Neurotrophic and Antioxidative Ionogel-Gated Synaptic Transistor for Biofunctional Neuromorphic Systems

Electrolyte-gated synaptic transistors (EGSTs) offer strong potential for bioimplantable neuromorphic devices due to the direct applicability of biocompatible electrolytes, but their device-level biocompatibility assessments and the use of therapeutically beneficial electrolytes remain largely unexplored. Herein, we introduce an EGST gated by a neuroactive-cytoprotective matrix (NCM) ionogel, a glutathione-functionalized gelatin hydrogel loaded with nerve growth factor (NGF), combined with an indium–gallium–zinc oxide semiconductor channel. Ellman’s assay confirms the abundant thiol groups indicative of antioxidative potential, while NGF-mediated cell proliferation reaches 2001.08% after 5 d, validating the neurotrophic functionality of the NCM ionogel. When integrated into an EGST configuration, the device reliably reproduces essential synaptic behaviors, including a paired-pulse facilitation index of 131.86% and stable retention of 32 conductance states over 2048 pulsing events. Artificial neural network simulations further achieve a recognition accuracy of 88.17% after 125 training epochs. Cytotoxicity testing demonstrates excellent device-level biocompatibility, with 126.44% relative cell viability after 3 days, establishing the NCM ionogel-gated EGST as a promising candidate for next-generation bioimplantable computing platforms.