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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
Kunčák, Jakub; Forinová, Michala; Pilipenco, Alina; Procházka, Viktor; Horák, Petr; Dmitrievna, Sycheva Sofya; Deyneka, Ivan Gennadievich; Vaisocherová-L'isalová, Hana
In: Available at SSRN 4756321, 2024.
Abstract | Links | BibTeX | Tags: automatic data classification, Detection of pathogens, E. coli O157:H7, openQCM, openQCM Q-1, Point-of-care biosensors, Quartz Crystal Microbalance, SARS-CoV-2
@article{kunvcak2024automating,
title = {Automating Data Analysis for Point-of-Care Label-Free Surface-Based Affinity Biosensors Dealing with Complex Biological Samples: Escherichia Coli O157: H7 and Sars-Cov-2 Case Studies},
author = {Jakub Kunčák and Michala Forinová and Alina Pilipenco and Viktor Procházka and Petr Horák and Sycheva Sofya Dmitrievna and Ivan Gennadievich Deyneka and Hana Vaisocherová-L'isalová},
url = {https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4756321},
year = {2024},
date = {2024-03-20},
urldate = {2024-03-20},
journal = {Available at SSRN 4756321},
abstract = {Surface-based affinity biosensors offer a promising avenue for point-of-care (POC) detection of pathogens in real-world samples. While laboratory-based devices commonly employ various techniques to compensate for noise, signal drifts, fluidic artifacts, and other system imperfections, their POC counterparts aiming at providing simple cost-effective detection platforms for field use, often lack these qualities. This paper addresses this gap by introducing a procedure for automatic classification of pathogen presence in unprocessed liquids from direct detection data measured by a simple POC-relevant quartz crystal microbalance sensor device. By considering the nature of the sensor signal and the sources of its imperfections in real-world media, a straightforward procedure integrates “classical” analytical tools (filtering, data selection, baseline de-drifting, and result calculation) in successive steps to automate sample classification without the need for extensive machine learning. Through optimizing parameters using diverse datasets encompassing Escherichia coli O157:H7 (E. coli) and SARS-CoV-2 detection in various media including food-derived matrices and cell culture media, we achieved rates of successful detection as high as 80.8% and 90.9% for E. coli and SARS-CoV-2, respectively. Furthermore, we analyse the sensitivity of the routine to variations of input parameters and with examples discuss the key factors influencing the accuracy of the overall procedure. The results show that the developed method exhibits exceptional robustness across different biosensing assays and complex real-world media, highlighting its promising broader applicability in point-of-care diagnostics.},
keywords = {automatic data classification, Detection of pathogens, E. coli O157:H7, openQCM, openQCM Q-1, Point-of-care biosensors, Quartz Crystal Microbalance, SARS-CoV-2},
pubstate = {published},
tppubtype = {article}
}
Surface-based affinity biosensors offer a promising avenue for point-of-care (POC) detection of pathogens in real-world samples. While laboratory-based devices commonly employ various techniques to compensate for noise, signal drifts, fluidic artifacts, and other system imperfections, their POC counterparts aiming at providing simple cost-effective detection platforms for field use, often lack these qualities. This paper addresses this gap by introducing a procedure for automatic classification of pathogen presence in unprocessed liquids from direct detection data measured by a simple POC-relevant quartz crystal microbalance sensor device. By considering the nature of the sensor signal and the sources of its imperfections in real-world media, a straightforward procedure integrates “classical” analytical tools (filtering, data selection, baseline de-drifting, and result calculation) in successive steps to automate sample classification without the need for extensive machine learning. Through optimizing parameters using diverse datasets encompassing Escherichia coli O157:H7 (E. coli) and SARS-CoV-2 detection in various media including food-derived matrices and cell culture media, we achieved rates of successful detection as high as 80.8% and 90.9% for E. coli and SARS-CoV-2, respectively. Furthermore, we analyse the sensitivity of the routine to variations of input parameters and with examples discuss the key factors influencing the accuracy of the overall procedure. The results show that the developed method exhibits exceptional robustness across different biosensing assays and complex real-world media, highlighting its promising broader applicability in point-of-care diagnostics.
Sehit, Ekin; Yao, Guiyang; Battocchio, Giovanni; Radfar, Rahil; Trimpert, Jakob; Mroginski, Maria A; Süssmuth, Roderich; Altintas, Zeynep
In: ACS sensors, 2024.
Abstract | Links | BibTeX | Tags: Antigens, Drinking water, epitope imprinting, in silico-designed epitope-mediated adenovirus receptors, molecular dynamics, Monomers, openQCM Q-1, QCM, QCM sensor, Receptors, sensors, virus detection
@article{sehit2024computationally,
title = {Computationally Designed Epitope-Mediated Imprinted Polymers versus Conventional Epitope Imprints for the Detection of Human Adenovirus in Water and Human Serum Samples},
author = {Ekin Sehit and Guiyang Yao and Giovanni Battocchio and Rahil Radfar and Jakob Trimpert and Maria A Mroginski and Roderich Süssmuth and Zeynep Altintas},
url = {https://pubs.acs.org/doi/full/10.1021/acssensors.3c02374},
doi = {https://doi.org/10.1021/acssensors.3c02374},
year = {2024},
date = {2024-03-15},
urldate = {2024-03-15},
journal = {ACS sensors},
publisher = {ACS Publications},
abstract = {Detection of pathogenic viruses for point-of-care applications has attracted great attention since the COVID-19 pandemic. Current virus diagnostic tools are laborious and expensive, while requiring medically trained staff. Although user-friendly and cost-effective biosensors are utilized for virus detection, many of them rely on recognition elements that suffer major drawbacks. Herein, computationally designed epitope-imprinted polymers (eIPs) are conjugated with a portable piezoelectric sensing platform to establish a sensitive and robust biosensor for the human pathogenic adenovirus (HAdV). The template epitope is selected from the knob part of the HAdV capsid, ensuring surface accessibility. Computational simulations are performed to evaluate the conformational stability of the selected epitope. Further, molecular dynamics simulations are executed to investigate the interactions between the epitope and the different functional monomers for the smart design of eIPs. The HAdV epitope is imprinted via the solid-phase synthesis method to produce eIPs using in silico-selected ingredients. The synthetic receptors show a remarkable detection sensitivity (LOD: 102 pfu mL–1) and affinity (dissociation constant (Kd): 6.48 × 10–12 M) for HAdV. Moreover, the computational eIPs lead to around twofold improved binding behavior than the eIPs synthesized with a well-established conventional recipe. The proposed computational strategy holds enormous potential for the intelligent design of ultrasensitive imprinted polymer binders.},
keywords = {Antigens, Drinking water, epitope imprinting, in silico-designed epitope-mediated adenovirus receptors, molecular dynamics, Monomers, openQCM Q-1, QCM, QCM sensor, Receptors, sensors, virus detection},
pubstate = {published},
tppubtype = {article}
}
Detection of pathogenic viruses for point-of-care applications has attracted great attention since the COVID-19 pandemic. Current virus diagnostic tools are laborious and expensive, while requiring medically trained staff. Although user-friendly and cost-effective biosensors are utilized for virus detection, many of them rely on recognition elements that suffer major drawbacks. Herein, computationally designed epitope-imprinted polymers (eIPs) are conjugated with a portable piezoelectric sensing platform to establish a sensitive and robust biosensor for the human pathogenic adenovirus (HAdV). The template epitope is selected from the knob part of the HAdV capsid, ensuring surface accessibility. Computational simulations are performed to evaluate the conformational stability of the selected epitope. Further, molecular dynamics simulations are executed to investigate the interactions between the epitope and the different functional monomers for the smart design of eIPs. The HAdV epitope is imprinted via the solid-phase synthesis method to produce eIPs using in silico-selected ingredients. The synthetic receptors show a remarkable detection sensitivity (LOD: 102 pfu mL–1) and affinity (dissociation constant (Kd): 6.48 × 10–12 M) for HAdV. Moreover, the computational eIPs lead to around twofold improved binding behavior than the eIPs synthesized with a well-established conventional recipe. The proposed computational strategy holds enormous potential for the intelligent design of ultrasensitive imprinted polymer binders.
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).
Chen, Xie
QCM anal`yza nanočástic a molekul Masters Thesis
České vysoké učen'i technické v Praze. Vypočetn'i a informačn'i centrum., 2024.
Abstract | Links | BibTeX | Tags: Cortisol, nanodiamonds, nanoparticles, openQCM Q-1, QCM-D, Quartz Crystal Microbalance
@mastersthesis{chen2024qcm,
title = {QCM anal`yza nanočástic a molekul},
author = {Xie Chen},
url = {https://dspace.cvut.cz/handle/10467/113400},
year = {2024},
date = {2024-01-22},
urldate = {2024-01-22},
school = {České vysoké učen'i technické v Praze. Vypočetn'i a informačn'i centrum.},
abstract = {Sensors based on quartz crystal microbalances (QCM) have dominated research in recent years. They have produced excellent laboratory results in analyzing the mass as well as the conformation of nanoparticles and molecules. The technology is constantly developed and widely used in various fields of chemistry, physics and biology. Here, we investigated a novel concept based on the use of nanodiamonds on QCM and explored the performance of nanodiamonds on QCM sensors, which helps in expanding the application of nanodiamonds in biosensing and exploring their effectiveness in QCM setups. We established a procedure and suitable parameters for the QCM sensor measurement. 5 MHz opensource QCM sensor system was used for building up the sensor assay for detection of cortisol via antigen (Ag)-antibody (Ab) reactions. Optical pictures after each functionalization step as well as scanning electron microscopy (SEM) pictures before and after the experiment were observed and compared. The values of amplitude, phase, resonance frequency, and dissipation were acquired in dry and water environment. The main evaluated QCM parameters were changes in resonance frequency (Δf) and simultaneous changes in QCM energy dissipation (ΔD), corresponding to changes in mass and morphology of the investigated sensor structure. Thereby we identified sensor assay build up, its functioning in dry and water conditions as well as potential issues such as partial release of nanodiamonds during the chemical treatments.
Sensors based on quartz crystal microbalances (QCM) have dominated research in recent years. They have produced excellent laboratory results in analyzing the mass as well as the conformation of nanoparticles and molecules. The technology is constantly developed and widely used in various fields of chemistry, physics and biology. Here, we investigated a novel concept based on the use of nanodiamonds on QCM and explored the performance of nanodiamonds on QCM sensors, which helps in expanding the application of nanodiamonds in biosensing and exploring their effectiveness in QCM setups. We established a procedure and suitable parameters for the QCM sensor measurement. 5 MHz opensource QCM sensor system was used for building up the sensor assay for detection of cortisol via antigen (Ag)-antibody (Ab) reactions. Optical pictures after each functionalization step as well as scanning electron microscopy (SEM) pictures before and after the experiment were observed and compared. The values of amplitude, phase, resonance frequency, and dissipation were acquired in dry and water environment. The main evaluated QCM parameters were changes in resonance frequency (Δf) and simultaneous changes in QCM energy dissipation (ΔD), corresponding to changes in mass and morphology of the investigated sensor structure. Thereby we identified sensor assay build up, its functioning in dry and water conditions as well as potential issues such as partial release of nanodiamonds during the chemical treatments.},
keywords = {Cortisol, nanodiamonds, nanoparticles, openQCM Q-1, QCM-D, Quartz Crystal Microbalance},
pubstate = {published},
tppubtype = {mastersthesis}
}
Sensors based on quartz crystal microbalances (QCM) have dominated research in recent years. They have produced excellent laboratory results in analyzing the mass as well as the conformation of nanoparticles and molecules. The technology is constantly developed and widely used in various fields of chemistry, physics and biology. Here, we investigated a novel concept based on the use of nanodiamonds on QCM and explored the performance of nanodiamonds on QCM sensors, which helps in expanding the application of nanodiamonds in biosensing and exploring their effectiveness in QCM setups. We established a procedure and suitable parameters for the QCM sensor measurement. 5 MHz opensource QCM sensor system was used for building up the sensor assay for detection of cortisol via antigen (Ag)-antibody (Ab) reactions. Optical pictures after each functionalization step as well as scanning electron microscopy (SEM) pictures before and after the experiment were observed and compared. The values of amplitude, phase, resonance frequency, and dissipation were acquired in dry and water environment. The main evaluated QCM parameters were changes in resonance frequency (Δf) and simultaneous changes in QCM energy dissipation (ΔD), corresponding to changes in mass and morphology of the investigated sensor structure. Thereby we identified sensor assay build up, its functioning in dry and water conditions as well as potential issues such as partial release of nanodiamonds during the chemical treatments.
Sensors based on quartz crystal microbalances (QCM) have dominated research in recent years. They have produced excellent laboratory results in analyzing the mass as well as the conformation of nanoparticles and molecules. The technology is constantly developed and widely used in various fields of chemistry, physics and biology. Here, we investigated a novel concept based on the use of nanodiamonds on QCM and explored the performance of nanodiamonds on QCM sensors, which helps in expanding the application of nanodiamonds in biosensing and exploring their effectiveness in QCM setups. We established a procedure and suitable parameters for the QCM sensor measurement. 5 MHz opensource QCM sensor system was used for building up the sensor assay for detection of cortisol via antigen (Ag)-antibody (Ab) reactions. Optical pictures after each functionalization step as well as scanning electron microscopy (SEM) pictures before and after the experiment were observed and compared. The values of amplitude, phase, resonance frequency, and dissipation were acquired in dry and water environment. The main evaluated QCM parameters were changes in resonance frequency (Δf) and simultaneous changes in QCM energy dissipation (ΔD), corresponding to changes in mass and morphology of the investigated sensor structure. Thereby we identified sensor assay build up, its functioning in dry and water conditions as well as potential issues such as partial release of nanodiamonds during the chemical treatments.
Sensors based on quartz crystal microbalances (QCM) have dominated research in recent years. They have produced excellent laboratory results in analyzing the mass as well as the conformation of nanoparticles and molecules. The technology is constantly developed and widely used in various fields of chemistry, physics and biology. Here, we investigated a novel concept based on the use of nanodiamonds on QCM and explored the performance of nanodiamonds on QCM sensors, which helps in expanding the application of nanodiamonds in biosensing and exploring their effectiveness in QCM setups. We established a procedure and suitable parameters for the QCM sensor measurement. 5 MHz opensource QCM sensor system was used for building up the sensor assay for detection of cortisol via antigen (Ag)-antibody (Ab) reactions. Optical pictures after each functionalization step as well as scanning electron microscopy (SEM) pictures before and after the experiment were observed and compared. The values of amplitude, phase, resonance frequency, and dissipation were acquired in dry and water environment. The main evaluated QCM parameters were changes in resonance frequency (Δf) and simultaneous changes in QCM energy dissipation (ΔD), corresponding to changes in mass and morphology of the investigated sensor structure. Thereby we identified sensor assay build up, its functioning in dry and water conditions as well as potential issues such as partial release of nanodiamonds during the chemical treatments.
2023
Javadzadehkalkhoran, Majid; Trabzon, Levent
Preparation and Characterization of Affordable Experimental Sensors Array for Particulate Matter Sensing Journal Article
In: 2023.
Abstract | Links | BibTeX | Tags: openQCM, openQCM Q-1, Particulate matter, PM generator, PM test setup, QCM, QCM sensor, Sensor array
@article{javadzadehkalkhoran2023preparation,
title = {Preparation and Characterization of Affordable Experimental Sensors Array for Particulate Matter Sensing},
author = {Majid Javadzadehkalkhoran and Levent Trabzon},
url = {https://www.researchsquare.com/article/rs-3654975/v1},
doi = {https://doi.org/10.21203/rs.3.rs-3654975/v1},
year = {2023},
date = {2023-12-06},
urldate = {2023-12-06},
abstract = {Interest for particulate matter (PM) sensors has increased significantly during last decade. Having a proper experimental setup to test these sensors is necessary. Most of the devices that are used in the PM test setups for both PM generating and measuring are bulky and expensive. In this study a cost-effective experimental setup has been designed with a custom made PM generator and small size laser and quartz crystal microbalance (QCM) sensors. The generator has the capability of producing PM from three different sources: dry powder, liquid suspension and combustion. The QCM completes the weakness of small laser sensors for sensing the ultra-fine particles. Moreover, performance of the QCM sensor has been investigated with different PM sources and different ambient conditions. It has been found that the response of QCM could be affected from PM source and ambient condition. The change in PM composition and size causes notable impact on QCM response. Relative humidity (RH) also could change the sensor response up to 22%. While changing the temperature of the flow has not significant effect on QCM response, increasing the temperature from 25°C to 30°C caused 12% change in QCM response in grease-coated one. The QCM sensor has the best response with small size smoke PM’s with lowest effect from ambient conditions.},
keywords = {openQCM, openQCM Q-1, Particulate matter, PM generator, PM test setup, QCM, QCM sensor, Sensor array},
pubstate = {published},
tppubtype = {article}
}
Interest for particulate matter (PM) sensors has increased significantly during last decade. Having a proper experimental setup to test these sensors is necessary. Most of the devices that are used in the PM test setups for both PM generating and measuring are bulky and expensive. In this study a cost-effective experimental setup has been designed with a custom made PM generator and small size laser and quartz crystal microbalance (QCM) sensors. The generator has the capability of producing PM from three different sources: dry powder, liquid suspension and combustion. The QCM completes the weakness of small laser sensors for sensing the ultra-fine particles. Moreover, performance of the QCM sensor has been investigated with different PM sources and different ambient conditions. It has been found that the response of QCM could be affected from PM source and ambient condition. The change in PM composition and size causes notable impact on QCM response. Relative humidity (RH) also could change the sensor response up to 22%. While changing the temperature of the flow has not significant effect on QCM response, increasing the temperature from 25°C to 30°C caused 12% change in QCM response in grease-coated one. The QCM sensor has the best response with small size smoke PM’s with lowest effect from ambient conditions.
Stuart, Daniel David
Advancing Label Free Detection Techniques Through Surface Based Sensing and Machine Learning PhD Thesis
University of California, Riverside, 2023.
Abstract | Links | BibTeX | Tags: openQCM, openQCM Q-1, QCM, QCM sensor, QCM-D, SARS-CoV-2
@phdthesis{stuart2023advancing,
title = {Advancing Label Free Detection Techniques Through Surface Based Sensing and Machine Learning},
author = {Daniel David Stuart},
url = {https://escholarship.org/uc/item/2cr290xf},
year = {2023},
date = {2023-12-01},
urldate = {2023-12-01},
school = {University of California, Riverside},
abstract = {High-performing sensors have played a pivotal role in expanding our understanding of biological systems, disease diagnosis, environmental monitoring, and national security. The technical capability they provide has enabled us to obtain in-depth information and insights towards improving human health. One area of sensing that exemplifies this progress is the development of label free sensors which allow direct analysis of molecular interactions. Among these methods surface plasmon resonance (SPR) has emerged as a powerful, real-time detection technique for studies of biological interactions, drug discovery, and other important aspects that lead to new disease diagnosis. Through the implementation of new materials and methods SPR and other label-free sensors have expanded the range of analytes tested. This Dissertation aims to establish improvements in materials and methodologies through technology advancement for solving current sensor limitations. The work focuses on enhancing sensing signal while limiting the impact of nonspecific interactions on label-free methods, providing expanded molecular identity information, and overcoming challenges encountered when detecting small molecules. Chapters 2, 3, and 4 demonstrate advancements in unique biomimetic surfaces to enable the exploration of new biological systems as well as block nonspecific interactions. Chapter 2 focuses on a tethered membrane system to promote incorporation of relevant constituents into lipid bilayers without compromising membrane mobility property and drug delivery interactions. Chapter 3 employs a charged membrane to suppress nonspecific interactions and explores the working mechanism. Chapter 4 expands the capabilities of label-free sensing systems through development of curved membrane platforms that mitigate the decay limits through modeling of lipid distribution in vesicles. Chapter 5 exploits the plasmonic properties of SPR chips to enhance signals in matrix assisted laser desorption ionization mass spectrometry (MALDI-MS) , which is further facilitated with development of machine learning models to identify bacterial species. In Chapter 6, the limitation of small molecule analysis with SPR is tackled by taking advantage of pressure effects to provide specific gas sensing. Each of these Chapters provides novel advancements in sensing capabilities by addressing performance-impairing limitations in label-free sensors. Research goals are achieved both from improvements to SPR systems and incorporation of other methodologies to augment SPR results.},
keywords = {openQCM, openQCM Q-1, QCM, QCM sensor, QCM-D, SARS-CoV-2},
pubstate = {published},
tppubtype = {phdthesis}
}
High-performing sensors have played a pivotal role in expanding our understanding of biological systems, disease diagnosis, environmental monitoring, and national security. The technical capability they provide has enabled us to obtain in-depth information and insights towards improving human health. One area of sensing that exemplifies this progress is the development of label free sensors which allow direct analysis of molecular interactions. Among these methods surface plasmon resonance (SPR) has emerged as a powerful, real-time detection technique for studies of biological interactions, drug discovery, and other important aspects that lead to new disease diagnosis. Through the implementation of new materials and methods SPR and other label-free sensors have expanded the range of analytes tested. This Dissertation aims to establish improvements in materials and methodologies through technology advancement for solving current sensor limitations. The work focuses on enhancing sensing signal while limiting the impact of nonspecific interactions on label-free methods, providing expanded molecular identity information, and overcoming challenges encountered when detecting small molecules. Chapters 2, 3, and 4 demonstrate advancements in unique biomimetic surfaces to enable the exploration of new biological systems as well as block nonspecific interactions. Chapter 2 focuses on a tethered membrane system to promote incorporation of relevant constituents into lipid bilayers without compromising membrane mobility property and drug delivery interactions. Chapter 3 employs a charged membrane to suppress nonspecific interactions and explores the working mechanism. Chapter 4 expands the capabilities of label-free sensing systems through development of curved membrane platforms that mitigate the decay limits through modeling of lipid distribution in vesicles. Chapter 5 exploits the plasmonic properties of SPR chips to enhance signals in matrix assisted laser desorption ionization mass spectrometry (MALDI-MS) , which is further facilitated with development of machine learning models to identify bacterial species. In Chapter 6, the limitation of small molecule analysis with SPR is tackled by taking advantage of pressure effects to provide specific gas sensing. Each of these Chapters provides novel advancements in sensing capabilities by addressing performance-impairing limitations in label-free sensors. Research goals are achieved both from improvements to SPR systems and incorporation of other methodologies to augment SPR results.
Forinová, Michala; Seidlová, Anna; Pilipenco, Alina; Jr, N Scott Lynn; Obořilová, Radka; Farka, Zdeněk; Skládal, Petr; Saláková, Alena; Spasovová, Monika; Houska, Milan; others,
In: Current Research in Biotechnology, pp. 100166, 2023.
Abstract | Links | BibTeX | Tags: Antifouling coating, biosensors, Cultivation-based methods, openQCM Q-1, QCM-D, Quartz Crystal Microbalance, S. aureus
@article{forinova2023comparative,
title = {A Comparative Assessment of a Piezoelectric Biosensor Based on a New Antifouling Nanolayer and Cultivation Methods: Enhancing S. aureus Detection in Fresh Dairy Products},
author = {Michala Forinová and Anna Seidlová and Alina Pilipenco and N Scott Lynn Jr and Radka Obořilová and Zdeněk Farka and Petr Skládal and Alena Saláková and Monika Spasovová and Milan Houska and others},
url = {https://www.sciencedirect.com/science/article/pii/S2590262823000485},
doi = {https://doi.org/10.1016/j.crbiot.2023.100166},
year = {2023},
date = {2023-11-23},
urldate = {2023-11-23},
journal = {Current Research in Biotechnology},
pages = {100166},
publisher = {Elsevier},
abstract = {Ensuring dairy product safety demands rapid and precise Staphylococcus aureus (S. aureus) detection. Biosensors show promise, but their performance is often demonstrated in model samples using non-native pathogens and has never been studied towards S. aureus detection in naturally contaminated samples. This study addresses the gap by directly comparing results taken with a novel piezoelectric biosensor, capable of one-step detection, with four conventional cultivation-based methods. Our findings reveal that this biosensor, based on an antifouling nanolayer-coated biochip, exhibits exceptional resistance to biofouling from unprocessed dairy products and is further capable of specific S. aureus detection. Notably, it performed comparably to Petrifilm and Baird-Parker methods but delivered results in only 30 min, bringing a substantial reduction from the 24 h required by cultivation-based techniques. Our study also highlights differences in the performance of cultivation methods when analyzing artificially spiked versus naturally contaminated foods. These findings underline the potential of antifouling biosensors as efficient reliable tools for rapid, cost-effective, point-of-care testing, enhancing fresh dairy product safety and S. aureus detection.},
keywords = {Antifouling coating, biosensors, Cultivation-based methods, openQCM Q-1, QCM-D, Quartz Crystal Microbalance, S. aureus},
pubstate = {published},
tppubtype = {article}
}
Ensuring dairy product safety demands rapid and precise Staphylococcus aureus (S. aureus) detection. Biosensors show promise, but their performance is often demonstrated in model samples using non-native pathogens and has never been studied towards S. aureus detection in naturally contaminated samples. This study addresses the gap by directly comparing results taken with a novel piezoelectric biosensor, capable of one-step detection, with four conventional cultivation-based methods. Our findings reveal that this biosensor, based on an antifouling nanolayer-coated biochip, exhibits exceptional resistance to biofouling from unprocessed dairy products and is further capable of specific S. aureus detection. Notably, it performed comparably to Petrifilm and Baird-Parker methods but delivered results in only 30 min, bringing a substantial reduction from the 24 h required by cultivation-based techniques. Our study also highlights differences in the performance of cultivation methods when analyzing artificially spiked versus naturally contaminated foods. These findings underline the potential of antifouling biosensors as efficient reliable tools for rapid, cost-effective, point-of-care testing, enhancing fresh dairy product safety and S. aureus detection.
Armutcu, Canan; Karasu, Tunca; Pişkin, Sena; Özgür, Erdoğan; Uzun, Lokman
Selective Aptasensor for Trinitrotoluene Detection: Comparison of the Detecting Performances from Liquid and Vapor Phases Journal Article
In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, pp. 132258, 2023.
Abstract | Links | BibTeX | Tags: aptasensor, explosive detection, openQCM Q-1, openQCM sensors, QCM-D, TNT
@article{armutcu2023selective,
title = {Selective Aptasensor for Trinitrotoluene Detection: Comparison of the Detecting Performances from Liquid and Vapor Phases},
author = {Canan Armutcu and Tunca Karasu and Sena Pişkin and Erdoğan Özgür and Lokman Uzun},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0927775723013420},
doi = {https://doi.org/10.1016/j.colsurfa.2023.132258},
year = {2023},
date = {2023-11-05},
urldate = {2023-11-05},
journal = {Colloids and Surfaces A: Physicochemical and Engineering Aspects},
pages = {132258},
publisher = {Elsevier},
abstract = {In general, chromatographic and sensor analyses have been utilized for explosive detection. The main interest on those systems is to develop a method to selectively detect explosives at a single step as well as from vapor phase if possible. Moreover, on-site and real-time detection with portable systems is another challenge for the researchers. On the other hand, the detection of 2,4,6-trinitrotoluene (TNT) vapor at the crime scene, preferably before the explosion is highly demanded in order to prevent the negative effects of terrorism and to ensure the safety of the civilian population. In this study, initially, Quartz Crystal Microbalance (QCM) sensor was prepared for real-time monitoring of TNT in aqueous solution, through the attachment of TNT peptide aptamer on the gold surface of QCM sensor. Secondly, after providing optimum conditions, TNT detection was investigated even from vapor phase through the QCM aptasensor. According to results, the selectivity coefficient of QCM-based aptasensor was calculated as 6.78 for TNT in respect to DNT whereas that was calculated as 9.02 for TNT in respect to TNB. In addition, the evaluation of the reusability and storage stability emphasized that the sensor could be used repeatedly without significant reduction in dissipation (∆D) values. The linearity coefficient (R2) was found to be 0.9965. The limit of detection (LOD) and the limit of quantitation (LOQ) were determined as 0.0238 and 0.0739 nM, respectively. The studies demonstrated that the portable QCM sensor decorated with the aptamer selective for TNT molecules could be classified as a promising alternative, selective, cost-friendly, easy-to-prepare, ready-to-use, and applicable for on-site and real-time explosive measurements (even from vapor phase).},
key = {openQCM Q-1, QCM-D, openQCM sensors, explosive detection, TNT, aptasensor},
keywords = {aptasensor, explosive detection, openQCM Q-1, openQCM sensors, QCM-D, TNT},
pubstate = {published},
tppubtype = {article}
}
In general, chromatographic and sensor analyses have been utilized for explosive detection. The main interest on those systems is to develop a method to selectively detect explosives at a single step as well as from vapor phase if possible. Moreover, on-site and real-time detection with portable systems is another challenge for the researchers. On the other hand, the detection of 2,4,6-trinitrotoluene (TNT) vapor at the crime scene, preferably before the explosion is highly demanded in order to prevent the negative effects of terrorism and to ensure the safety of the civilian population. In this study, initially, Quartz Crystal Microbalance (QCM) sensor was prepared for real-time monitoring of TNT in aqueous solution, through the attachment of TNT peptide aptamer on the gold surface of QCM sensor. Secondly, after providing optimum conditions, TNT detection was investigated even from vapor phase through the QCM aptasensor. According to results, the selectivity coefficient of QCM-based aptasensor was calculated as 6.78 for TNT in respect to DNT whereas that was calculated as 9.02 for TNT in respect to TNB. In addition, the evaluation of the reusability and storage stability emphasized that the sensor could be used repeatedly without significant reduction in dissipation (∆D) values. The linearity coefficient (R2) was found to be 0.9965. The limit of detection (LOD) and the limit of quantitation (LOQ) were determined as 0.0238 and 0.0739 nM, respectively. The studies demonstrated that the portable QCM sensor decorated with the aptamer selective for TNT molecules could be classified as a promising alternative, selective, cost-friendly, easy-to-prepare, ready-to-use, and applicable for on-site and real-time explosive measurements (even from vapor phase).
Neville, George M; Dobre, Ana-Maria; Smith, Gavin J; Micciulla, Samantha; Brooks, Nick J; Arnold, Thomas; Welton, Tom; Edler, Karen J
Interactions of Choline and Geranate (CAGE) and Choline Octanoate (CAOT) Deep Eutectic Solvents with Lipid Bilayers Journal Article
In: Advanced Functional Materials, pp. 2306644, 2023.
Abstract | Links | BibTeX | Tags: Choline, Choline Octanoate, geranic acid, openQCM Q-1, QCM, QCM-D
@article{neville2023interactions,
title = {Interactions of Choline and Geranate (CAGE) and Choline Octanoate (CAOT) Deep Eutectic Solvents with Lipid Bilayers},
author = {George M Neville and Ana-Maria Dobre and Gavin J Smith and Samantha Micciulla and Nick J Brooks and Thomas Arnold and Tom Welton and Karen J Edler},
url = {https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.202306644},
doi = {https://doi.org/10.1002/adfm.202306644},
year = {2023},
date = {2023-10-02},
urldate = {2023-10-02},
journal = {Advanced Functional Materials},
pages = {2306644},
publisher = {Wiley Online Library},
abstract = {Aerosols and films are found in indoor and outdoor environments. How they interact with pollutants, such as ozone, has a direct impact on our environment via cloud droplet formation and the chemical persistence of toxic aerosol constituents. The chemical reactivity of aerosol emissions is typically measured spectroscopically or by techniques such as mass spectrometry, directly monitoring the amount of material during a chemical reaction. We present a study which indirectly measures oxidation kinetics in a common cooking aerosol proxy using a low-cost quartz crystal microbalance with dissipation monitoring (QCM-D). We validated this approach by comparison with kinetics measured both spectroscopically and with high-intensity synchrotron radiation. Using microscopy, we found that the film morphology changed and film rigidity increased during oxidation. There was evidence of surface crust formation on oxidised particles, though this was not consistent for all experiments. Crucially, our kinetic modelling of these experimental data confirmed that the oleic acid decay rate is in line with previous literature determinations, which demonstrates that performing such experiments on a QCM-D does not alter the underlying mechanism. There is clear potential to take this robust and low-cost but sensitive method to the field for in situ monitoring of reactions outdoors and indoors.},
key = {Choline, Choline Octanoate, geranic acid, openQCM Q-1, QCM, QCM-D},
keywords = {Choline, Choline Octanoate, geranic acid, openQCM Q-1, QCM, QCM-D},
pubstate = {published},
tppubtype = {article}
}
Aerosols and films are found in indoor and outdoor environments. How they interact with pollutants, such as ozone, has a direct impact on our environment via cloud droplet formation and the chemical persistence of toxic aerosol constituents. The chemical reactivity of aerosol emissions is typically measured spectroscopically or by techniques such as mass spectrometry, directly monitoring the amount of material during a chemical reaction. We present a study which indirectly measures oxidation kinetics in a common cooking aerosol proxy using a low-cost quartz crystal microbalance with dissipation monitoring (QCM-D). We validated this approach by comparison with kinetics measured both spectroscopically and with high-intensity synchrotron radiation. Using microscopy, we found that the film morphology changed and film rigidity increased during oxidation. There was evidence of surface crust formation on oxidised particles, though this was not consistent for all experiments. Crucially, our kinetic modelling of these experimental data confirmed that the oleic acid decay rate is in line with previous literature determinations, which demonstrates that performing such experiments on a QCM-D does not alter the underlying mechanism. There is clear potential to take this robust and low-cost but sensitive method to the field for in situ monitoring of reactions outdoors and indoors.
Neville, George; Dobre, Ana-Maria; Smith, Gavin; Micciulla, Samantha; Brooks, Nick; Arnold, Thomas; Welton, Tom; Edler, Karen
Dataset for Journal Article
In: 2023.
Abstract | Links | BibTeX | Tags: deep eutectic solvents, ionic liquids, lipid bilayers, neutron reflectivity, neutron scattering, openQCM Q-1, QCM, transdermal delivery
@article{neville2023dataset,
title = {Dataset for},
author = {George Neville and Ana-Maria Dobre and Gavin Smith and Samantha Micciulla and Nick Brooks and Thomas Arnold and Tom Welton and Karen Edler},
url = {https://researchdata.bath.ac.uk/1289/},
doi = {https://doi.org/10.15125/BATH-01289},
year = {2023},
date = {2023-10-02},
urldate = {2023-10-02},
publisher = {University of Bath},
abstract = {Deep eutectic solvents (DES) and ionic liquids (ILs) are often amphiphilic and interact with phospholipid membranes. Mixtures between choline and gernanic acid, coined 'CAGE', have been found to facilitate the transdermal delivery of larger pharmaceuticals, such as insulin. However, little is known about its mechanism of activity. The purpose for obtaining this data was to characterise aqueous suspensions of choline and germanic acid (CAGE) and choline and octanoic acid (CAOT) and compare their interactions with solid-supported lipid bilayers and vesicle layers. Particularly, dynamic light scattering (DLS) and quartz crystal microbalance with dissipation (QCM-D) measurements were used alongside neutron reflectivity (NR) to evaluate any structure-function relationships contributing to the DES behaviour, aiming towards the rational design of neoteric solvents for transdermal delivery.},
keywords = {deep eutectic solvents, ionic liquids, lipid bilayers, neutron reflectivity, neutron scattering, openQCM Q-1, QCM, transdermal delivery},
pubstate = {published},
tppubtype = {article}
}
Deep eutectic solvents (DES) and ionic liquids (ILs) are often amphiphilic and interact with phospholipid membranes. Mixtures between choline and gernanic acid, coined 'CAGE', have been found to facilitate the transdermal delivery of larger pharmaceuticals, such as insulin. However, little is known about its mechanism of activity. The purpose for obtaining this data was to characterise aqueous suspensions of choline and germanic acid (CAGE) and choline and octanoic acid (CAOT) and compare their interactions with solid-supported lipid bilayers and vesicle layers. Particularly, dynamic light scattering (DLS) and quartz crystal microbalance with dissipation (QCM-D) measurements were used alongside neutron reflectivity (NR) to evaluate any structure-function relationships contributing to the DES behaviour, aiming towards the rational design of neoteric solvents for transdermal delivery.
Wang, Xinati; Lamantia, Angelo; Jay, Michael; Sadeghi, Hatef; Lambert, Colin J; Kolosov, Oleg V; Robinson, Benjamin
Determination of electric and thermoelectric properties of molecular junctions by AFM in peak force tapping mode Journal Article
In: Nanotechnology, 2023.
Abstract | Links | BibTeX | Tags: Functional Theory (DFT) Calculations, Molecular Thin Films, openQCM, openQCM Q-1, QCM, QCM-D, Self-Assembled Monolayers (SAMs)
@article{wang2023determination,
title = {Determination of electric and thermoelectric properties of molecular junctions by AFM in peak force tapping mode},
author = {Xinati Wang and Angelo Lamantia and Michael Jay and Hatef Sadeghi and Colin J Lambert and Oleg V Kolosov and Benjamin Robinson},
url = {https://iopscience.iop.org/article/10.1088/1361-6528/acdf67/meta},
doi = {https://doi.org/10.1088/1361-6528/acdf67},
year = {2023},
date = {2023-06-19},
urldate = {2023-06-19},
journal = {Nanotechnology},
abstract = {Molecular thin films, such as self-assembled monolayers (SAMs), offer the possibility of translating the optimised thermophysical and electrical properties of high-Seebeck-coefficient single molecules to scalable device architectures. However, for many scanning probe-based approaches attempting to characterise such SAMs, there remains a significant challenge in recovering single-molecule equivalent values from large-area films due to the intrinsic uncertainty of the probe-sample contact area coupled with film damage caused by contact forces. Here we report a new reproducible non-destructive method for probing the electrical and thermoelectric properties of small assemblies (10 – 103) of thiol-terminated molecules arranged within a SAM on a gold surface, and demonstrate the successful and reproducible measurements of the equivalent single-molecule electrical conductivity and Seebeck values. We have used a modified thermal-electric force microscopy (TEFM) approach, which integrates the conductive-probe atomic force microscope, a sample positioned on a temperature-controlled heater, and a probe-sample peak-force feedback that interactively limits the normal force across the molecular junctions. The experimental results are interpreted by density functional theory calculations allowing quantification the electrical quantum transport properties of both single molecules and small clusters of molecules. Significantly, this approach effectively eliminates lateral forces between probe and sample, minimising disruption to the SAM while enabling simultaneous mapping of the SAMs nanomechanical properties, as well as electrical and/or thermoelectric response, thereby allowing correlation of the film properties.},
keywords = {Functional Theory (DFT) Calculations, Molecular Thin Films, openQCM, openQCM Q-1, QCM, QCM-D, Self-Assembled Monolayers (SAMs)},
pubstate = {published},
tppubtype = {article}
}
Molecular thin films, such as self-assembled monolayers (SAMs), offer the possibility of translating the optimised thermophysical and electrical properties of high-Seebeck-coefficient single molecules to scalable device architectures. However, for many scanning probe-based approaches attempting to characterise such SAMs, there remains a significant challenge in recovering single-molecule equivalent values from large-area films due to the intrinsic uncertainty of the probe-sample contact area coupled with film damage caused by contact forces. Here we report a new reproducible non-destructive method for probing the electrical and thermoelectric properties of small assemblies (10 – 103) of thiol-terminated molecules arranged within a SAM on a gold surface, and demonstrate the successful and reproducible measurements of the equivalent single-molecule electrical conductivity and Seebeck values. We have used a modified thermal-electric force microscopy (TEFM) approach, which integrates the conductive-probe atomic force microscope, a sample positioned on a temperature-controlled heater, and a probe-sample peak-force feedback that interactively limits the normal force across the molecular junctions. The experimental results are interpreted by density functional theory calculations allowing quantification the electrical quantum transport properties of both single molecules and small clusters of molecules. Significantly, this approach effectively eliminates lateral forces between probe and sample, minimising disruption to the SAM while enabling simultaneous mapping of the SAMs nanomechanical properties, as well as electrical and/or thermoelectric response, thereby allowing correlation of the film properties.
Lino, Catarina; Barrias, Sara; Chaves, Raquel; Adega, Filomena; Fernandes, José Ramiro; Martins-Lopes, Paula
Development of a QCM-based biosensor for the detection of non-small cell lung cancer biomarkers in liquid biopsies Journal Article
In: Talanta, pp. 124624, 2023.
Abstract | Links | BibTeX | Tags: biosensors, blood plasma, Cancer, DNA, openQCM Q-1, QCM, Quartz Crystal Microbalance
@article{lino2023development,
title = {Development of a QCM-based biosensor for the detection of non-small cell lung cancer biomarkers in liquid biopsies},
author = {Catarina Lino and Sara Barrias and Raquel Chaves and Filomena Adega and José Ramiro Fernandes and Paula Martins-Lopes},
url = {https://www.sciencedirect.com/science/article/pii/S0039914023003752},
doi = {https://doi.org/10.1016/j.talanta.2023.124624},
year = {2023},
date = {2023-05-04},
urldate = {2023-05-04},
journal = {Talanta},
pages = {124624},
publisher = {Elsevier},
abstract = {Lung cancer is the main malignant cancer reported worldwide, with one of the lowest survival rates. Deletions in the Epidermal Growth Factor Receptor (EGFR) gene are often associated with non-small cell lung cancer (NSCLC), a common subtype of lung cancer. The detection of such mutations provides key information for the diagnosis and treatment of the disease; therefore, the early screening of such biomarkers is of vital importance. The need for fast, reliable, and early detection means applied to NSCLC has led to the development of highly sensitive devices that can detect cancer-associated mutations. Such devices, known as biosensors, are a promising alternative to more conventional detection methods and can potentially alter the way cancer is diagnosed and treated. In this study, we report the development of a DNA-based biosensor, namely a quartz crystal microbalance (QCM), applied to the detection of NSCLC, from liquid biopsies samples. The detection, as is the case of most DNA biosensors, is based on the hybridization between the NSCLC-specific probe and the sample DNA (containing specific mutations associated with NSCLC). The surface functionalization was performed with a blocking agent (dithiothreitol) and thiolated-ssDNA strands. The biosensor was able to detect specific DNA sequences in both synthetic and real samples. Aspects such as reutilization and regeneration of the QCM electrode were also studied.},
key = {QCM, Quartz Crystal Microbalance, openQCM Q-1, DNA, cancer, biosensor, blood plasma},
keywords = {biosensors, blood plasma, Cancer, DNA, openQCM Q-1, QCM, Quartz Crystal Microbalance},
pubstate = {published},
tppubtype = {article}
}
Lung cancer is the main malignant cancer reported worldwide, with one of the lowest survival rates. Deletions in the Epidermal Growth Factor Receptor (EGFR) gene are often associated with non-small cell lung cancer (NSCLC), a common subtype of lung cancer. The detection of such mutations provides key information for the diagnosis and treatment of the disease; therefore, the early screening of such biomarkers is of vital importance. The need for fast, reliable, and early detection means applied to NSCLC has led to the development of highly sensitive devices that can detect cancer-associated mutations. Such devices, known as biosensors, are a promising alternative to more conventional detection methods and can potentially alter the way cancer is diagnosed and treated. In this study, we report the development of a DNA-based biosensor, namely a quartz crystal microbalance (QCM), applied to the detection of NSCLC, from liquid biopsies samples. The detection, as is the case of most DNA biosensors, is based on the hybridization between the NSCLC-specific probe and the sample DNA (containing specific mutations associated with NSCLC). The surface functionalization was performed with a blocking agent (dithiothreitol) and thiolated-ssDNA strands. The biosensor was able to detect specific DNA sequences in both synthetic and real samples. Aspects such as reutilization and regeneration of the QCM electrode were also studied.
Lim, Hui Jean; Saha, Tridib; Tey, Beng Ti; Lal, Sunil Kumar; Ooi, Chien Wei
In: Surfaces and Interfaces, pp. 102904, 2023.
Abstract | Links | BibTeX | Tags: molecularly imprinting, openQCM Q-1, polydopamine, proteins, QCM, Quartz Crystal Microbalance, sensing films
@article{lim2023quartz,
title = {Quartz crystal microbalance-based biosensing of proteins using molecularly imprinted polydopamine sensing films: Interplay between protein characteristics and molecular imprinting effect},
author = {Hui Jean Lim and Tridib Saha and Beng Ti Tey and Sunil Kumar Lal and Chien Wei Ooi},
url = {https://www.sciencedirect.com/science/article/abs/pii/S2468023023002742},
doi = {https://doi.org/10.1016/j.surfin.2023.102904},
year = {2023},
date = {2023-04-29},
urldate = {2023-04-29},
journal = {Surfaces and Interfaces},
pages = {102904},
publisher = {Elsevier},
abstract = {Biomimetic sensing films based on molecularly imprinted polydopamine (MIPDA) offer a simple, biocompatible, and versatile approach to functionalise quartz crystal microbalance (QCM)-based biosensors for the recognition of target proteins. This study aims to investigate the chemical, morphological, and recognition properties of MIPDA sensing films polymerised on the QCM crystal surface and elucidate the impacts of various parameters on the liquid-phase biosensing behaviour. Pepsin, bovine serum albumin, human serum albumin, and lysozyme were used as model proteins to study the effect of molecular imprinting and the influence of protein characteristics on the recognition behaviour of MIPDA-functionalised QCM crystals. Analysis of the protein adsorption patterns revealed that the MIPDA film contained heterogeneous binding sites with a dissociation constant in the µM range, showing that the binding affinity of the synthetic sensing film for the target protein was comparable to that of commonly used bioreceptors. In a case study using a pepsin-imprinted MIPDA film, the specific conformation and surface chemistry of the recognition cavities were discovered to promote the binding of pepsin (imprinting factor = 5.78) while simultaneously reducing the nonspecific binding of incompatible proteins on the QCM crystal surface. Protein recognition on MIPDA-functionalised QCM crystals was found to be governed by a combination of nonspecific interactions (e.g., electrostatic and polar interactions) between the proteins and the MIPDA sensing film. The findings indicate that increasing the density of selective recognition cavities in the MIPDA film and optimising the sample pH are key strategies to improve the selectivity and sensitivity for protein biosensing.},
keywords = {molecularly imprinting, openQCM Q-1, polydopamine, proteins, QCM, Quartz Crystal Microbalance, sensing films},
pubstate = {published},
tppubtype = {article}
}
Biomimetic sensing films based on molecularly imprinted polydopamine (MIPDA) offer a simple, biocompatible, and versatile approach to functionalise quartz crystal microbalance (QCM)-based biosensors for the recognition of target proteins. This study aims to investigate the chemical, morphological, and recognition properties of MIPDA sensing films polymerised on the QCM crystal surface and elucidate the impacts of various parameters on the liquid-phase biosensing behaviour. Pepsin, bovine serum albumin, human serum albumin, and lysozyme were used as model proteins to study the effect of molecular imprinting and the influence of protein characteristics on the recognition behaviour of MIPDA-functionalised QCM crystals. Analysis of the protein adsorption patterns revealed that the MIPDA film contained heterogeneous binding sites with a dissociation constant in the µM range, showing that the binding affinity of the synthetic sensing film for the target protein was comparable to that of commonly used bioreceptors. In a case study using a pepsin-imprinted MIPDA film, the specific conformation and surface chemistry of the recognition cavities were discovered to promote the binding of pepsin (imprinting factor = 5.78) while simultaneously reducing the nonspecific binding of incompatible proteins on the QCM crystal surface. Protein recognition on MIPDA-functionalised QCM crystals was found to be governed by a combination of nonspecific interactions (e.g., electrostatic and polar interactions) between the proteins and the MIPDA sensing film. The findings indicate that increasing the density of selective recognition cavities in the MIPDA film and optimising the sample pH are key strategies to improve the selectivity and sensitivity for protein biosensing.
2022
Matsumoto, Atsushi; Yoshizawa, Ryota; Funari, Riccardo; Urakawa, Osamu; Inoue, Tadashi; Shen, Amy Q
Rheology of the Electric Double Layer In Ionic Liquid Solutions: Effects of Ion Concentration and Anion Structures Journal Article
In: Available at SSRN 4096144, 2022.
Abstract | Links | BibTeX | Tags: Electric Double Layer, Electrostatic Screening, Ionic Liquid, openQCM Q-1, Quartz Crystal Microbalance, Rheology, Viscoelastic Properties
@article{matsumoto4096144rheology,
title = {Rheology of the Electric Double Layer In Ionic Liquid Solutions: Effects of Ion Concentration and Anion Structures},
author = {Atsushi Matsumoto and Ryota Yoshizawa and Riccardo Funari and Osamu Urakawa and Tadashi Inoue and Amy Q Shen},
url = {https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4096144},
doi = {https://dx.doi.org/10.2139/ssrn.4096144},
year = {2022},
date = {2022-04-28},
urldate = {2022-04-28},
journal = {Available at SSRN 4096144},
abstract = {Ionic liquids (IL) are molten salts with melting temperatures below 100°C. Combined with other unique properties such as high thermal and electrochemical stability, non-volatility and high ionic conductivity, they have been used as electrolytes in batteries and lubricants, where the viscoelasticity of the electric double layer (EDL) plays an important role. Due to the small length scale of EDL thickness, it has been challenging to characterize their viscoelastic properties at nanoscale. Herein, by using a quartz crystal microbalance (QCM), we measure the changes in the resonant frequency and energy dissipation of a gold-coated quartz crystal on which IL solutions are deposited. Since the gold surface of the quartz crystal is negatively charged at an open circuit potential, we can estimate the loss modulus of the EDL near the charged surface through a wave propagation model. Using this approach, we investigate the viscoelastic properties of the EDL formed on the quartz crystal from three ionic liquids with different anions: 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (Bmim-TFSI); 1-butyl-3-methylimidazolium trifluoromethanesulfonate (Bmim-TfO); 1-butyl-3-methylimidazolium tetrafluoroborate (Bmim-BF4). We find that the loss modulus of the EDL increases rapidly with increasing ionic liquid concentrations in the low concentration regime, but reaches about 3 orders of magnitude larger than the loss modulus of the bulk solution in the higher concentration regime. This behavior is independent of the type of anions. Our results can provide useful information on the rheological properties of the EDL in IL solutions, optimizing IL-based material design with improved system performances.},
keywords = {Electric Double Layer, Electrostatic Screening, Ionic Liquid, openQCM Q-1, Quartz Crystal Microbalance, Rheology, Viscoelastic Properties},
pubstate = {published},
tppubtype = {article}
}
Ionic liquids (IL) are molten salts with melting temperatures below 100°C. Combined with other unique properties such as high thermal and electrochemical stability, non-volatility and high ionic conductivity, they have been used as electrolytes in batteries and lubricants, where the viscoelasticity of the electric double layer (EDL) plays an important role. Due to the small length scale of EDL thickness, it has been challenging to characterize their viscoelastic properties at nanoscale. Herein, by using a quartz crystal microbalance (QCM), we measure the changes in the resonant frequency and energy dissipation of a gold-coated quartz crystal on which IL solutions are deposited. Since the gold surface of the quartz crystal is negatively charged at an open circuit potential, we can estimate the loss modulus of the EDL near the charged surface through a wave propagation model. Using this approach, we investigate the viscoelastic properties of the EDL formed on the quartz crystal from three ionic liquids with different anions: 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (Bmim-TFSI); 1-butyl-3-methylimidazolium trifluoromethanesulfonate (Bmim-TfO); 1-butyl-3-methylimidazolium tetrafluoroborate (Bmim-BF4). We find that the loss modulus of the EDL increases rapidly with increasing ionic liquid concentrations in the low concentration regime, but reaches about 3 orders of magnitude larger than the loss modulus of the bulk solution in the higher concentration regime. This behavior is independent of the type of anions. Our results can provide useful information on the rheological properties of the EDL in IL solutions, optimizing IL-based material design with improved system performances.
