Targeted high-resolution sensing of volatile organic compounds by covalent nanopore detection

Volatile organic compounds are choice analytes in a variety of contexts. For example, humans release over 4000 volatile organic compounds, many of which are diagnostic of life-threatening medical conditions. The analysis of combinations of a large number of potential analytes requires the application of costly, cumbersome technology. In this work, we show that covalent nanopore sensing can be used for the targeted detection of a reduced set of analytes in a mixture. In this case aldehydes, which constitute ~5% of human volatiles, can be selectively detected by using reversible thiol-aldehyde chemistry. Further, nanopore engineering permits high-resolution detection, which allows closely related aldehydes, including isomers, to be distinguished. Differential sensing of members of other chemical classes, such as mono alcohols, is also demonstrated by leveraging their enzymatic conversion into aldehydes. Our approach is compatible with the use of low-cost, portable, user-friendly diagnostic devices applicable to a wide variety of objectives, including pollutant monitoring, food and beverage testing and the quality control of pharmaceuticals, as well as disease diagnostics.