Superior sensitivity towards H2 gas was successfully achieved with Pt-decorated GaN nanowires (NWs) gas sensor. GaN NWs were fabricated via chemical vapor deposition (CVD) route. Morphology (field emission scanning electron microscopy and transmission electron microscopy) and crystal structure (high resolution X-ray diffraction) characterizations of the as-synthesized nanostructures demonstrated the formation of GaN NWs having a wurtzite structure, zigzaged shape and an average diameter of 30-166nm. The Pt-decorated GaN NWs sensor shows a high response of 250-2650% upon exposure to H2 gas concentration from 7 to 1000ppm respectively at room temperature (RT), and then increases to about 650-4100% when increasing the operating temperature up to 75°C. The gas-sensing measurements indicated that the Pt-decorated GaN NWs based sensor exhibited efficient detection of H2 at low concentration with excellent sensitivity, repeatability, and free hysteresis phenomena over a period of time of 100min. The large surface-to-volume ratio of GaN NWs and the catalytic activity of Pt metal are the most influential factors leading to the enhancement of H2 gas-sensing performances through the improvement of the interaction between the target molecules (H2) and the sensing NWs surface. The attractive low-cost, low power consumption and high-performance of the resultant decorated GaN NWs gas sensor assure their uppermost potential for H2 gas sensor working at low operating temperature.
Curcumin is more soluble in ethanol, dimethylsulfoxide, methanol and acetone than in water. In this study, nanocurcumin combined with 8 mT AC static magnetic field was used to enhance cellular uptake, bioavailability, and ultimate efficiency of curcumin against prostate cancer cell line (PC3), four bacteria strains (two Gram positive: Micrococcus luteus ATCC 9341, Staphylococcus aureus ATCC 29213 and two Gram negative: Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853), mammalian cell line (HEK) and human erythrocytes (RBC). The efficiency (E%) between IC50 of nanocurcumin combined with magnetic field (NANOCUR-MF) and control against PC3 was 35.93%, which is three times higher compared to curcumin combined with magnetic field (CUR-MF); i.e., 10.77%. However, their E% against HEK was not significant; 1.4% for NANOCUR-MF and 1.95% for CUR-MF. Moreover, depending in minimum bacterial concentration (MBC), the use of MF leads to a reduction of MBCs for all tested bacteria compared with control. The obtained results established the applicability of (MF) in enhancing cellular uptake for PC3 and tested bacteria strains by increasing the penetration of drug (nanocurcumin and parent curcumin) into cell with fixing mild cytotoxic profile for HEK and RBC.
Background Curcumin (diferuloylmethane) is a polyphenol derived from the plant Curcuma longa, commonly called turmeric. Extensive research over the last 50 years has demonstrated that these polyphenols play an important role in the maintenance of health and prevention of diseases, in addition to its therapeutic benefits such as anti-tumor, anti-inflammatory, and anti-oxidant activities. Materials and methods This study is devoted to the enhancement of the solubility and bioavailability of curcumin nanoparticles prepared by a process based on a wet-milling technique and then examine in vitro against prostate cancer cell line 3 (PC3), human embryonic kidney cell line (HEK), human erythrocytes (red blood cells (RBCs)), and against fourth different bacterial strains two gram-positive (Micrococcus luteus ATCC 9341, Staphylococcus aureus ATCC 29213), two gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853). Results The cell viability curve, the half maximal inhibitory concentration (IC50), and the minimum bactericidal concentration (MBC) were evaluated. Nanocurcumin displayed significant activity against cancer cell line (PC3) and low toxicity against normal cells (HEK) compared with parent curcumin in favor of PC3 (P 0.05). On the other hand, the results demonstrate that, the MBCs of nanocurcumin were lower than curcumin for all different bacterial strains. Moreover, the selected gram-positive bacteria had higher sensitivity than the selected gram-negative bacteria for both curcumin and nanocurcumin. In conclusion, all these findings not only indicate that nanocurcumin safe compound has a potent ability as anti-cancer and antimicrobial activities, but also well justify the avail of using nanocurcumin as prostate cells PC3 anti-cancer, and antimicrobial agent for nanocurcumin are markedly improved by decreasing particle size to the nano-scale regime.
Ti-doped ZnO nanorod arrays were grown onto Si substrate using chemical bath deposition (CBD) method at 93 °C. To investigate the effect of time deposition on the morphological, and structural properties, four Ti-doped ZnO samples were prepared at various deposition periods of time (2, 3.5, 5, and 6.5 h). FESEM images displayed high-quality and uniform nanorods with a mean length strongly dependent upon deposition time; i.e. it increases for prolonged growth time. Additionally, EFTEM images reveal a strong erosion on the lateral side for the sample prepared for 6.5 h as compared to 5 h. This might be attributed to the dissolution reaction of ZnO with for prolonged growth time. XRD analysis confirms the formation of a hexagonal wurtzite-type structure for all samples with a preferred growth orientation along the c-axis direction. The (100) peak intensity was enhanced and then quenched, which might be the result of an erosion on the lateral side of nanorods as seen in EFTEM. This study confirms the important role of growth time on the morphological features of Ti-doped ZnO nanorods prepared using CBD.
Nickel-substituted copper ferrite nanoparticles (NP) (Cu1-xNixFe2O4) were prepared using a cost-effective hydrothermal method. X-ray diffraction (XRD) pattern revealed a single-phase cubic spinel structure. The increase in lattice parameters and decrease in crystallite size are associated with the replacement of Cu ions by Ni ions in the host lattice of copper ferrite. The optimized Cu0.95Ni0.05Fe2O4 composition was subsequently annealed at 750 °C and 850 °C for further studies. Fourier transform infrared (FT-IR) analysis shows the existence of two promising fundamental adsorption peaks at 465 and 582 cm-1, related to the metal ion stretching vibrations at the tetrahedral (A) and octahedral (B) sites, respectively. The local disorder at both the A and B sublattices upon the incorporation of Ni was observed from the Raman analysis. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) images shows the formation of agglomerates composed of nano-sized spherical particles. A high Barrett-Joyner-Halenda (BJH) surface area was achieved 17.25 m2/g with a particle stability of -11.1 mV obtained by the zeta potential. Both the dielectric loss and dielectric constant are decreased, whereas the AC conductivity gets increased with increasing frequency. The magnetization-field hysteresis curves exhibited ferromagnetic behavior with a pseudo-single domain, and the cyclic voltammetry study revealed a pseudocapacitive trend. This study highlights the importance of Ni substitution to control the physicochemical properties of spinel-phase CuFe2O4 for diverse applications, such as energy storage and lithium-ion batteries.