Tandem MOF-Based Photonic Crystals for Enhanced Analyte-Specific Optical Detection

Abstract

Owing to their structural variability, metal− organic frameworks (MOFs) lend themselves well as chemical sensing materials by providing both high sensitivity and selectivity. Here, we integrate different types of MOFs (ZIF-8, HKUST-1, CAU-1-NH 2 ) into photonic multilayers referred to as Bragg stacks (BSs), which report on adsorption events through changes in their effective refractive index (RI). The fabrication of photonic multilayers is accomplished by spincoating colloidal suspensions of MOF nanoparticles and/or the high RI-material TiO 2 . While their incorporation in BSs allows for the label-free readout of host−guest interactions, the choice of particular types of MOFs determines the sensing properties of the BS. Here, we present MOF-based BSs with enhanced specificity toward molecular analytes by combining two different MOFs in a single platform. The sensing performance of our BSs is demonstrated by a combined spectroscopic and principal component analysis of their vapor response. Time-dependent measurements reveal fast response times and good recoverability of the multilayers. Moreover, we demonstrate that combinatorial sensing is feasible by arranging different MOF BSs in a basic color pattern, which highlights the potential of MOF-based multilayers in arrayed sensor devices.

Tuning optical properties of MOF-based thin films by changing the ligands of MOFs

“…Consequently, some efforts [17][18][19][20][21][22][23][24][25] have been made to explore the application of MOFs in optical thin films. Férey and coworkers [17] first described a simple route for the preparation of flexible porous iron carboxylate MIL-89 optical thin films using the dip-coating method.…”

“…Lu et al [21] constructed ZIF-8-based Fabry-Pérot devices via a direct growth method that functions as selective sensors for chemical vapors and gases. Ranft et al [22] fabricated tandem MOF-based photonic crystals for enhanced analyte-specific optical detection by spin-coating. Our group [23,24] also fabricated flexible MOF-based photonic films for sensing.…”

Application of metal and metal oxide nanoparticles@MOFs

“…Nevertheless, the particle spin-coating method remains popular, mainly because of its simplicity and general applicability [154,155] and the deposition of HKUST-1 layers via the step-by-step protocol (Fig. 10e) [157].…”

SURMOFs: Liquid-Phase Epitaxy of Metal-Organic Frameworks on Surfaces

“…Such a device gives different optical responses depending on the molecules which are loaded in the MOFs. BSs have also been prepared with alternating bulk MOF-based layers (ZIF-8, HKUST-1, and CAU-1-NH 2 ) and TiO 2 layers by spin-coating substrates with the colloidal suspension of the corresponding MOF [69].…”