Ethanol Effect on Graphene Drop Casting for Acetone Vapor Sensors Operating at Room Temperature

Acetone vapor sensors find great use in many areas as they are being used for non-invasive diabetes detection and monitoring, fat burning rate monitoring, general industrial applications or even detection of explosive environments. Even though several sensors have been proposed, there is a continuous need for low power and low-cost ones, ideally implemented on flexible substrates. Thus, 2D nanomaterials such as graphene, due to their large specific surface area and exceptional electrical properties, have attracted broad attention for their gas sensing potential even at low temperature range of operation. As an example, recently, an acetone sensor was shown using graphene nanoplatelets combined with Zinc ferrite (ZnFe₂O₄) and achieved a sensitivity of 7% at 200 ppm acetone vapor while operating at 275°C. In this work, we compare various graphene-based gas sensors, capable of detecting acetone vapors, that are implemented on glass substrates and operate at room temperature. We demonstrate that such sensors exhibit good repeatability and sensitivity at 200 ppm of acetone vapor. All acetone sensing measurements were conducted by exposing the sensors in repeating cycles of several acetone concentrations diluted in nitrogen gas. To test the repeatability of the sensors, they were exposed to three cycles of 200 ppm acetone vapors followed by nitrogen gas during recovery. The sensors were tested in room temperature.

Michael Georgas, George Zardalidis, Filippos Farmakis