose of developing optical biosensors with improved sensitivity. The analysis of the experimental data shows that the large difference in refractive indices of core and cladding layers gives rise to an increase in sensitivity by a factor of 3 over previously reported structures. Composite polyelectrolyte self-assembled thin films containing cyclo-tetra-chromotropylene as an indicator and enzymes glucose oxidase or urease were employed in the superstrate as a sensing membrane. Individual enzyme reactions as well as their inhibition by pesticides were studied by monitoring the intensity of light output from the planar waveguide. The results were compatible with those obtained by conventional ultraviolet-visible absorption spectroscopy. The instrument detection limit for Imidacloprid pesticide was found to be as low as 10 ppb in concentration.

Item Type:Conference or Workshop Item (Paper)
Uncontrolled Keywords:planar silicon nitride, biosensing
Subjects:Unspecified
Divisions:Others
ID Code:22089
Deposited By: Liza Porijo
Deposited On:02 Sep 2014 07:23
Last Modified:02 Sep 2014 07:23

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