AIE Gemini Surfactant-Enabled Janus Membrane for All-In-One “Sampling–Detection–Elimination” of Airborne Pathogens

A single-material system that seamlessly combines bioaerosol sampling, subsequent pathogen detection, and on-demand inactivation represents a pivotal but unmet goal for intelligent environmental health monitoring. Herein, a Janus air filter membrane (AIE-LGFM) was developed with fully biobased lignin-gelatin for this specific purpose. This membrane is constructed through a green phase-separation process, forming a water-dissolvable and tunable porous network with a high interception efficiency (99.4%) and low pressure drop (40 mbar). Significantly, a gemini-type aggregation-induced emission (AIE) surfactant (G-MeOTTVP) was synthesized, featuring a symmetric cationic structure that confers superior surface activity and bacterial targeting ability, alongside strong near-infrared fluorescence emission (755 nm) and a high reactive oxygen species yield. This AIE gemini surfactant is asymmetrically coated onto the membrane, creating a Janus architecture that spatially separates its functions. The functionalized front side serves as a strong and light-activated bactericidal surface, while the pristine back side enables high-fidelity microbial capture for visual detection. The AIE-LGFM demonstrates outstanding field performance, accurately monitoring airborne microbes while enabling on-site photodynamic elimination. This work thus pioneers an eco-friendly and versatile membrane platform that unifies the all-in-one "sampling-detection-elimination" workflow, opening new avenues for intelligent management of airborne biological threats.