A Highly Sensitive 27 MHz Quartz-Crystal Microbalance as a Device for Kinetic Measurements of Molecular Recognition on DNA Strands

Abstract

DNA-DNA hybridization and DNA-protein or enzyme interactions are essential steps in biomolecular recognitions. These interactions have been conventionally studied by gel mobility shift assay. This technique gives us only qualitative information, we must label enzymes radioactive or fluorescent molecules, and it takes a relatively long time to analyze the results. Here we introduce a new tool of a highly sensitive 27 MHz quartz-crystal microbalance (QCM), in which the resonance frequency decreases linearly with the increase of mass on the electrode area at the nanogram level. Thus, when a host molecule is immobilized on a QCM, the binding behavior and its kinetics can be monitored from frequency changes due to the guest binding in aqueous solution. The results are also compared with those from a surface plasmon resonance sensor.

Atomic Force Microscopy and Quartz Crystal Microbalance Study of the Lectin-Carbohydrate Interaction Kinetics

“…First, the measurements of the frequency response as a function of time using seven different concentrations of added ligands (0.1, 0.3, 0.6, 1.0, 2.0, 2.5, 5.0 µM CaY) were carried out. The following relation was applied to process the obtained data [7][8][9]:…”

“…AFM in its force spectroscopy mode allows the determination of the dissociation rate constant and the position of the transition state of the energy barrier characterizing the dissociation process of the studied molecular complex [5,6]. QCM also enables the estimation of the dissociation rate constant as well as the equilibrium and association rate constants of molecular interactions [7][8][9]. Such AFM or QCM experiments are carried out in liquid, using immobilized receptor molecules, whereas the used ligands may be either free in solution (for QCM measurements) or immobilized on the probe tip (for AFM measurements).…”

Piezo Electric Sensor for Endocrine-Disrupting Chemicals Using Receptor–co-factor Interaction

“…10 min due to the adsorption of the complex on the NTA-modified surface. According to Sauerbrey's equation, 15 the adsorption amount under the equilibrium condition was calculated to be 244 ng from the frequency decrease after protein binding. Assuming that hER-LBD and hsp90 form the 1:1 complex in molar ratio, 2 pmol of the complex should be immobilized on the gold surface of the QCM.…”

Construction of simultaneous SPR and QCM sensing platform

“…Thus, the problem of signal noise can be solved if a lower viscous index matching oil is used in the future. Plus, further development is required applying a high frequency [14,15] or overtone [16][17][18] modes of the QCM to enhance the sensitivity. Various applications, which are normally treated as a possible area of QCM application, may be possible in biosensor with these developments [13].…”

“…A quartz crystal microbalance (QCM) is also well known as a sensitive mass detecting device and thin film microrheology monitoring device, and its theory and applications have also been well documented in previous reviews [13]. In the case of a 9 MHz quartz crystal, the mass sensitivity is normally of a nano gram order, but applying a high frequency mode [14,15] and an overtone mode [16][17][18] produces better sensitivity within a sub-nano gram order.…”