@article{AFLAHA2026108729,

title = {Performance evaluation and DFT study of a room temperature methylamine gas sensor based on QCM with Fe3O4-PVAc nanofiber active layer},

author = {Rizky Aflaha and Arif Lukmantoro and Selly Andaresta and Ghissani Mulan and Chlara Naren Maharani and Finantius Enrico M. Rahangiar and Yuliyan Dwi Prabowo and Aditya Rianjanu and Moh. Adhib Ulil Absor and Kuwat Triyana and Roto Roto and Witha Berlian Kesuma Putri},

url = {https://www.sciencedirect.com/science/article/pii/S2468023026003184},

doi = {https://doi.org/10.1016/j.surfin.2026.108729},

issn = {2468-0230},

year  = {2026},

date = {2026-04-01},

urldate = {2026-01-01},

journal = {Surfaces and Interfaces},

volume = {86},

pages = {108729},

abstract = {The negative impact of methylamine gas, which has the potential to harm the environment and human health, necessitates reliable sensors capable of detecting it at room temperature. The research developed a methylamine gas sensor based on a quartz crystal microbalance (QCM) with an active layer of polyvinyl acetate (PVAc) nanofibers and surface-modified with Fe3O4. PVAc nanofiber was fabricated using the electrospinning method, and then deposited with Fe₃O₄ using the dropcasting method. The PVAc nanofibers exhibited a smooth and continuous morphology and did not undergo damage after Fe₃O₄ deposition. The detection of Fe mass in the deposited nanofiber also confirmed the success of Fe₃O₄ addition. The sensor with Fe₃O₄ showed a significantly higher response to methylamine (51.5 Hz at 120 ppm) compared to the PVAc sensor (29.5 Hz at 120 ppm). The sensor also exhibits a high sensitivity of 0.442 Hz·ppm⁻¹ with a limit of detection of 9.2 ppm. In addition, Fe₃O₄ also accelerates the response and recovery times, while maintaining good selectivity and long-term stability. Furthermore, the density functional theory (DFT) calculations reveal stable adsorption energy, notable charge transfer, and short adsorption distances between methylamine and the Fe₃O₄ surface through Fe–N bonds. These findings indicate the strong gas-surface interaction, which is well-aligned with experimental results. This study demonstrates that the fabricated sensor exhibits reliable performance and has great potential as a room temperature methylamine gas sensor with high sensitivity and selectivity.},

keywords = {Density functional theory, FeO, Methylamine, Nanofiber, openQCM, Polyvinyl acetate, Quartz Crystal Microbalance},

pubstate = {published},

tppubtype = {article}

}

@article{aflaha2023maltodextrin,

title = {Maltodextrin-overlaid polyvinyl acetate nanofibers for highly sensitive and selective room-temperature ammonia sensors},

author = {Rizky Aflaha and Nur Laili Indah Sari and Laila Katriani and Ahmad Hasan As' ari and Ahmad Kusumaatmaja and Aditya Rianjanu and Roto Roto and Hutomo Suryo Wasisto and Kuwat Triyana},

url = {https://www.sciencedirect.com/science/article/abs/pii/S0026265X23008561},

doi = {https://doi.org/10.1016/j.microc.2023.109237},

year  = {2023},

date = {2023-10-01},

urldate = {2023-10-01},

journal = {Microchemical Journal},

pages = {109237},

publisher = {Elsevier},

abstract = {Various ammonia sensors based on different materials have continuously been developed and employed to enable real-time monitoring of ammonia gas in the environment. Efforts are put not only to improve their sensitivity and selectivity towards the target gas but also to operate them at room temperature. Here, we investigated the effect of overlaying maltodextrin with different concentrations on the surface of polyvinyl acetate (PVAc) nanofibers on ammonia sensing performances, in which quartz crystal microbalance (QCM) was utilized as a transducer to measure the resonance frequency shift affected by the adsorbed gas molecules. Higher concentrations of the overlaying maltodextrin led to larger nanofiber diameter and more functional active groups on the active nanofibrous layers. PVAc nanofibers with 0.05% maltodextrin overlay demonstrated the highest sensitivity of 0.525 Hz·ppm−1 at room temperature, which was 6.4 times higher than their bare counterpart (nanofiber without maltodextrin overlay). That sensor also possessed fast response and recovery times of 32 s and 17 s with a low detection limit (1.92 ppm). Besides its high reproducibility, reversibility, and repeatability, the sensor exhibited outstanding selectivity to other gas analytes and good long-term stability for 32 days of testing. This research shows that maltodextrin overlay can be used as a low-cost alternative route to increase the performance of organic material-based ammonia sensors, especially polymer nanofibers.},

key = {QCM, 10 MHz, QCM sensors, polyvinyl acetate, nanofibers, ammonia},

keywords = {10 MHz, Ammonia, Nanofibers, openQCM sensors, Polyvinyl acetate, QCM, Quartz Crystal Microbalance},

pubstate = {published},

tppubtype = {article}

}

@article{aflaha2022improving,

title = {Improving ammonia sensing performance of quartz crystal microbalance (QCM) coated with nanofibers and polyaniline (PANi) overlay},

author = {Rizky Aflaha and Henny Afiyanti and Zhafirah Nur Azizah and Hanif Khoirudin and Aditya Rianjanu and Ahmad Kusumaatmaja and Roto Roto and Kuwat Triyana},

url = {https://www.sciencedirect.com/science/article/pii/S2590137022001935},

doi = {https://doi.org/10.1016/j.biosx.2022.100300},

year  = {2022},

date = {2022-12-23},

urldate = {2022-01-01},

journal = {Biosensors and Bioelectronics: X},

pages = {100300},

publisher = {Elsevier},

abstract = {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.},

key = {Polyvinyl acetate, Polyaniline, Ammonia, Quartz crystal microbalance, Nanofiber},

keywords = {Ammonia, Nanofiber, Polyaniline, Polyvinyl acetate, Quartz Crystal Microbalance},

pubstate = {published},

tppubtype = {article}

}