Improving ammonia sensing performance of quartz crystal microbalance (QCM) coated with nanofibers and polyaniline (PANi) overlay

• Published in: Biosensors and bioelectronics. X Vol. 13; p. 100300
• Main Authors: Aflaha, Rizky, Afiyanti, Henny, Azizah, Zhafirah Nur, Khoirudin, Hanif, Rianjanu, Aditya, Kusumaatmaja, Ahmad, Roto, Roto, Triyana, Kuwat
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2023; Elsevier
• Subjects: Ammonia; Nanofiber; Polyaniline; Polyvinyl acetate; Quartz crystal microbalance; Ammonia; Nanofiber; Quartz crystal microbalance; Polyaniline; Polyvinyl acetate
• ISSN: 2590-1370; 2590-1370
• DOI: 10.1016/j.biosx.2022.100300

Ammonia gas sensors with high sensitivity, good selectivity, and superior stability continue to be developed to monitor ammonia levels in the air. In this study, we developed a sensor based on a quartz crystal microbalance coated with polyvinyl acetate (PVAc) nanofiber overlaid with a polyaniline (PANi) nanocomposite to increase the sensitivity and selectivity of the sensor. The morphology and chemical composition of the fabricated nanofibers were examined by scanning electron microscopy and Fourier transform infrared spectroscopy. PANi nanocomposites were shown to stick to nanofiber, and nanofiber became many active groups after PANi overlay. The QCM sensor coated with the PVAc nanofiber overlaid with 0.05% PANi (PVAc/PANi5) exhibited the highest sensitivity of 0.297 Hz/ppm. This value was increased 5.2 times compared to the sensor without the PANi overlay (0.055 Hz/ppm). The PVAc/PANi5 sensor exhibited good reproducibility, repeatability, and reversibility. Moreover, a rapid response (36 s) and recovery (26 s) time were observed. The sensor also showed good selectivity towards other analytes and was proven to have good long-term stability during two months of testing. This finding may potentially be an alternative method for increasing the ammonia-sensing performance of a sensor through overlaying.
•Modified quartz crystal microbalance surface with nanofibers and polyaniline overlay has been tested for ammonia detection.•PANi overlay to nanofiber can improve the sensitivity and selectivity of ammonia gas sensing.•The sensor reported good characteristics, such as reproducibility, reversibility, repeatability, and long-term stability.•Improvement in sensor performances is believed to be due to hydrogen bonds between the PANi and ammonia gas molecules.
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