Carbon composites with photo-allosteric switch for waterborne virus removal

Control of waterborne pathogens by chemical- and energy-intensive disinfection methods poses significant challenges in underdeveloped regions. Here, plant-derived photosensitive carbon composites with a photo-allosteric strategy are proposed as a novel approach for designing green and responsive systems for controllable capture and inactivation of viruses. A composite comprising porous carbon, gallic acid, ε-polylysine and curcumin was synthesized and exhibited dual functions. In the dark, electrostatic attractions from ε-polylysine chains and electron shuttle through the graphene-like carbon matrix enable rapid viral adsorption (> 6-log removal within 30 min). Under illumination, curcumin-triggered singlet oxygen (¹O₂) achieves effective virus inactivation (> 6-log removal within 10 min; > 7-log within 30 min) while simultaneously restoring active sites. Importantly, this in situ ¹O₂ further induces the conformational transitions of ε-polylysine into compact, oxidation-resistant structures, ensuring a sustained antiviral performance under the light-dark cycles and repeated viral challenges. By activating the intrinsic properties of plant-derived porous carbon, herbal extracts, and poly(amino acid)s, this work establishes a green, locally sourced water treatment strategy to ensure water biosafety. This photo-responsive interfacial engineering strategy also holds promise to develop materials for personal protective equipment and medical environments.