Optical sensor array of metal-organic-framework-based inverse opal films for the detection and identification of various alcohols

Reliable and inexpensive sensors for the detection and discrimination of various volatile organic compounds like different alcohols are required for many applications, for example to proof the alcohol quality and for avoiding methanol poising. Here, we develop a sensor array of films made of different types of surface-mounted metalorganic frameworks (SURMOFs) with a periodic three-dimensional structure of mesoscopic voids, referred to as inverse opal structure. The wavelength shift (or alternatively, the intensity change) of the photonic reflectance peak caused by the analyte vapor adsorption in the SURMOF was used as signal. The sensor array is applied for the detection of various pure low-carbon alcohols, which are methanol, ethanol, 1-propanol, and 1-butanol. The sensor array shows a low limit of detection (LOD) in the range of 10-60 ppm and is able to reliably discriminate the alcohols from each other. Furthermore, the sensor array is able to precisely discriminate their pure vapors and binary mixtures with methanol. We foresee such sensor array with SURMOF-based inverse opal films offer a great potential for the precise and cost-efficient detection of various analytes.