Improved Cyclohexanone Vapor Detection via Gravimetric Sensing

Functionalized gravimetric sensors are a promising path to small, versatile, real-time vapor sensors for volatile organic compounds. Many of these compounds can be dangerous to human health, but their nonreactive nature makes them notoriously difficult to sense. Unlike bulk acoustic resonators, chemiresistive devices have been investigated extensively and many researchers have used innovative synthesis strategies to functionalize these devices. In this work, we demonstrate how modifying a particular sensitizer for use with a bulk acoustic resonator significantly improves the sensitivity of the device (5 ppm vs. 1.11 ppm). Additionally, readout circuitry is described to avoid some problems that typically plague gravimetric sensors while simplifying the overall system. These strategies create a playbook for simple, fast, and sensitive systems for sensing volatile organic compounds, while also demonstrating the lowest limit of detection for cyclohexanone outside of gas chromatography/mass spectrometery in the literature. [2020-0053]