ABSTRACT
A biosensor is an analytical device that determines the specific interactions between biological molecules. Biosensors that convert a biological response into an electrical signal are integrated by a physicochemical transducer in various forms such as optical, electrochemical, thermometric, magnetic, or piezoelectric. This chapter gives an overview of the fundamental aspects of resonant sensors and describes some of the quartz crystal surface modification methods. It specifies the application of the quartz crystal microbalance (QCM) technique to various measurements involving enzymes, proteins, nucleic acids, and cell biosensors in the fields of drug discovery and biomaterials research. The QCM technique was initially introduced to monitor the adsorption of mass on a quartz surface from chemical species in the gas phase. More recently, after the integration of the quartz crystal into liquid conditions, the solution-based QCM became a medium in bioanalytical applications to measure adsorption at solution– surface interfaces.
