QCM-based ammonia gas sensors with electrospun polymer-based nanofibers for liver and kidney disease detection: a mini-review

The advanced development of ammonia gas sensors using various sensing platforms has been widely researched, including quartz crystal microbalance (QCM)-based sensors. This review highlights recent research on ammonia gas sensors based on QCM with an electrospun polymer-based nanofiber active layer. The discussion starts with the principle of QCM as a base sensor, and then follows with the effect of electrospinning parameters on the fabricated nanofiber. Then, the discussion focuses on the potential of fabricated QCM-based sensors in directly detecting ammonia as a biomarker of liver and kidney diseases. The key performance parameters of QCM-based ammonia gas sensors, such as sensitivity, detection range, detection limit, and response/recovery time, are comprehensively discussed in this review. Finally, the potential, current challenges, and future perspectives on the application of QCM-based ammonia gas sensors for direct detection of liver and kidney diseases, such as improving selectivity, humidity resistance, and clinical translation, followed by the potential usage of QCM-based sensor arrays, are considered, offering insight into the future direction of QCM-based sensors in probing human diseases.