Monolayer Amphiphiles Hydrophobicize MoS₂-Mediated Real-Time Water Removal for Efficient Waterproof Hydrogen Detection

Ensuring water-fouling-free operation of semiconductor-based gas sensors is essential to maintaining their accuracy, reliability, and stability across diverse applications. Despite the use of hydrophobic strategies to prevent external water intrusion, addressing in situ-produced water transport during H₂ detection remains a challenge. Herein, we construct a novel waterproof H₂ sensor by integrating single-atom Ru^(III) self-assembly with monolayer amphiphiles embedded in MoS₂. The unique monolayer structure enables the sensor to detect H₂ in the presence of water, as well as facilitate the self-transport of in situ-generated water from the H₂-O₂ reaction during H₂ detection. Molecular dynamics simulations reveal that monolayer amphiphiles exhibit a higher water diffusion coefficient than multilayer amphiphiles, making them more advantageous for removing in situ-produced water. Deployable on mobile platforms, it enables wireless H_2cat detection for up to 6 months, without the introduction of protective membranes against dust and water ingress. This work not only enhances the performance of H₂ detection but also introduces a new concept for the advancement of stable water-sensitive sensors.