Green Synthesis of Metal Nanoparticles with Borojó (Borojoa patinoi) Extracts and Their Application in As Removal in Water Matrix.

The predominant aim of the current research was to generate a proposal for the removal of arsenic, a highly toxic pollutant, encountered within the Papallacta Lagoon in Ecuador. The average concentrations of As yielded ranges between 18 to 652 µg/L, through the use of metallic nanoparticles. Sampling was performed in the lagoon with their respective geographic locations and "in situ" parameters. Nanoparticles of Mn3O4 NPs, Fe3O4 NPs, and CuO NPs were synthesized at a 0.5 M concentration, using the precipitation method, and borojó (Borojoa patinoi) extract was added as an anti-caking agent as well as antioxidant. The nanoparticles were characterized by visible spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. After arsenic removal treatment using nanoparticles, a randomized experimental design of different concentrations (5 mg/L, 10 mg/L, 25 mg/L, 50 mg/L, 100 mg/L, and 150 mg/L) was applied at laboratory level. The average diameter of Fe3O4NPs ranged from 9 nm to 36 nm, Mn3O4 NPs were 15-20 nm, and CuO NPs ranged from 25 nm to 30 nm. Arsenic removal percentages using Fe3O4 NPs with a concentration of 150 mg/L was 87%; with Mn3O4 NPs, the removal was 70% and CuO NPs of about 63.5%. Finally, these nanoparticles could be used in a water treatment plant for the Papallacta Lagoon.

Green synthesis of silver nanoparticles for application in cosmetics.

In this work, we analyzed the advantages of using silver nanoparticles (AgNPs) synthesized with natural extracts in ultraviolet-visible spectroscopy (UV-Vis) protective cream. The photodegradation properties of the new UV-Vis protective milk show an increase in its absorption band compared to AgNP-free cream. Previous to the study of the AgNPs mixed within the body milk, we studied the optical UV-Vis properties of extracts at different collection times, as they can influence the spectral range of UV-Vis absorption of the hybrid compound (AgNPs + natural extract). Shape and size of the AgNPs differs from the type of reducing agent as well as the concentration of silver nitrate used. We also compared the cytotoxicity in cell lines and the antibacterial effect of the AgNPs without and with organic coating. All these studies showed that we obtained hybrid sun-protective body milk with a high degree of solar protection and with low cytotoxicity at a cellular level, thus improving its protective properties. The synthetized hybrid compound could be a possible cost-affordable alternative for the market.