Design and application of piezoelectric quartz crystal-based immunoassay

This paper describes some basic test schemes of piezoelectric quartz crysta l microbalance (QCM)-based immunoassay. These include one-step direct assay , one-step indirect assay, two-step sandwiched assay, displacement assay, a nd mass-amplified assay. Applications of these designs in the fields of cli nic diagnosis, food analysis, environmental analysis, and veterinary diagno sis are reviewed. In addition, some critical issues of QCM immunoassay are also dealt with, including the evaluation of liquid phase and gas phase det ection, and the biomolecules' coating techniques, non-specific adsorption, and regeneration of used crystals.