Real-time sensing of Chemical Warfare Agents (CWAs) is today a crucial topic to prevent lethal effects of a chemical terroristic attack. For this reason, the development of efficient, selective, sensitive and reversible sensoristic devices, able to detect by optical response ppm levels of these compounds, both in water and in air, is strongly required. Here we report the design and synthesis of a fluorescent nanosensor, based on carbon nanoparticles covalently functionalized with ethanolamine arms, which exploits the multitopic supramolecular interaction with nerve agents, ensuring highly efficient (logK 6.46) and selective molecular recognition. Moreover, given the aqueous dispersibility of carbon nanoparticles, these nanosensors ensure even higher sensitivity, detecting sub-ppt concentration of nerve agents in water, and sub-ppm level in air by using a common digital camera or a smartphone. Our results pave the way to an innovative class of low-cost reusable CWA sensors prompting, for the first time, the simultaneous detection of nerve agents through gaseous and aqueous media, thus extending the protection range to public water supplies.

The thermocatalytic, photocatalytic and photothermo-catalytic oxidation of some volatile organic compounds (VOCs), 2-propanol, ethanol and toluene, was investigated over brookite TiO₂-CeO₂ composites. The multi-catalytic approach based on the synergistic effect between solar photocatalysis and thermocatalysis led to the considerable decrease in the conversion temperatures of the organic compounds. In particular, in the photothermo-catalytic runs, for the most active samples (TiO₂-3 wt% CeO₂ and TiO₂-5 wt% CeO₂), the temperature at which 90% of VOC conversion occurred was about 60 °C, 40 °C and 20 °C lower than in the thermocatalytic tests for 2-propanol, ethanol and toluene, respectively. Furthermore, the addition of cerium oxide to brookite TiO₂ favored the total oxidation to CO₂ already in the photocatalytic tests at room temperature. The presence of small amounts of cerium oxide allowed to obtain efficient brookite-based composites facilitating the space charge separation and increasing the lifetime of the photogenerated holes and electrons as confirmed by the characterization measurements. The possibility to concurrently utilize the photocatalytic properties of brookite and the redox properties of CeO₂, both activated in the photothermal tests, is an attractive approach easily applicable to purify air from VOCs.