Potassium concentration alters calibration sensitivities of dopamine but not serotonin

The use of carbon fibre microelectrodes and amperometric techniques for measurement of biological molecules has been widely studied. The use of calibrations to translate biological data is common practice between labs. Tris buffer is commonly used for conducting calibrations, where potassium ion concentrations are varied in buffers. However, little is known about how changes in this ion alter the calibration sensitivity of neurotransmitters. This work showcases that dopamine calibrations are highly dependent on the concentration of potassium ions, whilst serotonin is less affected. Our findings have implications on interpretation and comparison of measurements between different studies.