| Title: | VOC Mixture Sensing with a MOF Film Sensor Array: Detection and Discrimination of Xylene Isomers and Their Ternary Blends |
| Author(s): | Qin P; Day BA; Okur S; Li C; Chandresh A; Wilmer CE; Heinke L; |
| Address: | "Karlsruhe Institute of Technology (KIT), Institute of Functional Interfaces (IFG), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, Unites States. Department of Electrical & Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, Unites States" |
| DOI: | 10.1021/acssensors.2c00301 |
| ISSN/ISBN: | 2379-3694 (Electronic) 2379-3694 (Linking) |
| Abstract: | "Detection and recognition of volatile organic compounds (VOCs) are crucial in many applications. While pure VOCs can be detected by various sensors, the discrimination of VOCs in mixtures, especially of similar molecules, is hindered by cross-sensitivities. Isomer identification in mixtures is even harder. Metal-organic frameworks (MOFs) with their well-defined, nanoporous, and versatile structures have the potential to improve the VOC sensing performance by tailoring the adsorption affinities. Here, we detect and identify ternary xylene isomer mixtures by using an array of six gravimetric, quartz crystal microbalance (QCM)-based sensors coated with selected MOF films with different isomer affinities. We use classical molecular simulations to provide insights into the sensing mechanism. In addition to the attractive interaction between the analytes and the MOF film, the isomer discrimination is caused by the rigid crystalline framework sterically controlling the access of the isomers to different adsorption sites in the MOFs. The sensor array has a very low limit of detection of 1 ppm for each pure isomer and allows the isomer discrimination in mixtures. At 100 ppm, 16 different ternary o-p-m-xylene mixtures were identified with high classification accuracy (96.5%). This work shows the unprecedented performance of MOF-sensor arrays, also referred to as MOF-electronic nose (MOF-e-nose), for sensing VOC mixtures. Based on the study, guidelines for detecting and discriminating complex mixtures of volatile molecules are also provided" |
| Keywords: | Electronic Nose *Metal-Organic Frameworks/chemistry Quartz Crystal Microbalance Techniques *Volatile Organic Compounds/chemistry Xylenes metal-organic frameworks sensors ternary mixtures xylene; |
| Notes: | "MedlineQin, Peng Day, Brian A Okur, Salih Li, Chun Chandresh, Abhinav Wilmer, Christopher E Heinke, Lars eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2022/06/09 ACS Sens. 2022 Jun 24; 7(6):1666-1675. doi: 10.1021/acssensors.2c00301. Epub 2022 Jun 8" |
