A Review of Interface Electronic Systems for AT-cut Quartz Crystal Microbalance Applications in Liquids

Abstract

From the first applications of AT-cut quartz crystals as sensors in solutions more than 20 years ago, the so-called quartz crystal microbalance (QCM) sensor is becoming into a good alternative analytical method in a great deal of applications such as biosensors, analysis of biomolecular interactions, study of bacterial adhesion at specific interfaces, pathogen and microorganism detection, study of polymer film-biomolecule or cell-substrate interactions, immunosensors and an extensive use in fluids and polymer characterization and electrochemical applications among others. The appropriate evaluation of this analytical method requires recognizing the different steps involved and to be conscious of their importance and limitations. The first step involved in a QCM system is the accurate and appropriate characterization of the sensor in relation to the specific application. The use of the piezoelectric sensor in contact with solutions strongly affects its behavior and appropriate electronic interfaces must be used for an adequate sensor characterization. Systems based on different principles and techniques have been implemented during the last 25 years. The interface selection for the specific application is important and its limitations must be known to be conscious of its suitability, and for avoiding the possible error propagation in the interpretation of results. This article presents a comprehensive overview of the different techniques used for AT-cut quartz crystal microbalance in in-solution applications, which are based on the following principles: network or impedance analyzers, decay methods, oscillators and lock-in techniques. The electronic interfaces based on oscillators and phase-locked techniques are treated in detail, with the description of different configurations, since these techniques are the most used in applications for detection of analytes in solutions, and in those where a fast sensor response is necessary.

Surface Stiffness—a Parameter for Sensing the Chirality of Saccharides

“…29,30 Hence, we used QCM-D to monitor the dynamic adsorption processes of seven pairs of monosaccharide enantiomers…”

Gravimetric Viral Diagnostics: QCM Based Biosensors for Early Detection of Viruses

“…A number of academic research articles and review papers have been published previously that emphasize the QCM's working principle and study their performance in a wide range of complex biochemical processes taking place at the receptor-analyte interface [44][45][46][47]. These investigations highlight the surface chemistry and mechanistic events during the attachment or binding of various target analytes.…”

Highly Sensitive Dual Quartz Reactance-to-Frequency Transducer

“…Moreover, when compared also to some other methods [8][9][10][11][12][13][14][15][16][17][18][19][20] for the conversion of reactance to frequency, the newly proposed method also proved to have many advantages which include: compensation of quartz self-temperature characteristic, temperature compensation of all elements because of specific oscillator's circuit, compensated influence of the supply voltage on the oscillating circuit output signal, possibility to use of quartz crystals with different cutting angles [21,22], high circuit sensitivity and resolution. Another important factor of great importance is high dynamic stability during temperature changes in the extended operating range.…”