Near-Room-Temperature Ethanol Detection Using Ag-Loaded Mesoporous Carbon Nitrides

Development of room-temperature gas sensors is a much sought-after aspect that has fostered research in realizing new two-dimensional materials with high surface area for rapid response and low-ppm detection of volatile organic compounds (VOCs). Herein, a fast-response and low-ppm ethanol gas sensor operating at near room temperature has been fabricated successfully by utilizing cubic mesoporous graphitic carbon nitride (g-CN, commonly known as g-C₃N₄), synthesized through template inversion of mesoporous silica, KIT-6. Upon exposure to 50 ppm ethanol at 250 °C, the optimized Ag/g-CN showed a significantly higher response (<i>R</i>_a/<i>R</i>_g = 49.2), fast response (11.5 s), and full recovery within 7 s in air. Results of sensing tests conducted at 40 °C show that the sensor exhibits not only a highly selective response to 50 ppm (<i>R</i>_a/<i>R</i>_g = 1.3) and 100 ppm (<i>R</i>_a/<i>R</i>_g = 3.2) of ethanol gas but also highly reversible and rapid response and recovery along with long-term stability. This outstanding response is due to its easily accessible three-dimensional mesoporous structure with higher surface area and unique planar morphology of Ag/g-CN. This study could provide new avenues for the design of next-generation room-temperature VOC sensors for effective and efficient monitoring of alarming concern over indoor environment

Synthesis and evaluation of antibacterial and antioxidant activity of novel 2-phenyl-quinoline analogs derivatized at position 4 with aromatically substituted 4<i>H</i>-1,2,4-triazoles

<p>A set of novel quinolone–triazole conjugates (<b>12</b>–<b>31</b>) were synthesized in three steps in good yields starting from 2-phenylquinoline-4-carboxylic acid. All the intermediates, as well as the final 1,2,4-triazolyl quinolines were fully characterized by their detailed spectral analysis utilizing different techniques such as IR, ¹H NMR, ¹³C NMR, and finally mass spectrometry. All the synthesized compounds were evaluated <i>in vitro</i> for their potential antibacterial activity and their preliminary safety profile was assessed through cytotoxicity assay. Additionally, six selected conjugates were evaluated for their antioxidative properties on the basis of density functional theory calculations, using radical scavenging assay (DPPH) and cellular antioxidant assay. The reported results encourage further investigation of selected compounds and are shading light on their potential pharmacological use.</p