Electrospun Nanofibers for Quartz Crystal Microbalance Gas Sensors: A Review

In recent years, electrospun nanofibers made of various materials (e.g., polymers, composites, and semiconductors) have been extensively studied for the development of highly sensitive and selective gas sensors. These nanofibers possess unique three-dimensional (3D) interconnected porous structures that result in a large surface-area-to-volume ratio and high porosity. These properties have led to the widespread use of nanofibrous mats as active materials for mass-sensitive sensors, which use the gravimetric effect to measure the mass concentration of the adsorbed gases on their active surfaces. For this purpose, quartz crystal microbalance (QCM) has been considered as one of the most favorable mass-sensitive platforms because of its mature technology, low-cost production, fast sensing response, and highly flexible sensing area modification. This paper provides an overview of state-of-the-art QCM-based gas sensors that integrate electrospun nanofibers as their active materials. Several key parameters determining the sensor performance (e.g., sensitivity and limit of detection (LOD)) are summarized and discussed in relation to the current challenges. Finally, the outlook for future technological development is also provided.