Plasmonic Membrane for TiO₂ Nanoparticles Activity Detection in Complex Environments

Abstract Titanium dioxide nanoparticles (TiO 2 NPs) are widely manufactured semiconductors, but their release into aquatic environments poses significant threats to ecosystems and human health. The environmental hazard associated with TiO 2 NPs in surface water primarily results from their photocatalytic activity, which generates reactive oxygen species (ROS). Addressing this challenge is crucial for ensuring the safe utilization of TiO 2 NPs and preserving the environment. In this study, we developed a novel plasmonic membrane comprising titanate nanowires (TiNWs) functionalized with silica‐coated gold nanostars (AuNSts) to probe, in situ, the capture and measurement of the photocatalytic activity of TiO 2 NPs in complex media such as seawater. This method represents a unique and precise approach to real‐time monitoring of the presence and photocatalytic activity of TiO 2 NPs, thereby laying the foundation for establishing an environmental risk parameter for these particles.