摘要 : Metal-organic frameworks (MOFs), also known as porous coordination polymers (PCPs), which are built through the coordination between metal ions/clusters and organic ligands, afford rigid structures, permanent high porosity and gre... 展开 Metal-organic frameworks (MOFs), also known as porous coordination polymers (PCPs), which are built through the coordination between metal ions/clusters and organic ligands, afford rigid structures, permanent high porosity and great chemical tunabilities. Endowed with numerous superior characteristics, MOFs have been garnering considerable attentions in the field of gas storage/separation, catalysis, biomedicine, sensing, etc. However, the study of MOFs as sensors is still in its infancy, in spite of their distinguished properties that render them promising candidates for sensing applications. As a result, research on MOFs as potential sensing materials can be of great importance and necessity. Thus far, a handful of MOF-based sensors have been constructed either by employing luminescent framework or by taking the advantage of photonic MOFs structures. Compared to luminescent MOFs, which rely on luminescent quenching for signal transduction, photonic MOFs structures require neither molecular level functionalization nor complicated signal detection, and thus representing a more attractive alternative in the field of sensing. Nevertheless, existing reports on photonic structures based sensors focused mainly on thin films, hybrid and template structures, which limits their generalization to MOFs-based sensors. On one hand, since the report of ZIF-8 thin film that works as a photonic sensor from Hupp's group, the studies in MOFs thin films have been rapidly developed. However, most of the films in literature were prepared based on methods highly related to their own properties. Thus, general strategies towards MOFs thin film preparation are still immature. On the other hand, the efficiency of fabricating template structures is not high due to the necessity of template fabrication and removal. Moreover, in order to improve the detection performance, other materials are usually incorporated into the system, which brings complexity into fabrication. From what introduced above, apparently a simple and general route towards fabricating MOFs sensors is still in great demand. Herein, we present the fabrication of a photonic sensor obtained through the self-assembly of MOFs crystals via Langmuir-Blodgett (LB) technique (Scheme 1). The self-assembly of nanoparticles of various sizes and shapes, including that of semiconductor nanoparticles (NPs), organic microspheres, metal NPs and metal oxide NPs has been thoroughly investigated in recent years. The studies on the applications of self-assembled structures, such as biosensor, catalysis and data storage, are getting more and more attractive. MOFs crystals are good candidates for the self-assembled structures. However, to the best of our knowledge, only a few studies have been carried on the self-assembly of MOFs crystals and none of them had investigated the applications of self-assembled MOFs structures. It is worthwhile noting that compared to other bottom-up strategies available, LB technique, which has always been playing a crucial role in directing the self-assembly of nanoparticles at air-liquid interface, is a fast and facile way to achieve the self-assembled MOFs structures. LB technique makes it possible to get assembled films consisting of MOFs crystals that cannot be directly prepared as thin films. Hence, LB technique was chosen for demonstrating the strategy of fabricating MOFs particle based photonic sensors. 收起