High-Resolution Amperometric Spikes From Chromaffin Cells Revealed By Boron-Doped Nanocrystalline Diamond Microelectrode Arrays

Exocytosis is a Ca2+-dependent process at the basis of synaptic transmission occurring through quantal release of neurotransmitter molecules into the synaptic cleft. Single secretory events of oxidizable molecules can be conventionally detected by means of carbon fiber microelectrodes (CFEs), with submillisecond time resolution but limited to single cells. Here we radically changed the approach of recording by adopting a planar microelectrode configuration, with the aim of detecting secretory events from different chromaffin cells simultaneously. We describe the construction of a planar nanocrystalline diamond microelectrode array for recording quantal secretory events of oxidizable neurotransmitters from living cells.