Sensitive Detection of Alcohol Isomers by Ionically Conductive Metal-Organic Frameworks

Alcohols are an important class of organic compounds with many isomers, which play a crucial role in different applications. It is meaningful to develop a convenient method to identify the specific alcohol. However, compact sensors capable of distinguishing different alcohols are still challenging. In this work, utilizing metal ions as charge carriers, capacitive alcohol sensors on the basis of Co-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin ionically conductive metal-organic frameworks (IC-MOFs) are applied to sense various alcohols and obtain diverse responses for the first time, which can distinguish methanol, ethanol, propanol, and butanol. Besides, the devices show fast sensing speed with a t(90) response time around 3 s. After 60 days of storage test under ambient atmosphere, the devices exhibit remarkable stability with negligible change in the sensing response. Furthermore, the sensors show interesting potential through a demonstration, in which the devices can detect 1% methanol doped in vodka. The results provide a new approach to detect different alcohols and corresponding isomers quickly and make IC-MOF sensors competitive candidates in chemical sensing.