545c Zeolite Thin Film-Based Fiber Intrinsic Fabry-Perot Interferometric Sensor for Detection of Dissolved Organics and Ions in Water

Jian Zhang1, Ning Liu2, Juan Hui2, Hai Xiao2, and Junhang Dong1. (1) Chemical Engineering, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801, (2) Electrical Engineering, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801

A fiber optic intrinsic Fabry-Perot interferometric (IFPI) chemical sensor was developed by fine-polishing a thin layer of polycrystalline nanoporous MFI zeolite synthesized on the cleaved endface of a single mode fiber. The sensor operated by monitoring the optical thickness changes of the zeolite thin film caused by the adsorption of organic molecules into the zeolite channels or ion exchange. The optical thickness of the zeolite thin film was measured by whitelight interferometry. Using methanol, 2-propanol, and toluene as the model chemicals, it was demonstrated that the zeolite IPFI sensor could detect dissolved organics in water with high sensitivity. The sensor also showed good potential for detection of cations in aqueous solutions.