Microporous Triptycene‐Based Affinity Materials on Quartz Crystal Microbalances for Tracing of Illicit Compounds

• Published in: ChemPlusChem (Weinheim, Germany) Germany), 2019-09, Vol.84 (9), p.1239-1244
• Main Authors: Prantl, Ephraim, Kohl, Bernd, Ryvlin, Dimitrij, Biegger, Philipp, Wadepohl, Hubert, Rominger, Frank, Bunz, Uwe H. F., Mastalerz, Michael, Waldvogel, Siegfried R.
• Format: Article
• Language: English
• Subjects: affinity materials; quartz crystal microbalances; sensors; supramolecular chemistry; trace analysis
• ISSN: 2192-6506; 2192-6506
• DOI: 10.1002/cplu.201900189

Triptycene‐based organic molecules of intrinsic microporosity (OMIMs) with extended functionalized π‐surfaces are excellent materials for gas sorption and separation. In this study, the affinities of triptycene‐based OMIM affinity materials on 195 MHz high‐fundamental‐frequency quartz crystal microbalances (HFF‐QCMs) for hazardous and illicit compounds such as piperonal and (–)‐norephedrine were determined. Both new and existing porous triptycene‐based affinity materials were investigated, resulting in very high sensitivities and selectivities that could be applied for sensing purposes. Remarkable results were found for safrole – a starting material for illicit compounds such as ecstasy. A systematic approach highlights the effects of different size of π‐surfaces of these affinity materials, allowing a classification of the properties that might be optimal for the design of future OMIM‐based affinity materials. Lifted selectivity: Aided by their intrinsic mircoporosity, triptycene‐based affinity materials have ideal properties for quartz crystal microbalance sensing. The combination of these powerful affinity materials with high‐fundamental‐frequency quartz crystal microbalances (HFF‐QCMs) resulted in remarkable sensitivities and selectivities. In particular, a material with an exceptional affinity for safrole was found.