Quartz Crystal Microbalance Coated with a Polyvinylpyrrolidone Microfiber Active Layer as a High-Performance Acetic Acid Gas Sensor

Acetic acid is among the most common and damaging airborne contaminants. Exposure to acetic acid gas can irritate the nose and throat, which may harm human health. In light of the increasing use of acetic acid in industry, there is a critical need for an acetic acid detection device that can operate in real time with excellent performance. This study developed an acetic acid gas sensor using a quartz crystal microbalance (QCM) deposited with polyvinylpyrrolidone (PVP) microfiber by a well-recognized electrospinning method. Scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy were employed to observe the morphology and chemical composition of the fabricated microfibers. The obtained sensor has a high sensitivity of (4.144 ± 0.039) Hz·ppm^–1 with a low detection limit and rapid response and recovery times of 75 and 66 s, respectively. In addition, the fabricated sensor also exhibits good performance as well as repeatability and long-term stability. Selectivity tests were also conducted for various analytes and exhibited excellent selectivity toward acetic acid. These advancements demonstrate that the PVP microfiber active layers not only address the challenges of detection by enhancing sensitivity but also provide unique mechanism selectivity for acetic acid molecules. However, advanced future research must still be conducted to improve the sensor reversibility, making the sensor more suitable for applications in a real environment.