One-pot facile synthesis of hexagonal Bi2Te3 nanosheets and its novel nanocomposites: Characterization, anticancer, antibacterial, and antioxidant activities.

Bismuth Telluride (Bi2Te3) layered structure results in extraordinary features in diagnostic and therapeutic applications. However, Bi2Te3 synthesis with reliable stability and biocompatibility in biological systems was the major challenge that limited its biological application. Herein, reduced graphene oxide (RGO) or graphitic carbon nitride (CN) nanosheets were incorporated into Bi2Te3 matrix to improve exfoliation. Bi2Te3 nanoparticles (NPs) and its novel nanocomposites (NCs): CN@Bi2Te3 and CN-RGO@Bi2Te3 were solvothermally synthesized, physiochemically characterized and assessed for their anticancer, antioxidant, and antibacterial activities. X-ray diffraction depicted Bi2Te3 rhombohedral lattice structure. Fourier-transform infrared and Raman spectra confirmed NC formation. Scanning and transmission electron microscopy revealed 13 nm thickness and 400-600 nm diameter of hexagonal, binary, and ternary nanosheets of Bi2Te3-NPs/NCs. Energy dispersive X-ray Spectroscopy revealed the presence of Bi, Te, and carbon atoms in the tested NPs with negatively charged surfaces as depicted by zeta sizer. CN-RGO@Bi2Te3-NC displayed the smallest nanodiameter (359.7 nm) with the highest Brunauer-Emmett-Teller surface area and antiproliferative activity against MCF-7, HepG2 and Caco-2. Bi2Te3-NPs had the greatest scavenging activity (96.13 ± 0.4%) compared to the NCs. The NPs inhibitory activity was greater against Gram-negative bacteria than that of Gram-positive bacteria. Integration of RGO and CN with Bi2Te3-NPs enhanced their physicochemical properties and therapeutic activities giving rise to their promising capacity for future biomedical applications.

Efficient removal of bovine serum albumin from water by cellulose acetate membranes modified with clay and titania nano particles.

Modified cellulose acetate membranes with bentonite clay (CA/bent) and TiO2 nanoparticles (CA/TiO2) using the phase inversion method are successfully prepared and characterized. These Membranes are favored due to their high salt rejection properties and recyclability. The IR and EDX spectral data indicate the formation of modified membranes. The Scan Electron Microscope micrographs show that the modified membranes have smaller particle sizes with higher porosity than the neat membrane. The average pore diameter is 0.31 µm for neat cellulose acetate membrane (CA) and decreases to 0.1 µm for CA/0.05bent. All modified membranes exhibit tensile strengths and elongation percentages more than the neat membrane. The higher tensile strength and the maximum elongation% are 15.3 N/cm2 and 11.78%, respectively, for CA/0.05bent. The thermogravimetric analysis of modified membranes shows higher thermal stability than the neat membrane. The modified membranes exhibit enhanced wettability and hydrophilicity compared with cellulose acetate, by measuring the contact angle which decreases from 60° (CA) to 40° (CA/0.1bent). The ultrafiltration tests indicated that the CA/bent and CA/TiO2 are better than CA. The most efficient nanocomposite membrane is CA/0.05bent with 100% removal of (BSA) from industrial water with a flux equal to 9.5 mL/min under an applied pressure of 20 bar. Thus, this study introduces a novel ultrafiltration membrane (CA/0.05bent) that can be used effectively to completely remove bovine serum albumin from contaminated water.

Synthesis, Structure and Biological Evaluations of Zn(II) Pincer Complexes Based on S-Triazine Type Chelator.

2,4-bis (3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPMT) pincer ligand was used to synthesize the new [Zn(BPMT)(NCS)2] (1) and [Zn(BPMT)(Br)2] (2) complexes by a reaction with Zn(NO3)2·6H2O in the presence of either KSCN or KBr, respectively. The structure of complex 1 has been exclusively confirmed using single crystal X-ray diffraction. In this neutral heteroleptic complex, the BPMT is a pincer chelate coordinating the Zn(II) ion via three interactions with the two pyrazole moieties and the s-triazine core. Hence, BPMT is a tridentate NNN-chelate. The coordination environment of Zn(II) is completed by two strong interactions with two terminal SCN- ions via the N-atom. Hence, the Zn(II) is penta-coordinated with a distorted square pyramidal coordination geometry. Hirshfeld analysis indicated the predominance of H…H, H…C and N…H intermolecular interactions. Additionally, the S…H, S…C and S…N contacts are the most significant. The free ligand has no or weak antimicrobial, antioxidant and anticancer activities while the studied Zn(II) complexes showed interesting biological activity. Complex 1 has excellent antibacterial activity against B. subtilis (2.4 µg/mL) and P. vulgaris (4.8 µg/mL) compared to Gentamycin (4.8 µg/mL). Additionally, complex 1 (78.09 ± 4.23 µg/mL) has better antioxidant activity than 2 (365.60 ± 20.89 µg/mL). In addition, complex 1 (43.86 ± 3.12 µg/mL) and 2 (30.23 ± 1.26 µg/mL) have 8 and 12 times the anticancer activity of the free BPMT ligand (372.79 ± 13.64 µg/mL).