An electrochemical detector array to study cell biology on the nanoscale

Nanobiotechnology is a field that utilizes the techniques of nano- and microfabrication to study biosystems or to use biological material and principles to build new devices. As an example we discuss the development of a nanofabricated electrochemical detector array that reveals the spatio-temporal dynamics of exocytosis in single chromaffin cells. In a quantal release event a single vesicle fuses with the plasma membrane releasing its contents through the fusion pore. The time-resolved amperometric currents measured by the individual electrodes detecting different fractions of the released molecules allow determination of the time course as well as localization of quantal events. Such a device may be applicable to study the correlation of exocytotic events with signalling events that could be simultaneously monitored by fluorescence microscopy.