Bioinspired Nanofluidic Synapse Capable of Dopamine Sensing with an Inverted-U Dose–Response Function

In biology, synaptic sensing of neurotransmitter dopamine (DA) has proven to exhibit a characteristic inverted-U shaped dose-response function on cognitive performance and working memory in the prefrontal cortex. With this inspiration, we present a nanofluidic synapse capable of simulating such an intricate behavior by a rationally designed DNA-based DA-responsive nanosensor with good selectivity, reversibility, and stability. The presence of DA could cause gradual DNA collapse and thus regulation of ion flux passing through the nanofluidic synapse, leading to unique DA-mediated hysteresis and synaptic characteristics of an inverted-U manner, based on which artificial neural network-enabled image recognition is done with an inverted-U shaped efficiency and accuracy.