Volume 10 Issue 1 ( March 2023 )

Bioparticle concentration can be measured using many techniques, such as mass spectroscopy, light scattering, and fluorescent tracking. Due to some instrument limitations, high cost, low sensitivity-selectivity level, and performance development needs, there is a need to develop a new sensing technique with higher performance. This study used quartz crystal microbalance (QCM) and graphene oxide (GO) as the selective coating materials. For this purpose, two different sensors were tested: uncoated QCM and GO-coated QCM. The sensor performances were tested inside an exposure chamber by exposing the sensors to different bacteria samples: B. pasteurii, B. sphaericus, and B. cereus. The sensor’s frequency shift was counted using a frequency counter, while the sample concentration was measured using a Digital Dust Monitor. The results show that the sensors work well in detecting Bacillus sp. samples with sensitivities of 0.24 to 0.35 Hz.µg^-1 . The developed sensors have a response time of <96 s, with a linearity of 95%. The best response is obtained from the coated QCM using B. pasteurii. The coated QCM performs better than the uncoated QCM, indicated by better linearity, response time, and sensitivity.

Keywords: bacteria; bioparticle; fine particle; graphene oxide; quartz crystal microbalance