Design of a Photonic Crystal Defect Waveguide Biosensor Operating in Aqueous Solutions at 1.34 µm

Markus Wellenzohn,Rainer Hainberger,Eva Melnik,Liam O’Faolain,Paul Muellner

doi:10.3390/proceedings2131026

Markus Wellenzohn, Rainer Hainberger + Show 3 more

Open Access

https://doi.org/10.3390/proceedings2131026

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Publication Date: Nov 14, 2018
Citations: 4	License type: CC BY 4.0

Affiliation: Austrian Institute of Technology, FH Campus Wien

Abstract

A two-dimensional photonic crystal defect waveguide sensor based on CMOS-compatible silicon-on-insulator technology was designed for operation in aqueous solutions at a wavelength of 1.34 µm, by the use of the 3D Plane Wave Expansion and the Finite Difference Time Domain simulation method. An operation under water in this wavelength regime allows for a significantly smaller propagation loss in contrast to the state-of-the-art operation wavelength of photonic crystals at 1.55 µm. The sensor working principle is label-free and based on evanescent wave sensing exploiting the local refractive index change induced by the specific binding of target molecules to a capture molecules immobilized on the surface of the phontonic crystal structure. We experimentally proved the theoretical predications of our simulations and demonstrated the sensing functionality of the photonic crystal defect waveguide using the biotin-straptavidin binding system.

Highlights

The label-free detection of biomolecules in liquid samples is a highly desirable feature in a wide range of applications such as medical and pharmaceutical research, molecular diagnostics, environment monitoring, as well as process and quality control in food industry
All these concepts exploit the effective refractive index change of the guided optical wave that is induced by the specific binding of target molecules to a thin biochemical functionalization layer on top of the waveguide surface
We report the design of a 2D silicon photonic crystal (PhC) defect waveguide operating at 1.34 μm and demonstrate its suitability for biosensing by observing the binding of single and multi-layer biotin-streptavidin biofilms

Summary

Introduction

The label-free detection of biomolecules in liquid samples is a highly desirable feature in a wide range of applications such as medical and pharmaceutical research, molecular diagnostics, environment monitoring, as well as process and quality control in food industry. During the last decades various integrated optical waveguide concepts have been intensively investigated as a promising means to realize sensitive label-free biomolecule detection [1]. All these concepts exploit the effective refractive index change of the guided optical wave that is induced by the specific binding of target molecules to a thin biochemical functionalization layer on top of the waveguide surface. With respect to the choice of operation wavelength, propagation loss represents a very important issue because it directly impacts the overall sensing performance.

Sensor Concept and Photonic Crystal Defect Waveguide Design

Measurements and Results

Conclusions