Dopamine-Mediated Attenuation of OECT-Based Aqueous Artificial Chemical Synapses

Artificial synaptic electronic devices capable of chemical communication effectively emulate the functions and behaviors of biological synapses, making them indispensable for constructing neuromorphic computing systems and biomedical interfaces. Although many artificial synapses modulated by neurotransmitters and biomolecules have been developed, the attenuation of inhibitory and excitatory synaptic responses induced by these chemicals, which is indispensable for regulating biological nervous systems, has rarely been reported. Herein, we report an artificial synapse based on a floating-gate organic electrochemical transistor (OECT) in which dopamine attenuates various synaptic behaviors in an aqueous environment. By utilizing a floating-gate structure and an ionic gel as the primary electrolyte, our device exhibits characteristic inhibitory and excitatory synaptic behaviors. When dopamine is added to the secondary aqueous electrolyte, its dopaminergic oxidation further dedopes the floating gate, leading to the observed reduction in synaptic modulation. This study provides a practical approach to achieving chemically modulated synaptic behavior, contributing to the design of biointerfaced neuromorphic components.