Carbon Dot-Engineered Graphene Oxide–Silver Nanoparticle Nanocomposites Orchestrate Conductivity–Redox Coupling for Neuronal Regeneration

Oxidative stress-induced disruption of neuronal signaling remains a central barrier in the treatment of neurological disorders, where excessive reactive oxygen species (ROS) compromise ion channel function, synaptic transmission, and neuronal differentiation. Although conductive nanomaterials such as graphene oxide–silver nanoparticles (GO–AgNPs) have shown promise in promoting neurite outgrowth and neuronal maturation, their application is limited by structural instability and burst silver ion (Ag+) release under oxidative conditions. Here, we introduce a carbon dot (CD)-enabled strategy to stabilize conductive GO–Ag nanocomposites via green, in situ integration of folic acid-derived nitrogen-doped CDs. This design transforms conventional GO–AgNPs into a redox-active, self-regulating conductive platform, GO-CD–AgNPs (GC–AgNPs), that simultaneously enhances electrical stability and mitigates oxidative damage. GC–AgNPs exhibit sustained electrical conductivity under oxidative stress and markedly enhanced radical scavenging capacity. In SH-SY5Y cells, GC–AgNPs significantly reduce cytotoxicity by preventing superoxide overproduction and intracellular Ca2+ overload. Under oxidative stress, these nanocomposites promote neuronal maturation, as evidenced by increased expression of MAP2 and NF-H. In addition, GC–AgNPs suppress pro-inflammatory cytokine secretion in HMC3 microglia, demonstrating concurrent immunomodulatory effects. Collectively, by resolving the intrinsic coupling between conductivity and oxidative stability, this work establishes a design framework for redox-adaptive conductive biomaterials. This strategy provides a promising approach for designing electroactive biomaterials capable of maintaining neural network integrity in challenging pathological microenvironments.