Recent advances in Electrochemical Detection of Exocytosis

Taking advantages of the analytical properties of ultramicroelectrodes, amperometry at constant potential has been a common technique for investigating exocytosis at the cell level for two decades. The historical experimental configuration, named “artificial synapse”, mainly involves a micrometric carbon fiber electrode in the close vicinity of the investigated cell whose exocytotic release thus appears as a succession of amperometric spikes, whose frequency and shapes are particularly informative about the dynamics of the release process, while their areas (charge) directly correspond to the amount of molecules released. While the “single” carbon fiber still contributes to the understanding of the exocytotic mechanism, microsystems and microdevices have blossomed during the recent years and aim to gradually replace the historical experimental configuration by notably allowing coupling with spectroscopies and microscopies (optical, fluorescent). Such changes over the five last years are described and discussed in this review.