Metal-Organic Framework Thin Film Coated Optical Fiber Sensors: A Novel Waveguide-Based Chemical Sensing Platform.
Integration of optical fiber with sensitive thin films offers great potential for the realization of novel chemical sensing platforms. In this study, we present a simple design strategy and high performance of nanoporous metal-organic framework (MOF) based optical gas sensors, which enables detection of a wide range of concentrations of small molecules based upon extremely small differences in refractive indices as a function of analyte adsorption within the MOF framework. Thin and compact MOF films can be uniformly formed and tightly bound on the surface of etched optical fiber through a simple solution method which is critical for manufacturability of MOF-based sensor devices. The resulting sensors show high sensitivity/selectivity to CO2 gas relative to other small gases (H2, N2, O2, and CO) with rapid (<tens of seconds) response time and excellent reversibility, which can be well correlated to the physisorption of gases into a nanoporous MOF. We propose a refractive index based sensing mechanism for the MOF-integrated optical fiber platform which results in an amplification of inherent optical absorption present within the MOF-based sensing layer with increasing values of effective refractive index associated with adsorption of gases.
['Kim|Ki-Joong|KJ|0000-0001-9374-8103', 'Lu|Ping|P|', 'Culp|Jeffrey T|JT|', 'Ohodnicki|Paul R|PR|']
D002245:Carbon Dioxide D003035:Cobalt D004784:Environmental Monitoring D007093:Imidazoles D000073396:Metal-Organic Frameworks D055100:Optical Fibers D016062:Porosity D013499:Surface Properties D017641:Zeolites
optical fiber sensor carbon dioxide sensing chemical sensor metal−organic framework thin film small gases sensing