Cell adhesion is an essential aspect of cellular behavior. Finding innovative methods to probe the adhesion of cells in their native state can greatly advance the understanding of control and ...regulation of cellular behavior and their impact on human health. The quartz crystal microbalance (QCM) is a label-free, biosensing system that has, in the past fifty years, evolved from a simple acoustic based mass sensor to a powerful bioanalytical tool. Its unique capability of monitoring the cell-substrate interaction non-invasively in real time has led to the emergence of its applications in areas that are relevant to fundamental cell biology and medical research. This review is intended to provide readers an overview of the use of the QCM for examination of cell-substrate adhesion. It also describes how this innovative approach can be extended to the study of other aspects of cellular behavior, such as cell morphology, cell mechanics, cell motility, cell signaling, all of which can potentially be applied to medical diagnosis and/or pharmaceutical development. In this review a major emphasis is placed on informing readers about some of the most important practical aspects of the QCM-based cell study including data acquisition and analysis, the substrate surface manipulation, and cell manipulation.
•Overview of the use of the QCM for examination of cell-substrate adhesion.•Discussion on how the QCM-based approach can be extended to the study of other aspects of cellular behavior.•Review of some of the most important practical aspects of the QCM-based cell study.
A quartz crystal microbalance (QCM) is an instrument that has the ability to measure nanogram‐level changes in mass on a quartz sensor and is traditionally used to probe surface interactions and ...assembly kinetics of synthetic systems. The addition of dissipation monitoring (QCM‐D) facilitates the study of viscoelastic systems, such as those relevant to molecular and cellular mechanics. Due to real‐time recording of frequency and dissipation changes and single protein‐level precision, the QCM‐D is effective in interrogating the viscoelastic properties of cell surfaces and in vitro cellular components. However, few studies focus on the application of this instrument to cytoskeletal systems, whose dynamic parts create interesting emergent mechanics as ensembles that drive essential tasks, such as division and motility. Here, we review the ability of the QCM‐D to characterize key kinetic and mechanical features of the cytoskeleton through in vitro reconstitution and cellular assays and outline how QCM‐D studies can yield insightful mechanical data alone and in tandem with other biophysical characterization techniques.
Abstract
We report reversible electrochemical insertion of NO
3
−
into manganese(II, III) oxide (Mn
3
O
4
) as a cathode for aqueous dual‐ion batteries. Characterization by TGA, FTIR, EDX, XANES, ...EXAFS, and EQCM collectively provides unequivocal evidence that reversible oxidative NO
3
−
insertion takes place inside Mn
3
O
4
. Ex situ HRTEM and corresponding EDX mapping results suggest that NO
3
−
insertion de‐crystallizes the structure of Mn
3
O
4
. Kinetic studies reveal fast migration of NO
3
−
in the Mn
3
O
4
structure. This finding may open a new direction for novel low‐cost aqueous dual‐ion batteries.
Measurement of antithyroglobulin antibodies (TgAb) is an inevitable laboratory tool in the management of thyroid gland diseases. Currently available immunoassays still have limitations underlying the ...necessity of the introduction of fast, sensitive, and label-free technologies. Our aim was to develop a method for TgAb measurement in human serum based on the quartz crystal microbalance (QCM) technology. We immobilized thyroglobulin on the surface of Attana LNB Carboxyl sensor chip®, prepared standard curve covering the range of 1–50000 kIU/L, and established optimal measurement conditions. The validation included determination of the detection limit (LOD), functional sensitivity, linearity, precision, as well as the comparison with the results of the radioimmunoassay (RIA). The LOD and functional sensitivity were 4.2 kIU/L and 4.7 kIU/L, respectively. The method was linear in the range of 20–10000 kIU/L. The regression equation for comparison with RIA was CQCM= 1.0056 • CRIA– 24.2778, whereby no significant proportional or systematic difference was present. There was a good agreement with RIA in the classification of patients according to the clinical significance of the results. The developed method has advantages over currently available assays in terms of better LOQ, a higher upper limit of linearity, and precision.
The characteristics of the developed method unambiguously show that the application of the QCM biosensors offers a highly reliable novel approach for the measurement of TgAb in human serum.
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•A novel QCM biosensor method for TgAb measurement is established.•Measurement results are in good correlation with the standard RIA method.•The assay shows low LOD, extended upper limit of linearity and high precision.•The method is applicable for human sera analysis.
Infectious diseases are the ever-present threats to public health and the global economy. Accurate and timely diagnosis is crucial to impede the progression of a disease and break the chain of ...transmission. Conventional diagnostic techniques are typically time-consuming and costly, making them inefficient for early diagnosis of infections and inconvenient for use at the point of care. Developments of sensitive, rapid, and affordable diagnostic methods are necessary to improve the clinical management of infectious diseases. Quartz crystal microbalance (QCM) systems have emerged as a robust biosensing platform due to their label-free mechanism, which allows the detection and quantification of a wide range of biomolecules. The high sensitivity and short detection time offered by QCM-based biosensors are attractive for the early detection of infections and the routine monitoring of disease progression. Herein, the strategies employed in QCM-based biosensors for the detection of infectious diseases are extensively reviewed, with a focus on prevalent diseases for which improved diagnostic techniques are in high demand. The challenges to the clinical application of QCM-based biosensors are highlighted, along with an outline of the future scope of research in QCM-based diagnostics.
•QCM-based biosensors are promising tools for the rapid detection of infections.•Discussion of strategies for detecting disease biomarkers in QCM platforms.•Review of reported QCM-based biosensors for prevalent infectious diseases.•Overview of research opportunities in QCM-based diagnostics.•Microfluidic systems can boost the applicability of QCM for point-of-care diagnosis.
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Phospholipids and hyaluronan have been implied to fulfil important roles in synovial joint lubrication. Since both components are present in synovial fluid, self-assembly structures ...formed by them should also be present. We demonstrate by small angle X-ray scattering that hyaluronan associates with the outer shell of dipalmitoylphophatidylcholine (DPPC) vesicles in bulk solution. Further, we follow adsorption to silica from mixed hyaluronan/DPPC vesicle solution by Quartz Crystal Microbalance with Dissipation measurements. Atomic Force Microscope imaging visualises the adsorbed layer structure consisting of non-homogeneous phospholipid bilayer with hyaluronan/DPPC aggregates on top. The presence of these aggregates generates a long-range repulsive surface force as two such surfaces are brought together. However, the aggregates are easily deformed, partly rearranged into multilayer structures and partly removed from between the surfaces under high loads. These layers offer very low friction coefficient (<0.01), high load bearing capacity (≈23MPa), and self-healing ability. Surface bound DPPC/hyaluronan aggregates provide a means for accumulation of lubricating DPPC molecules on sliding surfaces.
Ehrlichia canis is an intracellular parasitic bacterium and arthropod-borne pathogen that receives growing attention, because it leads to increasing morbidity and mortality in animals. It does so by ...causing canine monocytotropic ehrlichiosis (CME). Infected canines may lack obvious clinical signs and stay in chronic stage. Herein we report a rapid screening method based on PCR assay combined with quartz crystal microbalance (QCM) to design a DNA sensor for detecting E. canis in early stages of infection. The test relies on DNA amplification of target nucleotide sequences via PCR followed by detecting DNA-DNA hybridization using QCM. The approach did not result in any cross-hybridization toward other blood bacteria or parasites in dogs, such as Anaplasma platys, Babesia canis and Trypanosoma spp, but turned out selective for the target species. The limit of detection of QCM was as low as 4.1 × 109 molecules/μl of 289 bp E. canis PCR products corresponding to 22 copy numbers/μl of E. canis. Furthermore, the technique is also simple, does not require complicated equipment and can in principle be reused.
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•A rapid screening method based on PCR assay combined with quartz crystal microbalance (QCM) for detecting E. canis.•Detection via DNA-DNA hybridization using QCM in situ.•The technique is simple, does not require complicated equipment and can be reused.•Immobilizing specific capture probes on the surfaces of QCM is suitable for rapidly detecting DNA of E. canis.•QCM-based DNA sensors turned out sensitive and highly selective against other canine blood parasites or pathogens.
AT-cut quartz crystals vibrating in the thickness-shear mode (TSM), especially quartz crystal resonators (QCRs), are well known as very efficient mass sensitive systems because of their sensitivity, ...accuracy, and biofunctionalization capacity. They are highly reliable in the measurement of the mass of deposited samples, in both gas and liquid matrices. Moreover, they offer real-time monitoring, as well as relatively low production and operation costs. These features make mass sensitive systems applicable in a wide range of different applications, including studies on protein and peptide primary packaging, formulation, and drug product manufacturing process development. This review summarizes the information on some particular implementations of quartz crystal microbalance (QCM) instruments in protein and peptide drug product development as well as their future prospects.
With the in-depth application of quartz crystal microbalance (QCM) sensors in the fields of science and engineering, there is an urgent need for QCM sensors with high mass sensitivity. The mass ...sensitivity of a QCM is closely related to its resonance frequency, and the high resonance frequency leads to improve its mass sensitivity. However, the resonance frequency of a QCM resonator cannot be increased all the time due to the fragility of quartz wafer and the limits of energy trapping effect. Few studies are associated with mass sensitivity of a QCM resonator under overtone modes. Herein, we propose to make a QCM resonator work in its n-th overtone (n = 3, 5, 7, 9 in this study) mode to increase its resonance frequency during operating. Thereby, the purpose of improving QCM mass sensitivity is achieved, and the mass sensitivity of a QCM working in the n-th overtone mode can be called as n-th overtone mass sensitivity. Then, the n-th overtone mass sensitivity of a QCM sensor is measured by an electrodeposition method. The experimental results show that the n-th overtone mass sensitivity of a QCM is a bit more than n times that of the fundamental mass sensitivity, and it is consistent with the theoretical calculation results. The application of overtone mass sensitivity will greatly improve the sensitivity of QCM sensors, which is very attractive for the research fields that require QCM sensors with high sensitivity.
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