@article{mahadi2025carbon,

title = {CARBON NANOTUBE-CHITOSAN THIN FILM ON QCM (QUARTZ CRYSTAL MICROBALANCE) FOR DETECTION OF IPA (ISOPROPYL ALCOHOL)},

author = {Aisyah Shafiqah Mahadi and Mohd Asyraf Mohd Razib and Aliza Aini Md Ralib and Farah Ahmad and Marmeezee Mohd Yusof},

url = {https://journals.iium.edu.my/bnrej/index.php/bnrej/article/view/123},

doi = {https://doi.org/10.31436/cnrej.v9i2.123},

year  = {2025},

date = {2025-12-28},

urldate = {2025-01-01},

journal = {Chemical and Natural Resources Engineering Journal (Formally known as Biological and Natural Resources Engineering Journal)},

volume = {9},

number = {2},

pages = {1–13},

abstract = {This study presents the development of a quartz crystal microbalance (QCM) sensor coated with a multi-walled carbon nanotube–chitosan (MWCNT-COOH/CS) composite for the detection of isopropyl (IPA) vapor, a common volatile organic compound (VOC). The composite was synthesized via glutaraldehyde crosslinking to enhance bonding between carboxyl-functionalized MWCNTs and chitosan, followed by sonication and stirring to ensure uniform dispersion. Material characterization was carried out using Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and field-emission scanning electron microscopy (FESEM), confirming successful integration and interaction between MWCNTs and CS. Static QCM analysis showed that the MWCNT-COOH/CS composite achieved a balanced frequency shift of approximately 106 Hz with a response time of ~40 seconds, outperforming standalone CS and MWCNT layers in terms of response speed and signal stability. Dynamic measurements across IPA concentrations from 300 to 700 ppm revealed a linear frequency shift trend with a correlation coefficient (R²) of 0.9713. Compared with similar sensors reported in the literature, the developed composite exhibits promising sensitivity, faster response time, and ease of fabrication, suggesting strong potential for real-time VOC monitoring applications.},

keywords = {Chitosan, IPA, MWCNTs (Multi-Walled Carbon Nanotubes), Nanocomposite sensor, openQCM, Quartz Crystal Microbalance (QCM)},

pubstate = {published},

tppubtype = {article}

}

@article{article,

title = {Multiwalled carbon nanotube/chitosan composite on quartz crystal microbalance for formaldehyde detection},

author = {Aisyah Mahadi and Mohd Razib and Aliza-Aini Md-Ralib and Farah Ahmad and Marmeezee Yusof},

url = {https://www.researchgate.net/publication/394351958_Multiwalled_carbon_nanotubechitosan_composite_on_quartz_crystal_microbalance_for_formaldehyde_detection},

doi = {10.11591/eei.v14i4.8948},

year  = {2025},

date = {2025-08-01},

urldate = {2025-08-01},

journal = {Bulletin of Electrical Engineering and Informatics},

volume = {14},

pages = {2638-2648},

keywords = {Chitosan, Multi-walled carbon nanotubes/chitosan, MWCNTs (Multi-Walled Carbon Nanotubes), openQCM Software, QCM, Quartz Crystal Microbalance, Volatile organic compounds},

pubstate = {published},

tppubtype = {article}

}

@article{as2024investigation,

title = {Investigation of the Multiple Doping of Citric Acid and Chitosan in Nanofiber for Enhancement of a Quartz Crystal Microbalance-Based Ammonia Sensor},

author = {Ahmad Hasan As’ ari and Rizky Aflaha and Laila Katriani and Ahmad Kusumaatmaja and Rike Yudianti and Kuwat Triyana},

url = {https://link.springer.com/article/10.1007/s11664-024-11646-0},

doi = {https://doi.org/10.1007/s11664-024-11646-0},

year  = {2024},

date = {2024-12-19},

urldate = {2024-12-19},

journal = {Journal of Electronic Materials},

pages = {1--13},

publisher = {Springer},

abstract = {Herein, the use of multiple doping of citric acid (CA) and chitosan (CS) in polyacrylonitrile (PAN) nanofibers over a quartz crystal microbalance is investigated as a method for enhancing the performance of an ammonia sensor at room temperature. It was found that the PAN/CA/CS sensor has superior sensitivity and better selectivity. The PAN/CA/CS sensor demonstrated sensitivity of (0.629 ± 0.005) Hz ppm−1, which increased by 2.75 times compared to the PAN/CA sensor and 39 times compared to the PAN sensor. Chitosan doping also resulted in better selectivity, as shown by the decreased response of the PAN/CA/CS sensor compared to the PAN/CA sensor to other analytes including formaldehyde (−147%), acetic acid (−22%), ethanol (−19%), methanol (−15%), and acetone (−1%). The viscoelastic properties of chitosan might be responsible for the anti-Sauerbrey phenomena behind the enhanced selectivity. The detection and adsorption mechanisms of the fabricated sensors towards ammonia were studied using adsorption kinetics and isotherms. The adsorption kinetics varied and exhibited the limits of the high-concentration region of each sensor. Moreover, all the fabricated sensors followed the Freundlich adsorption isotherm with different adsorption processes, which were confirmed by scanning electron microscopy, x-ray diffraction, and Fourier transform infrared spectroscopy concerning the morphology, crystal structure, and active groups after the loading of citric acid and chitosan. Thus, the use of multiple doping can improve the sensor abilities, as well as causing changes in the detection and adsorption mechanisms.},

keywords = {Adsorption, Ammonia, Chitosan, Nanofiber, openQCM, QCM, Quartz Crystal Microbalance},

pubstate = {published},

tppubtype = {article}

}

@article{KATRIANI2024111532,

title = {Nanofiber-coated quartz crystal microbalance with chitosan overlay for highly sensitive room temperature ammonia gas sensor},

author = {Laila Katriani and Rizky Aflaha and Ahmad Hasan As’ari and Pekik Nurwantoro and Roto Roto and Kuwat Triyana},

url = {https://www.sciencedirect.com/science/article/pii/S0026265X24016448},

doi = {https://doi.org/10.1016/j.microc.2024.111532},

issn = {0026-265X},

year  = {2024},

date = {2024-11-01},

urldate = {2024-11-01},

journal = {Microchemical Journal},

volume = {206},

pages = {111532},

abstract = {Ammonia is toxic and can pose health risks. Ensuring the safety of individuals working with or around ammonia sensors is crucial, adding complexity to the design and use of such sensors. An ammonia gas sensor by quartz crystal microbalance coated with chitosan-overlaid polyvinyl acetate (PVAc) nanofiber has been studied to have high performance in both sensitivity and selectivity. The scanning electron microscope (SEM) and Fourier-transform infrared (FTIR) spectroscopy were used to analyze the sensing surface, which was the electrospun PVAc nanofiber with chitosan overlay. The nanofiber showed a morphological change and had a more active layer after being overlaid by chitosan. The estimation of PVAc nanofiber thickness on the QCM sensor is (12.0 ± 2.1) µm, measured using a digital microscope. The QCM sensor deposited with PVAc nanofiber only had a sensitivity of 0.076 Hz·ppm−1. It improved to 3.012 Hz·ppm−1 after overlaid with 0.7 wt% chitosan (denoted as PVAc/Ch7 sensor), an increase of 39.6 times. Moreover, the PVAc/Ch7 sensor had a rapid response and recovery times of 9 and 35 s with a very low detection limit of 0.526 ppm. The sensor also exhibited good selectivity toward other analytes. In addition, the sensor also had outstanding in other performances, such as linearity, repeatability, reversibility, and excellent long-term stability. This proposed QCM-based ammonia sensor could be an alternative to analyzing ammonia in various fields.},

keywords = {Ammonia, Chitosan, Nanofiber, openq, openQCM sensors, PVAc, QCM},

pubstate = {published},

tppubtype = {article}

}