One-Step Fabrication of N,S-Codoped Carbon Dots from Acronicta major Larva: Structural Characterization and Sedative–Hypnotic Mechanisms

The <i>Acronicta major</i> larva is a toxic agricultural pest that poses severe ecological management challenges. This study presents a sustainable strategy to valorize this hazardous biological waste into functional nanotherapeutics for insomnia by leveraging its unique intrinsic chemical composition. Carbon dots derived from <i>Acronicta major</i> larva (AM-CDs) were synthesized via one-step pyrolysis, which facilitated the natural molecular pre-assembly of N,S-codoping. Their physicochemical properties and cytotoxicity were evaluated using a series of characterizations and the CCK-8 assay. The sedative and hypnotic effects were assessed in mice with PCPA-induced insomnia through hot plate, Open Field and pentobarbital-induced sleep tests, and their potential mechanism was explored via neurotransmitter detection. The thermal process effectively eliminated intrinsic toxicity while retaining bioactivity via in situ heteroatom doping. AM-CDs exhibited favorable biocompatibility and significant sedative-hypnotic activity, reducing anxiety-related agitation without motor impairment. Mechanistically, AM-CDs effectively restored the GABA/5-HT/glutamate axis. Unlike direct central receptor binding, our findings suggest that this therapeutic effect is likely mediated through a systemic or peripheral regulatory pathway. This study demonstrates the conversion of toxic pests into safe and intrinsically bioactive nanomaterials, providing a dual solution for ecological pest management and novel neuroactive agent development, and validating the "Waste-to-Wealth" concept in biomedicine.