China
Africa
Explore chapters and articles related to this topic
Developing a Dynamics Model for Epidermal Growth Factor (EGF)-Induced Cellular Signaling Events
Published in Ning Xi, Mingjun Zhang, Guangyong Li, Modeling and Control for Micro/Nano Devices and Systems, 2017
Ning Xi, Ruiguo Yang, Bo Song, King Wai Chiu Lai, Hongzhi Chen, Jennifer Y. Chen, Lynn S. Penn, Jun Xi
The quartz crystal microbalance with dissipation (QCM-D) is another nanomechanical sensor that can measure interactions at the molecular level [15]. It has been used to investigate molecular processes, such as membrane formations [16], protein adsorptions [17], and cell spreading [18]. It operates in thickness-shear mode by oscillating a quartz crystal disk with high frequency (normally 5 MHz) and low amplitude (less than 1 nm in the lateral direction). It collects the frequency and amplitude changes of the quartz crystal and reveals the mechanical/structural status of the sample attached to the top of the sensor disk The shift in resonance frequency indicates the mass adsorption or loss, while the change in energy dissipation alteration can be used to derive the viscoelasticity properties of the adsorbed film on the disk [19].
Overview and Future Trends of Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
What makes QCM a useful tool in biosensing? Utilizing its ability to simultaneously detect mass and viscoelastic property changes, the QCM with dissipation monitoring (QCM-D) is the supreme tool to study biological interactions. Oligonucleotide immobilization is followed with the QCM system by measuring the frequency shifts of the crystal, which was 126 ± 12 Hz under optimal condition for a mass deposition of 380 ng cm-2 in a study carried out by Duman et al. 2003 for developing a nucleic acid sensor. This frequency shift is sufficient for sensitive measurements.
Biobased Lubricant Additives
Published in Girma Biresaw, K.L. Mittal, Surfactants in Tribology, 2017
Girma Biresaw, Grigor B. Bantchev, Zengshe Liu, David L. Compton, Kervin O. Evans, Rex E. Murray, K.L. Mittal
QCM-D depends on the total adhered mass (including solvent) that oscillates with the vibrating quartz. The measured frequencies (fundamental and several overtones) will decrease as mass increases on the surface. It should be noted that the mass measured due to the frequency changes includes all material coupled to the vibrating quartz, including trapped or adsorbed solvent.
Antiproliferative drug-loaded multi-functionalized intraocular lens for reducing posterior capsular opacification
Published in Journal of Biomaterials Science, Polymer Edition, 2021
Huiying Huang, Siqing Zhu, Dong Liu, Shimin Wen, Quankui Lin
The prepared HA-Pac was then used as one of the component to build-up the polyelectrolyte multilayer coating on the material surface via LbL deposition with positively charge CHI. The multilayer build-up process was followed by quartz crystal microbalance with dissipation monitoring (QCM-D) [32]. QCM-D is a versatile and ultra-sensitive tool to quantitatively monitor changes in film thickness and adsorbed mass without the addition of external labels. And it can provide a lot of information about key makeup of soft and solvated interfaces [33]. If a thin film attaches to the crystal surface rigidly, there exists a good linear relationship between the resonance of frequency and the mass of the film [34]. As shown in Figure 2, the frequency shift increases linearly with bilayer number, indicating a gradual deposition of HA-Pac/CHI bilayer. The result not only indicates that HA-Pac/CHI multilayer is rigidly thin attached to the substrate surfaces, but also shows a typical LbL build-up process of HA-Pac/CHI multilayer growth.
In situ characterizations for EPS-involved microprocesses in biological wastewater treatment systems
Published in Critical Reviews in Environmental Science and Technology, 2019
Peng Zhang, Bo Feng, You-Peng Chen, You-Zhi Dai, Jin-Song Guo
The traditional QCM technique is based on the piezoelectric effect, i.e., when an AC voltage is applied to a quartz crystal, it continuously oscillates according to the natural frequency if the resonant frequency of the quartz is close to the voltage frequency. The Sauerbrey equation describes the quantitative relationship between the surface quality changes of the quartz crystal and the frequency change of the quartz crystal. The QCM has come into apply in the aqueous phase until the emergence of QCM-D. QCM-D can determine the changes in the mass and the structure of the macromolecule on the surface, which supplies information on the macromolecule behavior at the interface, especially on the solid-liquid interface. The quantification level on the sensing surface reaches as low as ∼ ng/cm2.
Study on differences in the enzyme hydrolysis induced from lignins from diverse types of lignocellulosic biomass
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Chunyang Zou, Jiaquan Li, Wenjuan Wu
Traditional research methods cannot continuously monitor lignin’s effects in each cellulose hydrolysis stage. Herein, we chose to use an advanced monitoring method. Quartz crystal microbalance with dissipation (QCM-D) is a nondestructive flow analysis technique that measures changes in crystal surface quality in real-time through changes in frequency and dissipation (Du et al. 2010). QCM-D has been used to observe the real-time enzymatic adsorption/desorption, binding and related kinetics on lignocellulosic substrates (Kumagai, Lee, and Endo 2013). Suchy et al. used trimethylsilyl cellulose (TMSC) as the substrate to prepare a film of amorphous cellulose that swelled uniform in water to evaluate the enzymatic degradation of amorphous cellulose. And then comsidered how endoglucanase (EG I) acts on amorphous part of the cellulose structure. QCM-D was used to monitor the residual cellulose substrate from solution (Suchy et al. 2011). The change of frequency and dissipation reflected the velocity of hydrolysis, and the influence of buffer solution added after hydrolysis for the same time on the degradation ability of enzymes with different concentrations was also shown. Josefsson et al. used QCM-D to study fungal cellulase activity on model cellulose film (Josefsson, Henriksson, and Wågberg 2008). By fluxing endoglucanase, cellobiose hydrolase, and a mixture of two enzymes, measured the whole process through the change of frequency and dissipation. The difference in swelling, adsorption, desorption, and enzymatic hydrolysis of different enzymes on cellulose film could reflect directly by the variation of viscoelasticity and thickness. This method is instrumental in showing the effect of lignin during various processes of enzymatic hydrolysis.