Graphite-based multi-analyte VOC gas detection on multichannel PCB IDE sensor

In this article, we present the development of a volatile organic compound (VOC) gas sensor based on graphite on a printed circuit board (PCB) multiplexed interdigitated electrode (IDE) sensor. We report the effects of graphite as a sensing material deposited by the spray method and its interaction response to specific gases. In addition, we demonstrate how we designed and manufactured IDE sensors with an integrated heating circuit and thermistor element, as well as the 55- $\mu \text{L}$ microchamber, which contributed to the fast detection of gases. All experiments were performed with four IDE sensors to verify the reproducibility and sensitivity of the proposed methodology. Our results highlight that acetone presented the highest detection sensitivity, with an electric current increase of ± $100~\mu \text{A}$ at a 200-ppm cycle with a response of 0.92 s and full recovery at 2.62 s. Furthermore, the developed sensors were able to detect and distinguish between acetone, methanol, isopropanol, ethanol, and chloroform gases. The sensors exhibited outstanding stability and repeatability when evaluated after six months. The sensors’ operation at 2 V makes it suitable for low-power devices with a high potential to be applied in future commercial room-temperature VOC gas sensor devices.