Metal–organic framework-based photonic crystal platforms for gas sensing: a review

Abstract

Based on the low cost, high sensitivity and high reliability of photonic crystal (PC) platforms, they stand out in the family of gas sensors for label-free gas detection. Numerous breakthroughs have been achieved in terms of response speed, selectivity and specificity by integrating MOFs in PC sensors as functional materials, resulting in the formation of metal-organic framework (MOF)-based PC gas sensors. Due to the combination of the photonic band gap (PBG) of PCs with the specific properties of MOFs, such as tunable structure, diversity, large porosity and high specific surface area, tremendous progress has been made in the past decade on MOF-based PC gas sensors with high sensitivity and selectivity. However, although there are several reviews in the literature summarizing the use of MOFs as gas sensors, a comprehensive review focusing on MOF-based PC gas sensors from 1-dimensional (1-D) to 3-D PCs is lacking. In this review, the research progress on MOF-based PC gas sensors from 1-D to 3-D PCs, which mainly include four aspects of sensing mechanism, material selection, structural optimization and sensing performances, is comprehensively summarized. Firstly, an overview of the corresponding sensing principle for PC sensors is presented. Further, the sensing properties such as sensitivity, response and recovery time, limit of detection (LOD), selectivity, and repeatability of various MOF-based PC sensing systems are illustrated and discussed. Finally, a summary and outlook of MOF-based PC gas sensors are presented to pave the way for their practical applications.