Bionic Gustatory Receptor for pH Identification Based on ZnSnO Nanofiber Synaptic Transistor

The development of physiology and neurological diseases is normally accompanied by the production of acidic changes, making it crucial to develop biosensing system to detect pH variations to prevent early organ lesions. Due to the electrical double layer at the electrolyte/nanowire interface, artificial synaptic transistors can sensitively detect the pH variations. However, few studies focus on monitoring pH variations of the body based on synaptic transistors. In this study, electrolyte-gated synaptic transistors were fabricated using zinc tin oxide (ZnSnO) nanowires as channel materials. The fabricated devices can successfully mimic the functionality of acid-sensing ion channels (ASICs) in biological synapses, including excitatory postsynaptic currents (EPSCs), paired-pulse facilitations (PPFs), and short-term potentiations (STPs) under acidic conditions. Furthermore, ${3}\times {3}$ ZnSnO synaptic transistor arrays were constructed to monitor acid stimulations of diverse intensities and different regions to mimic the tongue ability of human. This work can not only advance the understanding of ASIC functionality in artificial synaptic devices, but also provide a novel approach to develop bioinspired taste-sensing systems with integrated sensing and memory capabilities.