Strain-Based Chemical Sensing Using Metal-Organic Framework Nanoparticles
Metal-organic frameworks (MOFs) have received much attention for their potential as chemical sensors, owing to unparalleled tunability of their host-guest response. However, because of the limited compatibility between MOF properties and sensor transduction mechanisms, very few MOFs have successfully been integrated into practical devices. We report the fabrication of a strain-based sensor constructed from MOF nanoparticles deposited directly onto a membrane-type surface stress sensing architecture, which exhibits response times on the order of seconds and ppm-level sensitivity towards volatile organic compounds (VOCs). We show that an array of four types of MOF nanoparticles allows for clear discrimination between VOCs, using principal component analysis of their response profiles. This work opens up the possibility of VOC sensing using a wide range of MOFs, beyond those that are electrically conducting or those that form oriented thin films, with the added advantages of high sensitivity and rapid response.