Two-dimensional thin and porous membranes for gas molecules sensing

Two-dimensional metal-organic frameworks (MOFs) demonstrate the advantages of organo-inorganic nature such as operation efficiency, and stability for optical sensing. For achieving high selectivity and operational performance optical properties of MOFs nanosheets can be varied by choosing the metal centers and the linking ligands. According to 2D nature, the material could be exfoliated up to monolayer height, which drastically increases the effective surface area of the sensor. The existing challenge is to preserve the lateral size of the membrane while reducing the height of the material. In this work, we have overcome the described challenge and obtained high-quality 2D MOF layers with a record for MOF aspect ratio (21300:1) and demonstrated unique optical sensitivity to solvents of varied polarity. Developed method of membrane fabrication opens the way to produce scalable and freestanding 2D MOF-based atomically thin chemo-optical sensors by an industry-oriented approach.