Nitroaromatic explosives are the most common explosives, and their detection is important to public security, human health, and environmental protection. In particular, the detection of solid explosives through directly revealing the presence of their vapors in air would be desirable for compact and portable devices. In this study, amino-functionalized carbon nanotubes were used to produce resistive sensors to detect nitroaromatic explosives by interaction with their vapors. Devices formed by carbon nanotube networks working at room temperature revealed trinitrotoluene, one of the most common nitroaromatic explosives, and di-nitrotoluene-saturated vapors, with reaction and recovery times of a few and tens of seconds, respectively. This type of resistive device is particularly simple and may be easily combined with low-power electronics for preparing portable devices.

Atomically thin molybdenum disulfide (MoS₂) is a two-dimensional semiconductor with versatile applications. The recent adoption of liquid molybdenum precursors in chemical vapor deposition has contributed significantly to the reproducible wafer-scale synthesis of MoS₂ monolayer and few-layer films. In this work, we study the effects of the carrier gas flow rate on the properties of two-dimensional molybdenum disulfide grown by liquid-precursor-intermediate chemical vapor deposition on SiO₂/Si substrates. We characterized the samples using Optical Microscopy, Scanning Electron Microscopy, Raman spectroscopy, and Photoluminescence spectroscopy. We analyzed samples grown with different nitrogen carrier flows, ranging from 150 to 300 sccm, and discussed the effect of carrier gas flows on their properties. We found a correlation between MoS₂ flake lateral size, shape, and number of layers, and we present a qualitative growth model based on changes in sulfur provision caused by different carrier flows. We show how the use of liquid precursors can allow for the synthesis of homogeneous, single-layer flakes up to 100 µm in lateral size by optimizing the gas flow rate. These results are essential for gaining a deeper understanding of the growth process of MoS₂.

Tissue engineering (TE) and nanomedicine require devices with hydrophilic surfaces to better interact with the biological environment. This work presents a study on the wettability of cubic silicon-carbide-based (SiC) surfaces. We developed four cubic silicon-carbide-based epitaxial layers and three nanowire (NW) substrates. Sample morphologies were analyzed, and their wettabilities were quantified before and after a hydrogen plasma treatment to remove impurities due to growth residues and enhance hydrophilicity. Moreover, sample biocompatibility has been assessed with regard to L929 cells. Our results showed that core–shell nanowires (SiO₂/SiC NWs), with and without hydrogen plasma treatment, are the most suitable candidate material for biological applications due to their high wettability that is not influenced by specific treatments. Biological tests underlined the non-toxicity of the developed biomaterials with regard to murine fibroblasts, and the proliferation assay highlighted the efficacy of all the surfaces with regard to murine osteoblasts. In conclusion, SiO₂/SiC NWs offer a suitable substrate to develop platforms and membranes useful for biomedical applications in tissue engineering due to their peculiar characteristics.