Quartz-crystal sensors for biosensing and chemical analysis

Abstract

The principle and applications of quartz-crystal sensors based on the three basic concepts for mass, viscosity, and viscoelastic changes are reported. In the general discussion the realization of a resonant frequency-resonant resistance diagram is described in detail. As an example of application to mass sensing, gas sensing with a carbon-coated quartz crystal is reported. Determination of the blood coagulation factor is used as an example of the application to viscosity sensing. As an example of viscoelastic measurement, an ion-exchange polymer-coated quartz crystal is investigated to show that viscoelasticity changes more than mass in the transport process. The possibility of developing new biosensors and chemical sensors is discussed on the basis of these results.

Construction of simultaneous SPR and QCM sensing platform

“…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]. Finally, the data is reproducible within the standard deviation range of 5% in our 5 experiments continuously with a similar response shape.…”

“…7 and 8), respectively. These changes are within the normal range that occurs when a QCM comes into contact with water [13]. However, the deviations in the resonant frequency and resonant resistance were only about 50 Hz and 2 X after reaching a stable area (time after 1 h), respectively, which are not enough to detect a small mass change and only effective for detecting a large mass change, such as living cells under certain conditions [6,7].…”

“…A selective sensor is then obtained when the sensor surface is coated with a selectively interacting thin film, which was introduced by King in 1964 based on a piezoelectric sorption detector. 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.…”

Current research activity in biosensors

“…QCM biosensors have also been developed widely, and their theory and applications have been described in a review article [158] and in a research article that reported the three basic concepts of QCM -mass, viscosity, and viscoelastic changes [159]. As a new fundamental study an immunosensor was developed by a novel method of immobilizing antibodies on a QCM using ethylenediamine PPF [99].…”

Modelling of blood component flexibility using quartz crystal microbalance

“…QCM exhibits a high sensitivity for monitoring dynamic processes in blood, including cell sedimentation and aggregation, coagulation, plasma protein absorption, as well as evaluating the bio-compatibility/ affinity of different materials, etc. [1,2,3,4]. In order to use QCM sensor in diagnostics, measured sensor resonant characteristics are typically converted to interpretable physical parameters characterizing blood and/or blood components.…”