Compact potentiostat for cellular electrochemical imaging with 54 parallel channels

A novel potentiostat containing 54 current amplifiers matched to an array of custom-fabricated 5μm microelectrodes for electrochemical imaging of released neurotransmitters is presented. The board is integrated with a programmable microfluidic cell culture system and the whole assembly is thin and compact enough to be placed under the objective of a standard microscope for simultaneous optical and electrochemical monitoring. Each channel, scanned every 54μs, features 3pA current resolution over a 5kHz bandwidth, suitable for detecting single exocytotic events. The design and electrical characterization of the system are reported together with its functionality, certified by a 54-pixel electrochemical imaging of the diffusion of a 10μl droplet of a target analyte inside the cell culture chamber.