Cellular electrical impedance spectroscopy: an emerging technology of microscale biosensors

Electrical impedance spectroscopy, owing to its label-free, noninvasive and easy miniaturization nature, has shown great potential in cellular biochemical sensing and cell-based diagnostics. In this article, cutting-edge technologies of electrical impedance spectroscopy are reviewed according to different sensing mechanisms, including monitoring of ion release from live cells, utilization of nonconductive cellular membranes, and detection of the spatial distribution of cells. The most successful applications where the electrical impedance sensors have been proven effective are introduced, including investigation of anticancer drug therapies, wound healing, cytotoxicity evaluation and measurement of blood rheological behavior. Furthermore, the research advances that yield enhanced sensitivities and functionalities are introduced. Finally, the commercialization challenges and the critical barriers that hinder the sustaining development of cellular electrical impedance spectroscopy are discussed.