Plasma-guided green synthesis of crystalline graphene quantum dots for broad-spectrum antiviral applications

The rapid mutation of viruses and rising resistance to conventional antivirals necessitate the development of mechanism-informed, broad-spectrum nanotherapeutics. Here, we report a sustainable plasma-assisted strategy to synthesize graphene quantum dots (GQDs) with tunable crystallinity and surface functionalities for universal antiviral applications. By tailoring the precursor chemistry under ambient microplasma conditions, we uncover a structure–activity–mechanism correlation linking graphitic domain ordering to viral inhibition. The optimized GQDs exhibit enhanced π–π stacking and electrostatic interactions with viral surface proteins, as confirmed by photoluminescence quenching, zeta potential shifts, and transmission electron microscopy (TEM). Systematic spectroscopy study further supports multivalent binding to HSV-1 cells. The resulting GQDs demonstrate potent, broad-spectrum inhibition against both enveloped (HSV-1, SARS-CoV-2 pseudovirus, DENV-2) and non-enveloped (EV71, EMCV) viruses, as well as two distinct HSV-1 strains, with negligible cytotoxicity. The antiviral effect arises from multivalent, non-specific interactions with viral surface proteins, rendering the mechanism broadly applicable. This work establishes a scalable platform for rational nanomaterial design and highlights the utility of plasma-engineered GQDs in next-generation broad-spectrum antiviral applications.