Synthesis and characterization of phenothiazine sensor for spectrophotometric and fluorescence detection of cyanide.

A sensitive and selective phenothiazine-based sensor (PTZ) has been successfully synthesized. The sensor PTZ displayed specific identification of CN- 'turn-off' fluorescence responses with a quick reaction and strong reversibility in an acetonitrile:water (90:10, V/V) solution. The sensor PTZ for detecting CN- exhibits the marked advantages of quenching the fluorescence intensity, fast response time (60 s), and low value of the detection limit. The concentration that is authorized for drinking water by the WHO (1.9 µM) is far higher than the detection limit, which was found to be 9.11 × 10-9 . The sensor displays distinct colorimetric and spectrofluorometric detection for CN- anion due to the addition of CN- anion to the electron-deficient vinyl group of PTZ, which reduces intramolecular charge transfer efficiencies. The 1:2 binding mechanism of PTZ with CN- was validated by fluorescence titration, Job's plot, HRMS, 1 H NMR, FTIR analysis, and density functional theory (DFT) investigations, among other methods. Additionally, the PTZ sensor was successfully used to precisely and accurately detect cyanide anions in actual water samples.

Synthesis and Biological Evaluation of Novel Imidazole Derivatives as Antimicrobial Agents.

Imidazole derivatives are considered potential chemical compounds that could be therapeutically effective against several harmful pathogenic microbes. The chemical structure of imidazole, with a five-membered heterocycle, three carbon atoms, and two double bonds, tends to show antibacterial activities. In the present study, novel imidazole derivatives were designed and synthesized to be evaluated as antimicrobial agents owing to the low number of attempts to discover new antimicrobial agents and the emerging cases of antimicrobial resistance. Two imidazole compounds were prepared and evaluated as promising candidates regarding in vitro cytotoxicity against human skin fibroblast cells and antimicrobial activity against several bacterial strains. The synthesized imidazole derivatives were chemically identified using nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR). The results demonstrated a relatively high cell viability of one of the imidazole derivatives, i.e., HL2, upon 24 and 48 h cell exposure. Both derivatives were able to inhibit the growth of the tested bacterial strains. This study provides valuable insight into the potential application of imidazole derivatives for treating microbial infections; however, further in vitro and in vivo studies are required to confirm their safety and effectiveness.

Green Synthesis and Antibacterial Activity of Ag/Fe2O3 Nanocomposite Using Buddleja lindleyana Extract.

In the study reported in this manuscript, silver/iron oxide nanocomposites (Ag/Fe2O3) were phytosynthesized using the extract of Buddleja lindleyana via a green, economical and eco-friendly strategy. The biosynthesized Ag/Fe2O3 nanocomposites were characterized using UV-Vis spectrophotometry, FTIR, XRD, TEM, DLS and SEM-EDX analyses. The particulates showed a triangular and spherical morphology having sizes between 25 and 174 nm. FTIR studies on the nanoparticles showed functional groups corresponding to organic metabolites, which reduce and stabilize the Ag/Fe2O3 nanocomposite. The antimicrobial efficacy of the phytosynthesized Ag/Fe2O3 against bacterial pathogens was assessed. In addition, Ag/Fe2O3 exhibited broad spectrum activities against B. subtilis, S. aureus, E. coli, and P. aeruginosa with inhibition zones of 23.4 ± 0.75, 22.3 ± 0.57, 20.8 ± 1.6, and 19.5 ± 0.5 mm, respectively. The Ag/Fe2O3 composites obtained showed promising antibacterial action against human bacterial pathogens (S. aureus, E. coli, B. subtilis and P. aeruginosa), making them candidates for medical applications.