Application of metal organic framework crystals for sensing of volatile organic gases

In this work, metal organic frameworks are used for the first time to detect volatile organic compounds. A sensitive nanoporous metal organic framework layer was deposited using a custom electrospraying system onto the surface of quartz resonators to build a gravimetric sensor. The response of sensors made using the electrosprayed film is compared against those prepared with the more common technique of drop-casting. It is demonstrated that our electrospraying technique resulted in a significantly higher quality factor for the quartz resonators which leads to improved sensor resolution and stability. The experimental set-up is presented and the response of the system to various concentrations of the vapours of three ubiquitous solvents, i.e., acetone, tetrahydrofuran, and isopropyl alcohol, is investigated. The minimum detectable concentrations of these organic vapours are 50 ppm, 10 ppm, and 2 ppm, respectively.