Novel Dy2O3/ZnO-Au ternary nanocomposites: Green synthesis using pomegranate fruit extract, characterization and their photocatalytic and antibacterial properties.

In this study for the first time, high efficient, eco-friendly and novel Dy2O3/ZnO-Au ternary nanocomposites (Dy/ZnO-AuNCs) were prepared in presence of pomegranate fruit (PF) extract as capping and reducing agents (Dy/ZnO-AuNCs@PF). The influence of various parameters such as basic agents, reducing agents, sonication power, and sonication time were performed to reach the optimum condition. The formation of the products was characterized by FT-IR, HRTEM, XRD, FE-SEM, TEM, EDX and DRS techniques. The XRD and TEM analysis showed that the morphology and crystallite size of nanocomposites were spherical morphology and 85-90 nm, respectively. The obtained Dy/ZnO-AuNCs@PF were investigated as a nanocatalyst for degradation of erythrosine (ES) as anionic dye and basic violet 10 (BV10) as cationic dye under UV and visible light irradiations. The Dy/ZnO-AuNCs@PF exhibited higher photodegradation against ES (89.6%) and BV10 (91.3%) than pure Dy2O3 (63.1% for ES, 66.5% for BV10) and Dy2O3/ZnO (64.5% for ES, 70.8% for BV10) under UV irradiation. It was found that gold nanoparticles have significant effect on Dy/ZnO-AuNCs@PF catalytic performance for decomposition of organic pollutants. In addition, Dy/ZnO-AuNCs@PF showed excellent in-vitro antibacterial activity against A. baumannii, S. aureus and P. mirabilis with MIC and MBC values of (5, 80 mg/ml), (5, 40 mg/ml) and (2.5, 20 mg/ml), respectively. Generally, according to its excellent antibacterial and catalytic activity, Dy/ZnO-AuNCs@PF can be used in biomedical and environmental applications.

Engineered mixed oxide-based polymeric composites for enhanced antimicrobial activity and sustained release of antiretroviral drug.

Here, pH-responsive engineered polymeric composites were fabricated from sodium alginate and mixed Cu/Zn oxides. The resulting alginate-CuxZn1-xO composites were characterized by FTIR, SEM and XRD, then used as an efficient carrier for the antiretroviral drug (zidovudine, AZT) and exhibited remarkable antibacterial properties. The resulting polymeric composites had specific surface areas of 185.2-198.6 m2/g as confirmed by the Brunauer-Emmett-Teller analysis. The metal oxide distribution within the alginate matrix was confirmed from the X-ray diffraction and scanning electron microscopy analyses. The zidovudine, an antiretroviral drug was encapsulated in 30 mg of alginate-Cu0.7Zn0.3O with 68% encapsulation efficiency. The release of AZT in simulated intestinal fluid (pH 7.4) was studied, a slow and sustained release of AZT (~96.2%) was observed. The AZT release kinetics is sufficiently described by the Korsmeyer-Peppas model and follows the Fickian transport profile. Results herein demonstrated that A-Cu0.7Zn0.3O, A-Cu0.3Zn0.7O and Cu0.5Zn0.5O exhibited excellent bacterial devastation property. A dose of 8 µg/mL A-Cu0.7Zn0.3O and 13 µg/mL A-Cu0.3Zn0.7O are sufficient to completely killed E. coli DH5a and S. aureus NSUHS-151 within 24 h.