MOF-on-MOF thin film coated optical fiber sensor for rapid humidity sensing
Abstract
We present a multi-mode optical fiber sensor that integrates a thin MOF-on-MOF coating layer (Co-ZIF-90 on ZIF-8) for humidity sensing. To fabricate the sensor, we first etched the fiber etched using commercial buffered oxide etchant (BOE) containing 40% ammonium fluoride and 49% hydrofluoric acid (HF) in a 6:1 ratio. A thin ZIF-8 layer was then grown on the fiber as the seeding layer using a simple solution method. Afterwards, the Co-ZIF-90 layer was grown on top of the ZIF-8 layer by immersing it in a freshly prepared mixture of equal volumes of "Co"and "HImCA". This process yielded a Co-ZIF-90-on-ZIF-8 thin layer approximately 400 nm thick. The humidity sensing performance was characterized accordingly. Experimental results show that the developed optical fiber sensor exhibits high sensitivity to water vapor (79.2% transmission changes) with a rapid adsorption time of 1 second and desorption time of 2 seconds, respectively. The MOF-based fiber sensor's excellent reversibility in the adsorption and desorption of sensing target molecules was also demonstrated. This proof-of-concept study provides an alternative method for easy fabrication of MOF-based optical sensing devices and opens up new application potentials for combination of functional material and optics for selective chemical detection and sensing.
Details
- Organisation(s)
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PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
Hannover Centre for Optical Technologies (HOT)
Institute of Inorganic Chemistry
- Type
- Conference contribution
- Publication date
- 05.03.2026
- Publication status
- Published
- Peer reviewed
- Yes
- ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials, Instrumentation, Condensed Matter Physics, Computer Science Applications, Applied Mathematics, Electrical and Electronic Engineering
- Electronic version(s)
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https://doi.org/10.1117/12.3081216 (Access:
Closed
)
