Engineering of metal-organic framework nanomaterials on long-period fiber grating for acetone vapor sensing

Haishi Wang; Guowei Deng; Lianghai Dong; Ke Zhao; Kaixin Chen; Kin Seng Chiang; Jieyun Wu

doi:10.1039/d2ra06038h

Engineering of metal-organic framework nanomaterials on long-period fiber grating for acetone vapor sensing

RSC Adv. 2022 Nov 25;12(52):33852-33858. doi: 10.1039/d2ra06038h. eCollection 2022 Nov 22.

Authors

Haishi Wang^{1

2}, Guowei Deng^{3

2}, Lianghai Dong², Ke Zhao², Kaixin Chen², Kin Seng Chiang⁴, Jieyun Wu²

Affiliations

¹ Collaborative Innovation Center of Integrated Computation and Chip Security, Chengdu University of Information Technology Chengdu China whs@cuit.edu.cn.
² School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China Chengdu China jieyunwu@uestc.edu.cn.
³ College of Chemistry and Life Science, Sichuan Provincial Key Laboratory for Structural Optimization and Application of Functional Molecules, Chengdu Normal University Chengdu China guoweideng86@163.com.
⁴ Department of Electrical Engineering, City University of Hong Kong Hong Kong China eeksc@cityu.edu.hk.

Abstract

Metal-organic framework (MOF) material is one of the most promising porous nanomaterials for volatile organic compound (VOC) adsorption and sensing. The large surface area and the high porosity of MOF contribute to the high sensitivity of MOF-based VOC sensors. In this study, we engineer the coating of the zeolitic imidazolate framework material ZIF-8 grown on the surface of a long-period fiber grating (LPFG) for acetone vapor sensing. Being a periodic structure formed in a single-mode optical fiber, an LPFG is designed to couple light from the core to the cladding of the fiber at a specific resonance wavelength. Adsorption of acetone vapor molecules in the framework of the ZIF-8 coating can change the refractive index of the coating and cause a shift in the resonance wavelength of the LPFG. The sensitivity of the resonance shift of the LPFG to the acetone vapor concentration depends strongly on the thickness of the ZIF-8 coating. To create a dense ZIF-8 coating, at least five growth cycles of ZIF-8 (30 min growth for one cycle) are required, and nine growth cycles can create a 500 nm thick coating. The LPFG coated with nine growth cycles of ZIF-8 provides a high sensitivity of 21.9 nm ppm^-1, a low detection limit of 1.4 ppm, and a wide detection range of about 1500 ppm. Our results can facilitate the development of high-performance optical fiber sensors based on MOF for VOC detection.