Fast scan cyclic voltammetry is a powerful technique for selective detection of biogenic amines in vivo and in vitro. Here we investigate this technique for multichannel spatiotemporal detection of neurotransmitter concentrations on a chip, using metal microelectrode arrays. The array-based approach allows monitoring concentration gradients of redox-active species at multiple highly localized (3 µm) positions simultaneously, while maintaining selectivity from the characteristic voltammogram shapes. We demonstrate that concentration fluctuations at individual electrode locations are resolved after spatially confined neurotransmitter injections. Furthermore, we discuss effects of microelectrode degradation caused by electrode sweeping during long-term experiments.