Optical Biosensor Using an Exposed Core Microstructured Optical Fiber

Abstract

In this work a label-free optical biosensor based on an exposed core microstructured optical fiber (ECF) is presented. Thanks to the exposed core of the ECF, light propagating in the fiber core can have direct access to the analytes in the sensing liquid, while maintaining the mechanical strength of the fiber. The multimode interference effect within ECF, created due to the phase delay between guided modes in the core, was used as the transduction mechanism. Biotin-streptavidin as well as a his-tag capture probe and His-tagged protein were used to demonstrate biosensing capabilities of the proposed platform. Preliminarily results on using the ECF within a laser cavity to improve the sensor resolution are also discussed. Our proposed optical biosensors is an plug-and-play configuration without bulk optic components and thus has potential for use as portable devices for in-field surveillance of pathogens.