ABSTRACT
Silver selenide (Ag2Se) is a promising nanomaterial due to its outstanding optoelectronic properties and countless bio-applications. To the best of our knowledge, we report, for the first time, a simple and easy method for the ultrasound-assisted synthesis of Ag2Se nanoparticles (NPs) by mixing aqueous solutions of silver nitrate (AgNO3) and selenous acid (H2SeO3) that act as Ag and Se sources, respectively, in the presence of dissolved fructose and starch that act as reducing and stabilizing agents, respectively. The concentrations of mono- and polysaccharides were screened to determine their effect on the size, shape and colloidal stability of the as-synthesized Ag2Se NPs which, in turn, impact the optical properties of these NPs. The morphology of the as-synthesized Ag2Se NPs was characterized by transmission electron microscopy (TEM) and both α- and ß-phases of Ag2Se were determined by X-ray diffraction (XRD). The optical properties of Ag2Se were studied using UV-Vis spectroscopy and its elemental composition was determined non-destructively using scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS). The biological activity of the Ag2Se NPs was assessed using cytotoxic and bactericidal approaches. Our findings pave the way to the cost-effective, fast and scalable production of valuable Ag2Se NPs that may be utilized in numerous fields.
Subject(s)
Anti-Bacterial Agents/chemistry , Antineoplastic Agents/chemistry , Metal Nanoparticles/chemistry , Selenium Compounds/chemistry , Silver Compounds/chemistry , Sugars/chemistry , Anti-Bacterial Agents/pharmacology , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Escherichia coli/drug effects , Green Chemistry Technology , Humans , Polysaccharides/chemistry , Pseudomonas aeruginosa/drug effects , Salmonella typhimurium/drug effects , Selenious Acid/chemistry , Semiconductors , Silver Nitrate/chemistry , Staphylococcus aureus/drug effectsABSTRACT
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.
Subject(s)
Metal Nanoparticles/chemistry , Silver/chemistry , Anti-Bacterial Agents/chemistry , Cosmetics , Green Chemistry TechnologyABSTRACT
Latin American Creole chickens are generally not characterized; this is the case in Ecuador, where the lack of scientific information is contributing to their extinction. Here, we developed a characterization of the genetic resources of Ecuadorian chickens located in three continental agroecosystems (Pacific coastal, Andean, and Amazonian). Blood samples of 234 unrelated animals were collected in six provinces across Ecuador: Bolívar, Chimborazo, Cotopaxi, Guayas, Morona Santiago, and Tungurahua, in order to perform a genetic characterization and population structure assessment using the AVIANDIV project microsatellites panel (30 loci) and D-loop sequences of mitochondrial DNA and comparing with reference data from other breeds or genetic lines. The results indicate that Ecuadorian Creole chickens are the result of the admixture of different genetic groups that occurred during the last five centuries. While the influence of South Spanish breeds is demonstrated in the colonial age, genetic relationships with other breeds (Leghorn, Spanish fighter cock) cannot be discarded. The geographical configuration of the country and extreme climate variability have influenced the genetic isolation of groups constituting a homogeneous genetic status into the whole population. This is not only a source of genetic variation, but also a critical point because genetic drift produces a loss of genetic variants.
