Electronic sensors with living cellular components

For more than three decades, it has been possible to use microlithographically fabricated extracellular electrodes to record action potential (AP) signals from electrically active cells such as neurons of intact organisms. There has also been a steady evolution of techniques to interface between electronic circuits and neural or cardiac cells cultured on arrays of such electrodes, mainly directed toward basic science goals. More recently, such combinations of living cells and electronics have been harnessed as tools for the detection of chemical and biological toxins, and for screening of pharmacologically active compounds. This paper presents a survey of the relevant technologies, cell types available, specific requirements for applications, and discussion of opportunities for future development.