Yasair S. S. Al-Fayiz

In this work, acid-functionalized multiwalled carbon (MWCNTs–CO2H) nanotube was successfully functionalized with a heterocyclic scaffold, namely benzimidazole, to give novel functionalized multiwalled carbon nanotubes (BI@MWCNTs). Then, FTIR, XRD, TEM, EDX, Raman spectroscopy, DLS, and BET analyses were used to characterize the synthesized BI@MWCNTs. The effectiveness of the adsorption of two heavy metal ions, Cd2+ and Pb2+, in single metal and mixed metal solutions on the prepared material was investigated. Influencing parameters for the adsorption method, for example duration, pH, starting metal concentration, and BI@MWCNT dosage, were examined for both metal ions. Moreover, adsorption equilibrium isotherms fit with the Langmuir and Freundlich models perfectly, while the intra-particle diffusion models provide pseudo-second order adsorption kinetics. The adsorption of Cd2+ and Pb2+ ions onto BI@MWCNTs revealed an endothermic and a spontaneous method with great affinity as a result of the negative values of Gibbs free energy (ΔG) and the positive values of enthalpy (ΔH) and entropy (ΔS). Both Pb2+ and Cd2+ ions were completely eliminated from aqueous solution (100 and 98%, respectively) using the prepared material. Additionally, BI@MWCNTs have a high adsorption capacity and were regenerated in a simple way and reused for six cycles, which make them a cost-effective and efficient absorbent for the removal of such heavy metal ions from wastewater.

We report the design and synthesis of novel hydroxamic acid-tethered organoselenium (OSe) hybrids. Their antimicrobial and anticancer activities were assessed against different microbes (e.g., Candida albicans (C. albicans), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus)), as well as liver and breast carcinomas. OSe hybrid 8 showed promising anticancer activity, with IC50 = 7.57 ± 0.5 µM against HepG2 and IC50 = 9.86 ± 0.7 µM against MCF-7 cells. Additionally, OSe compounds 8 and 15 exhibited promising antimicrobial activities, particularly against C. albicans (IA% = 91.7 and 83.3) and S. aureus (IA% = 90.5 and 71.4). The minimum inhibitory concentration (MIC) assay confirmed the potential antimicrobial activity of OSe compound 8. OSe compounds 8 and 16 displayed good antioxidant activities compared to vitamin C in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. These results indicate that hydroxamic acid-based organoselenium hybrids have promising biological activities such as anticancer, antimicrobial, and antioxidant properties, especially compounds 8, 13, 15, and 16, which warrant further studies.