openQCM – Powered by Novaetech S.r.l
Menu
Scientific Papers
Publications citing the applications of openQCM (by Novaetech S.r.l.) instruments and accessories in scientific research.
The list of scientific papers published on the most important journals showing the usage of openQCM in several scientific fields, such as thin film deposition, chemical sensors, biological research and biosensors.
Because of the large number of publications, we are reorganizing everything by subject areas. This will take some time. Thank you for your patience
2024
Prasetya, Nicholaus; Okur, Salih
Investigation of the Free-Base Zr-Porphyrin MOFs as Humidity Sensors for an Indoor Setting Journal Article
In: 2024.
Abstract | Links | BibTeX | Tags: Adsorption, humidity, openQCM, QCM, QCM sensor, Zr-porphyrin metal organic frameworks
@article{prasetya2024investigation,
title = {Investigation of the Free-Base Zr-Porphyrin MOFs as Humidity Sensors for an Indoor Setting},
author = {Nicholaus Prasetya and Salih Okur},
url = {https://chemrxiv.org/engage/chemrxiv/article-details/6608e3c466c138172950e040},
doi = {https://doi.org/10.26434/chemrxiv-2024-1jwr7},
year = {2024},
date = {2024-04-01},
urldate = {2024-04-01},
abstract = {Maintaining optimal relative humidity is paramount for human comfort. Therefore, the utilization of quartz crystal microbalance (QCM) as a humidity sensor platform holds significant promise due to its cost-effectiveness and high sensitivity. This study explores the efficacy of three free-base Zr porphyrin metal-organic frameworks (MOFs) - namely MOF-525, MOF-545, and NU-902 - as sensitive materials for QCM-based humidity sensors. Our extended experimental findings reveal that these materials exhibit notable sensitivity, particularly within relative humidity ranges of 40% to 100%. However, we observe potential irreversible adsorption sites within the MOF-545 framework, hindering its ability to revert to its initial state after prolonged exposure. In light of this observation, we conduct periodic cycling experiments at relative humidity levels of 40-70% to evaluate the measurement repeatability and feasibility of these sensors for indoor applications. Interestingly, the periodic cycling study demonstrates that MOF-545 shows promising repeatability, positioning it as a strong contender for indoor humidity sensing. In contrast, MOF-525 may necessitate extended desorption time, and NU-902 displays diminished sensitivity at low relative humidity levels. Nevertheless, a preliminary treatment of the MOF-545 QCM sensor may be necessary to address irreversible adsorption sites and uphold measurement repeatability, as only reversible adsorption sites are currently accessible. This study underscores the potential of MOF-based QCM sensors for effective humidity monitoring in indoor environments, thus facilitating improved comfort and environmental control.},
keywords = {Adsorption, humidity, openQCM, QCM, QCM sensor, Zr-porphyrin metal organic frameworks},
pubstate = {published},
tppubtype = {article}
}
Maintaining optimal relative humidity is paramount for human comfort. Therefore, the utilization of quartz crystal microbalance (QCM) as a humidity sensor platform holds significant promise due to its cost-effectiveness and high sensitivity. This study explores the efficacy of three free-base Zr porphyrin metal-organic frameworks (MOFs) - namely MOF-525, MOF-545, and NU-902 - as sensitive materials for QCM-based humidity sensors. Our extended experimental findings reveal that these materials exhibit notable sensitivity, particularly within relative humidity ranges of 40% to 100%. However, we observe potential irreversible adsorption sites within the MOF-545 framework, hindering its ability to revert to its initial state after prolonged exposure. In light of this observation, we conduct periodic cycling experiments at relative humidity levels of 40-70% to evaluate the measurement repeatability and feasibility of these sensors for indoor applications. Interestingly, the periodic cycling study demonstrates that MOF-545 shows promising repeatability, positioning it as a strong contender for indoor humidity sensing. In contrast, MOF-525 may necessitate extended desorption time, and NU-902 displays diminished sensitivity at low relative humidity levels. Nevertheless, a preliminary treatment of the MOF-545 QCM sensor may be necessary to address irreversible adsorption sites and uphold measurement repeatability, as only reversible adsorption sites are currently accessible. This study underscores the potential of MOF-based QCM sensors for effective humidity monitoring in indoor environments, thus facilitating improved comfort and environmental control.
Astier, Samuel; Johnson, Edwin C; Norvilaite, Oleta; Varlas, Spyridon; Brotherton, Emma E; Sanderson, George; Leggett, Graham J; Armes, Steven P
Controlling Adsorption of Diblock Copolymer Nanoparticles onto an Aldehyde-Functionalized Hydrophilic Polymer Brush via pH Modulation Journal Article
In: Langmuir, 2024.
Abstract | Links | BibTeX | Tags: Adsorption, Copolymers, nanoparticles, openQCM NEXT, QCM-D, Silicon, Solution chemistry
@article{astier2024controlling,
title = {Controlling Adsorption of Diblock Copolymer Nanoparticles onto an Aldehyde-Functionalized Hydrophilic Polymer Brush via pH Modulation},
author = {Samuel Astier and Edwin C Johnson and Oleta Norvilaite and Spyridon Varlas and Emma E Brotherton and George Sanderson and Graham J Leggett and Steven P Armes},
url = {https://pubs.acs.org/doi/full/10.1021/acs.langmuir.3c03392},
doi = {https://doi.org/10.1021/acs.langmuir.3c03392},
year = {2024},
date = {2024-02-06},
urldate = {2024-02-06},
journal = {Langmuir},
publisher = {ACS Publications},
abstract = {Sterically stabilized diblock copolymer nanoparticles with a well-defined spherical morphology and tunable diameter were prepared by RAFT aqueous emulsion polymerization of benzyl methacrylate at 70 °C. The steric stabilizer precursor used for these syntheses contained pendent cis-diol groups, which means that such nanoparticles can react with a suitable aldehyde-functional surface via acetal bond formation. This principle is examined herein by growing an aldehyde-functionalized polymer brush from a planar silicon wafer and studying the extent of nanoparticle adsorption onto this model substrate from aqueous solution at 25 °C using a quartz crystal microbalance (QCM). The adsorbed amount, Γ, depends on both the nanoparticle diameter and the solution pH, with minimal adsorption observed at pH 7 or 10 and substantial adsorption achieved at pH 4. Variable-temperature QCM studies provide strong evidence for chemical adsorption, while scanning electron microscopy images recorded for the nanoparticle-coated brush surface after drying indicate mean surface coverages of up to 62%. This fundamental study extends our understanding of the chemical adsorption of nanoparticles on soft substrates.},
keywords = {Adsorption, Copolymers, nanoparticles, openQCM NEXT, QCM-D, Silicon, Solution chemistry},
pubstate = {published},
tppubtype = {article}
}
Sterically stabilized diblock copolymer nanoparticles with a well-defined spherical morphology and tunable diameter were prepared by RAFT aqueous emulsion polymerization of benzyl methacrylate at 70 °C. The steric stabilizer precursor used for these syntheses contained pendent cis-diol groups, which means that such nanoparticles can react with a suitable aldehyde-functional surface via acetal bond formation. This principle is examined herein by growing an aldehyde-functionalized polymer brush from a planar silicon wafer and studying the extent of nanoparticle adsorption onto this model substrate from aqueous solution at 25 °C using a quartz crystal microbalance (QCM). The adsorbed amount, Γ, depends on both the nanoparticle diameter and the solution pH, with minimal adsorption observed at pH 7 or 10 and substantial adsorption achieved at pH 4. Variable-temperature QCM studies provide strong evidence for chemical adsorption, while scanning electron microscopy images recorded for the nanoparticle-coated brush surface after drying indicate mean surface coverages of up to 62%. This fundamental study extends our understanding of the chemical adsorption of nanoparticles on soft substrates.
Okur, Salih; Hashem, Tawheed; Bogdanova, Evgenia; Hodapp, Patrick; Heinke, Lars; Bräse, Stefan; Wöll, Christof
Optimized Detection of Volatile Organic Compounds Utilizing Durable and Selective Arrays of Tailored UiO-66-X SURMOF Sensors Journal Article
In: ACS sensors, 2024.
Abstract | Links | BibTeX | Tags: Adsorption, Liquids, Metal organic frameworks, openQCM Q-1, QCM-D, sensors, Volatile organic compounds
@article{okur2024optimized,
title = {Optimized Detection of Volatile Organic Compounds Utilizing Durable and Selective Arrays of Tailored UiO-66-X SURMOF Sensors},
author = {Salih Okur and Tawheed Hashem and Evgenia Bogdanova and Patrick Hodapp and Lars Heinke and Stefan Bräse and Christof Wöll},
url = {https://pubs.acs.org/doi/abs/10.1021/acssensors.3c01575},
doi = {https://doi.org/10.1021/acssensors.3c01575},
year = {2024},
date = {2024-02-06},
urldate = {2024-01-01},
journal = {ACS sensors},
publisher = {ACS Publications},
abstract = {Metal–organic frameworks (MOFs), with their well-defined and highly flexible nanoporous architectures, provide a material platform ideal for fabricating sensors. We demonstrate that the efficacy and specificity of detecting and differentiating volatile organic compounds (VOCs) can be significantly enhanced using a range of slightly varied MOFs. These variations are obtained via postsynthetic modification (PSM) of a primary framework. We alter the original MOF’s guest adsorption affinities by incorporating functional groups into the MOF linkers, which yields subtle changes in responses. These responses are subsequently evaluated by using machine learning (ML) techniques. Under severe conditions, such as high humidity and acidic environments, sensor stability and lifespan are of utmost importance. The UiO-66-X MOFs demonstrate the necessary durability in acidic, neutral, and basic environments with pH values ranging from 2 to 11, thus surpassing most other similar materials. The UiO-66-NH2 thin films were deposited on quartz-crystal microbalance (QCM) sensors in a high-temperature QCM liquid cell using a layer-by-layer pump method. Three different, highly stable surface-anchored MOFs (SURMOFs) of UiO-66-X obtained via the PSM approach (X: NH2, Cl, and N3) were employed to fabricate arrays suitable for electronic nose applications. These fabricated sensors were tested for their capability to distinguish between eight VOCs. Data from the sensor array were processed using three distinct ML techniques: linear discriminant (LDA), nearest neighbor (k-NN), and neural network analysis methods. The discrimination accuracies achieved were nearly 100% at high concentrations and over 95% at lower concentrations (50–100 ppm).},
keywords = {Adsorption, Liquids, Metal organic frameworks, openQCM Q-1, QCM-D, sensors, Volatile organic compounds},
pubstate = {published},
tppubtype = {article}
}
Metal–organic frameworks (MOFs), with their well-defined and highly flexible nanoporous architectures, provide a material platform ideal for fabricating sensors. We demonstrate that the efficacy and specificity of detecting and differentiating volatile organic compounds (VOCs) can be significantly enhanced using a range of slightly varied MOFs. These variations are obtained via postsynthetic modification (PSM) of a primary framework. We alter the original MOF’s guest adsorption affinities by incorporating functional groups into the MOF linkers, which yields subtle changes in responses. These responses are subsequently evaluated by using machine learning (ML) techniques. Under severe conditions, such as high humidity and acidic environments, sensor stability and lifespan are of utmost importance. The UiO-66-X MOFs demonstrate the necessary durability in acidic, neutral, and basic environments with pH values ranging from 2 to 11, thus surpassing most other similar materials. The UiO-66-NH2 thin films were deposited on quartz-crystal microbalance (QCM) sensors in a high-temperature QCM liquid cell using a layer-by-layer pump method. Three different, highly stable surface-anchored MOFs (SURMOFs) of UiO-66-X obtained via the PSM approach (X: NH2, Cl, and N3) were employed to fabricate arrays suitable for electronic nose applications. These fabricated sensors were tested for their capability to distinguish between eight VOCs. Data from the sensor array were processed using three distinct ML techniques: linear discriminant (LDA), nearest neighbor (k-NN), and neural network analysis methods. The discrimination accuracies achieved were nearly 100% at high concentrations and over 95% at lower concentrations (50–100 ppm).
2023
Malhotra, Jaskaran Singh; Reichert, Per Holger; Sundberg, Jonas
In: 2023 IEEE SENSORS, pp. 1–4, IEEE 2023.
Abstract | Links | BibTeX | Tags: Adsorption, analyte discrimination, BTEX sensor, Harmonic analysis, metal-organic frameworks, openQCM, QCM, Resonant frequency, Sensitivity, sensors, Stability analysis
@inproceedings{malhotra2023quartz,
title = {A Quartz Crystal Resonator Modified with a Metal-Organic Framework for Sensing of Benzene, Ethylbenzene, Toluene and Xylenes in Water},
author = {Jaskaran Singh Malhotra and Per Holger Reichert and Jonas Sundberg},
url = {https://ieeexplore.ieee.org/abstract/document/10325196},
doi = {https://doi.org/10.1109/SENSORS56945.2023.10325196},
year = {2023},
date = {2023-11-28},
urldate = {2023-11-28},
booktitle = {2023 IEEE SENSORS},
pages = {1--4},
organization = {IEEE},
abstract = {This work describes the use of a quartz crystal microbalance (QCM) based sensor for gravimetric sensing of benzene, toluene, ethylbenzene, and xylenes (BTEX). A film of a Cu-based metal-organic framework (MOF) capable of BTEX adsorption is deposited on the gold electrode of a quartz resonator (10 MHz). The sensor is operated under constant flow of water, simultaneously measuring frequency shifts in multiple harmonics. Introduction of BTEX compounds in the water shifts the frequency, enabling detection. Analysis of deviation in the 3 rd and 5 th harmonics enables discrimination of response from either of the BTEX molecules. The response time further enables understanding of diffusion kinetics of each molecule into the framework.},
keywords = {Adsorption, analyte discrimination, BTEX sensor, Harmonic analysis, metal-organic frameworks, openQCM, QCM, Resonant frequency, Sensitivity, sensors, Stability analysis},
pubstate = {published},
tppubtype = {inproceedings}
}
This work describes the use of a quartz crystal microbalance (QCM) based sensor for gravimetric sensing of benzene, toluene, ethylbenzene, and xylenes (BTEX). A film of a Cu-based metal-organic framework (MOF) capable of BTEX adsorption is deposited on the gold electrode of a quartz resonator (10 MHz). The sensor is operated under constant flow of water, simultaneously measuring frequency shifts in multiple harmonics. Introduction of BTEX compounds in the water shifts the frequency, enabling detection. Analysis of deviation in the 3 rd and 5 th harmonics enables discrimination of response from either of the BTEX molecules. The response time further enables understanding of diffusion kinetics of each molecule into the framework.
