Fast scan cyclic voltammetry (FSCV) is a well established electrochemical technique used to measure rapid extrasynaptic (i.e. outside of the synapse, 'overflow') dopamine concentration changes in the brain [Robinson & Wightman 2007]. FSCV has been shown to provide optimal performance in terms of fast (100 millisecond) sampling, microscale resolution, and chemical selectivity. Nevertheless, numerous strategies have been developed and/or are being advanced to enhance neurochemical detection [Gonon & Buda 1985], [Blaha & Phillips 1997], [Ngernsutivorakul et al 2018], [Nakatsuka et al 2018].
FSCV works by applying small voltage ramps every 100 ms to an implanted carbon fiber (CF) electrode. Electroactive molecules near the CF will oxidize or reduce at specific voltages, transferring electrons or protons to the CF that can be directly recorded in the form of current. Dopamine displays selective redox current at ~ - 0.2 & + 0.6 V. The CF has been shown to provide an optimal interface in terms of biocompatibililty and a highly adsorptive interface for sensitive dopamine detection [McCreery 2008].
open-source DIY multi-channel fscv
We developed custom-made FSCV systems to provide recording of dopamine from up to 16 channels/sites as commercially available systems only provided 4 channels of operation. Our system is a cost-affordable alternative and can easily be constructed with off-shelf electronics and a PC-data acquistion system (DAQ).
Some information to guide users on how to build this system is available on github.
I hope to update this link soon as we are working on expanding the number of channels and reducing the size of the circuits.