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The unique properties of zinc oxide nanoparticles (ZnO-NPs) produced using plant extract make them attractive for use in medical as well as industrial applications, and it is necessary to develop environmentally friendly methods for their synthesis. This can be accomplished by replacing the traditional chemical compounds for the reduction of the zinc ions to ZnO-NPs during synthesis with natural plant extracts. Here, the biosynthesis of ZnO-NPs using Punica granatum (P. granatum) fruit peels extract was investigated as the reducing and stabilizing agent. The P. granatum /ZnO-NPs with spherical and hexagonal shapes were biosynthesized at different annealing temperatures. The X-ray diffraction analysis confirmed the synthesis of highly pure ZnO-NPs with increasing crystallinity in higher annealing temperatures. The ZnO-NPs displayed characteristic absorption peaks between 370 and 378 nm in the UV–vis spectra. Transmission electron microscopy (TEM) imaging showed the formation of mostly spherical and hexagonal-shaped ZnO-NPs in the mean size of 32.98 nm and 81.84 nm at 600 °C and 700 °C respectively. According to FTIR spectrum, strong absorption bands in the range of 462–487 cm−1 corresponding to Zn O bond stretching can be seen. Antibacterial activities of P. granatum /ZnO-NPs against Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) were investigated and compared. Results obtained show that smaller-sized P. granatum /ZnO-NPs are more effective in inhibiting growth of both bacteria. In addition, cytotoxicity assays were performed for P. granatum /ZnO-NPs against human colon normal and cancerous cells. P. granatum /ZnO-NPs exhibited similar killing activities of both cell lines at the concentration of ≥31.25 μg/mL. The biosynthesized ZnO-NPs could offer potential applications in bio-medical field. Image 1 • ZnO nanoparticles were prepared using Punica granatum fruit peels extract by sol-gel and thermal decomposition methods. • The ZnO-NPs were characterized by XRD, UV–visible spectroscopy, TEM, FESEM, and FTIR. • P. granatum /ZnO-NPs exhibited excellent antibacterial activities against Escherichia coli and Enterococcus faecalis. [ABSTRACT FROM AUTHOR]

This paper presents a green, facile and rapid method to prepare magnetite/zeolite-nanocomposites (NCs) in one step procedure at ambient temperature. The powder X-ray diffraction (PXRD) pattern of iron oxide nanoparticles (NPs) with the sole zeolite showed the broadening of zeolite peaks attributed to the incorporation of Fe 3 O 4 . Field-emission scanning electron microscopy (FESEM) analysis depicted that the Fe 3 O 4 ‒NPs were formed on the surface of porous zeolite framework. Transmission electron microscopy (TEM) analysis displayed the Fe 3 O 4 nanoparticles (NPs) were mostly in spherical shape with a mean diameter and standard deviation of 2.40 ± 0.41 nm. The selected-area electron diffraction (SAED) pattern confirmed the presence of cubic Fe 3 O 4 phase. The vibrating sample magnetometer (VSM) results indicated the as-synthesized sample has a saturation magnetization of around 6.52 emu g −1 . The magnetite/zeolite-NCs can be considered as a low-cost alternative catalyst for oxygen reduction reaction (ORR) process. The electrochemical measurement showed that the performance of magnetite/zeolite-NCs towards the ORR increased as the scan rate increased from 20 mV s −1 to 500 mV s −1 . The ORR is a diffusion-controlled process in the alkaline medium. [ABSTRACT FROM AUTHOR]

Superparamagnetic magnetite nanocomposites (Fe 3 O 4 -NCs) were successfully synthesized, which comprised of montmorillonite (MMT) as matrix support, Kappaphycus alvarezii (SW) as bio-stabilizer and Fe 3 O 4 as filler in the composites to form MMT/SW/Fe 3 O 4 -NCs. Nanocomposite with 0.5 g Fe 3 O 4 (MMT/SW/0.5Fe 3 O 4) was selected for anticancer activity study because it revealed high crystallinity, particle size of 7.2 ± 1.7 nm with majority of spherical shape, and M s = 5.85 emu/g with negligible coercivity. Drug loading and release studies were carried out using protocatechuic acid (PCA) as the model for anticancer drug, which showed 19% and 87% of PCA release in pH 7.4 and 4.8, respectively. Monolayer anticancer assay showed that PCA-loaded MMT/SW/Fe 3 O 4 (MMT/SW/Fe 3 O 4 -PCA) had selectivity towards HCT116 (colorectal cancer cell line). Although MMT/SW/Fe 3 O 4 -PCA (0.64 mg/mL) showed higher IC 50 than PCA (0.148 mg/mL) and MMT/SW/Fe 3 O 4 (0.306 mg/mL, MMT/SW/Fe 3 O 4 -PCA showed more effective killing towards tumour spheroid model generated from HCT116. The IC 50 for MMT/SW/Fe 3 O 4 -PCA, MMT/SW/Fe 3 O 4 and PCA were 0.132, 0.23 and 0.55 mg/mL, respectively. This suggests the improved penetration efficiency and drug release of MMT/SW/Fe 3 O 4 -PCA towards HCT116 spheroids. Moreover, concentration that lower than 2 mg/mL MMT/SW/Fe 3 O 4 -PCA did not result any hemolysis in human blood, which suggests them to be ideal for intravenous injection. This study highlights the potential of MMT/SW/Fe 3 O 4 -NCs as drug delivery agent. [ABSTRACT FROM AUTHOR]

In this study, a comparative study of effect using honey on copper nanoparticles (Cu-NPs) via simple, environmentally friendly process and inexpensive route was reported. Honey and ascorbic acid act as stabilizing and reducing agents with the assistance of sonochemical method. The products were characterized using UV–visible (UV–vis) spectroscopy, X-Ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), Field-Emission Scanning Electron Microscopy (FESEM) and Fourier Transform Infrared (FTIR) spectroscopy. The reddish brown colour demonstrated the formation of Cu-NPs and UV–visible proved the plasmon resonance of Cu-NPs. XRD also confirmed a highly pure Cu-NPs obtained with absence of copper oxide in which the structure is crystalline. The spherical size of the Cu-NPs was acquire in the presence of honey which is 3.68 ± 0.78 nm with narrow particle distribution. The antibacterial activity was seen against gram-positive and gram-negative bacteria which are Enterococcus faecalis (E. faecalis) and Escherichia coli (E. coli). At higher concentration of Cu-NPs, they were more effective in killing both bacteria. The Cu-NPs without and with honey exhibited toxicities toward normal and cancerous cells. However, Cu-NPs without honey showed more potent killing activity against normal and cancer cells. Unlabelled Image • Honey as capping and reducing agent for Cu-NPs • Ultrasonic irradiation assistance reduced the time of reaction. • Cu-NPs show potential antibacterial against gram positive and negative bacteria. • Cytotoxic of Cu-NPs toward CCD 112 and HCT 116 are reported in this study. [ABSTRACT FROM AUTHOR]

In this research, gold nanoparticles (Au-NPs) are biosynthesized from tetrachloroaurate (AuCl4−) aqueous solution through a simple and ecofriendly route using water extract of black Camellia sinensis leaf (C. sinensis L.) which acted as a reductant and stabilizer simultaneously. The prepared gold nanoparticles are characterized using UV-visible spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Also, determination of the accurate predictor model for chemical reactions is particularly important because of high cost of the chemical materials and measurement devices. While the artificial neural networks (ANNs) are one of the appropriate tools to forecast any phenomena, due to the low number of data set related to chemical experimental was caused to provide appropriate model is a time-consuming iterative process. With the aim to improve the accuracy of the ANN model and overcome the local convergence of this problem, a global search technique, biogeography-based optimization (BBO) method which integrated by chaotic map is employed. The improved model showed minimum mean squared error (MSE) of 0.0134 and maximum coefficient of determination (R2) equal to 0.9822 compared with several other famous ANN training algorithm, utilizing output experimental data obtained from biosynthesis proceeding. [ABSTRACT FROM AUTHOR]

Background: Green approach in synthesizing metal nanoparticles has gain new interest from the researchers as metal nanoparticles were widely applied in medical equipment and household products. The use of plants in the synthesis of nanoparticles emerges as a cost effective and eco-friendly approach. A green synthetic route for the production of stable silver nanoparticles (Ag-NPs) by using aqueous silver nitrate as metal precursor and Artocarpus elasticus stem bark extract act both as reductant and stabilizer is being reported for the first time. Results: The resultant Ag-NPs were characterized by UV-vis spectroscopy, powder X-Ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infra-red (FT-IR). The morphological study by TEM and SEM shows resultant Ag-NPs in spherical form with an average size of 5.81 ± 3.80, 6.95 ± 5.50, 12.39 ± 9.51, and 19.74 ± 9.70 nm at 3, 6, 24, and 48 h. Powder X-ray diffraction showed that the particles are crystalline in nature, with a face-centered cubic structure. The FT-IR spectrum shows prominent peaks appeared corresponds to different functional groups involved in synthesizing Ag-NPs. Conclusions: Ag-NPs were synthesized using a simple and biosynthetic method by using methanolic extract of A. elasticus under room temperature, at different reaction time. The diameters of the biosynthesis Ag-NPs depended on the time of reaction. Thus, with the increase of reaction time in the room temperature the size of Ag-NPs increases. From the results obtained in this effort, one can affirm that A. elasticus can play an important role in the bioreduction and stabilization of silver ions to Ag-NPs. [ABSTRACT FROM AUTHOR]