For over 60 years, drugs that alter, mimic, or block modulatory neurotransmitters have formed the core arsenal for the treatment of neurological disorders such as depression, addiction, schizophrenia, anxiety, and Parkinson’s disease. Nonetheless, methods to measure neurotransmitters remain sparse, particularly to detect the three modulatory neurotransmitters that govern brain function: dopamine, serotonin, and norepinephrine. We describe the design, characterization, and implementation of near-infrared optical sensors to image neurotransmitter dopamine. Dopamine is a key molecular governor of brain function, whereby dopamine imbalances lead to neurodegenerative and behavioral disorders. We show direct visualization of endogenous dopamine release over multiple rounds of acute brain slice stimulation, for over 80 minutes. We characterize this sensor in the context of its utility for high spatial and temporal neurotransmitter imaging in the brain, describe it function from a molecular dynamics (MD) perspective, validate its use in vitro, and extrapolate its use in vivo to correlate external stimuli (experiences, behavior) to chemical output (neurotransmission).