@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}

}

@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}

}