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, which are able to detect by optical response the 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 (log K 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 subppm 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.

This work attempts to produce photocatalytic surfaces for large-scale applications by depositing nanostructured coatings on polymeric substrates. ZnO/poly(methyl methacrylate) (PMMA) composites were prepared by low-temperature atomic layer deposition (ALD) of ZnO on PMMA substrates. In addition, to increase the photocatalytic and antibacterial activities of ZnO films, Ag nanoparticles were added on ZnO surfaces using plasma-enhanced ALD. The morphology, crystallinity, and chemical composition of the specimens were meticulously examined by scanning and transmission electron microscopies, energy-dispersive Xray spectroscopy, and X-ray diffraction analyses. The noteworthy photocatalytic activity of the nanocomposites was proved by the degradation of the following organic pollutants in aqueous solution: methylene blue, paracetamol, and sodium lauryl sulfate. The antibacterial properties of the samples were tested using Escherichia coli as a model organism. Moreover, the possible toxic effects of the specimens were checked by biological tests. The present results unambiguously indicate the Ag/ZnO/PMMA nanocomposite as a powerful tool for an advanced wastewater treatment technology.

In this work we report a technique for the preparation of AuxNi1-x alloy nanoparticles based on pulsed laser irradiation in liquid of Au and Ni@NiO colloidal mixtures. The structural and compositional characterization of the obtained materials, performed through X-ray diffraction and transmission electron microscopy coupled with energy dispersive X-ray spectroscopy, has shown a correlation between the final alloy composition and the different Au to Ni@NiO ratio in the irradiated mixture. With the support of theoretical calculations, we propose as possible mechanism for the formation of the alloy structures a temperature increase, enhanced by the strong absorption of gold surface plasmon resonance at resonant wavelength, and a subsequent melting of the structures. Optical characterization through UV-vis spectroscopy and magnetic characterization through SQUID magnetometry confirm a coexistence of the plasmonic and magnetic behaviors in the hybrid systems. In view of such results, AuxNi1-x alloy nanoparticles could be a promising base material for devices requiring both plasmonic and magnetic properties

Fluorescent carbon quantum dots (CDs) are synthesized and employed as fluorescent nanochemosensors for selective detection of amino acids. A detailed investigation of excitation−emission maps revealed that the fluorescence properties of CDs are intensely and strongly influenced by the interaction at the surface with different amino acids. The discrimination capability was demonstrated by tensor rank decomposition of the differences induced by the surface reaction in the excitation−emission maps and by means of a common machine learning approach based on artificial neural networks.

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