quartz crystal microbalance abbr., QCM; QCN otherwise quartz crystal nanobalance (rus. микровесы, кварцевые otherwise метод пьезоэлектрического микровзвешивания) — a mass measuring instrument that measures a change in frequency of a quartz crystal resonator (microbalance sensor) depending on the quantity of a substance placed on the microbalance.

Description

The key element of a quartz crystal microbalance (QCM) is a quartz crystal cut out of a monocrystal at a certain angle. Golden electrodes are connected to the quartz crystal on the top and the bottom. Applying alternating current to the crystal will induce oscillations in the crystal plate as a result of inverse piezoeffect. The vibrating system becomes resonant at a certain frequency of alternating current. When a substance is deposited on the surface of the instrument, the resonance frequency of the quartz crystal changes, allowing the mass of the deposited substance to be measured.

Quartz crystal microbalance devices are widely used in biochemical activities because they can be used in liquid environments, as well as in gas phase and under vacuum. For example, one of the biosensor types may be obtained through immobilisation on the microbalance surface of sensing biomolecules that capture a specific measured substance from a solution. Microbalance devices are most commonly applied in immunobiosensors used to recognize antibodies and DNA biosensors used to recognize short fragments of DNA or RNA molecules.

Authors

  • Ilya V. Goldt
  • Evgeny A. Goodilin