Removal of indigo carmine by a Ni nanoscale oxides/Schoenoplectus acutus composite in batch and fixed bed column systems

Removal behavior of indigo carmine by Schoenoplectus acutus and Ni nanoscale oxides/Schoenoplectus acutus composite was determined. The characterization of both materials was done by TEM, SEM/EDS, DRX, and BET. Experimental data were best fitted to pseudo second order and Langmuir-Freundlich models for kinetics and isotherm, respectively; these results indicate a chemisorption mechanism on heterogeneous materials. Adsorption capacity of Ni nanoscale oxides/Schoenoplectus acutus composite was high in comparison with other adsorbents (760 mg/g). Adsorption of dye is not affected by pH (3 to 9). Metal nanoparticles supported on cheap and eco-friendly adsorbents are an alternative for the removal of dyes from wastewater

Plasmonic and fluorescent sensors of metal ions in water based on biogenic gold nanoparticles

SE REPORTA LA CARACTERIZACION DE NANOPARTICULAS PLASMONICASGold nanoparticles (AuNPs) were synthesized using a rapid, single step, and completely green biosynthetic method employing aqueous Citrus paradisi (grapefruit) extract, which was used as both the reducing and capping agent. Au(III) ions were rapidly reduced by the aqueous grapefruit extract, leading to the formation of highly stable and crystalline colloidal AuNPs, confirmed by the surface plasmon resonance (SPR) peak centered at 544 nm in the UV–Vis spectra. Biogenic AuNPs have been evaluated as plasmonic, fluorescent and naked-eye sensors of Pb2+, Ca2+, Hg2+, Zn2+ and Cu2+ ions in aqueous media, with a good performance and selectivity. Of the three methods used for metal ions sensing, fluorescent sensors shows better results, specifically with Ca2+, Cu2+ and Pb2+. Copper was detected by both plasmonic and fluorescent methods

Plasmonic Sensing of Aqueous-Divalent Metal Ions by Biogenic Gold Nanoparticles

Research Article Plasmonic Sensing of Aqueous-Divalent Metal Ions by Biogenic Gold NanoparticlesThe chemical interaction between biogenic gold nanoparticles (AuNPs) and several metal (II) ions can be regarded as a practical, twofold, colorimetric, and plasmon resonance sensing method for the recognition of some divalent metal ions in aqueous solutions. The green synthesized AuNPs, using Camellia sinensis as a reducing agent, were characterized by a surface plasmon resonance (SPR) using UV-Vis spectroscopy, infrared spectroscopy, and transmission electron microscopy. The AuNP colloidal solutions obtained have a pink-reddish color with SPRs centered between 529 and 536 nm. AuNPs with spherical, triangular, and hexagonal shapes were found by TEM analyses. Despite their divergent morphologies, these AuNPs can be employed as colorimetric and plasmon resonance sensors for detection of Ca2+, Sr2+, Cu2+, and Zn2+, primarily, in aqueous solutions. Sensibility studies based on molar concentrations were also performed for these metal ions. Furthermore, solid biogenic AuNPs/cellulosic biocomposites were prepared with the aim of developing portable, fast, and dependable colorimetric sensors; nevertheless, these biocomposites resulted to be good adsorbent materials of metal ions

síntesis, caracterización y aplicaciones

La Nanotecnología es un área de la ciencia relativamente nueva. No obstante, una gran parte de la comunidad científica considera que es la base del desarrollo tecnológico de los próximos años. Dentro del campo de estu dio de la nanotecnología encontramos las nanoestructuras metálicas. Estos nanomateriales presentan propiedades muy interesantes y diferentes a los materiales “en bulto” o a escala macroscópica; entre ellas, la conductividad eléctrica y las propiedades magnéticas, ópticas y de catálisis, propiedades que las hacen candidatas a innumerables aplicaciones en todos los campos de la tecnología. Desafortunadamente, como suele suceder en muchos ámbitos de la ciencia y la tecnología, es la comunidad científica que estudia un área concreta quien conoce en exclusiva esa información. Por ello, nuestro grupo de investigación ha escrito este libro intentando cum Nanoestructuras metálicas: síntesis, caracterización y aplicaciones viii plir dos objetivos principales: el primero, dar a conocer los últimos resultados de nuestras investigaciones con nanoestructuras metálicas y algunas de sus aplicaciones, dicha información va dirigida a la comunidad científica interesada en el área; el segundo objetivo es redactar un libro que sea útil para quienes estén interesados en esta ciencia aunque no tengan demasiada experiencia en el tema, para ello, cada capítulo cuenta con una parte introductoria en la que se presentan aspectos generales del tema que se trata. A su vez, se ha intentado emplear un lenguaje de fácil comprensión pero sin que se pierda la especificidad de cada tema. Finalmente, los autores de este libro queremos agradecer a nuestra alma mater, la Universidad Autónoma del Estado de México, por el apoyo recibido para la publicación del mismo, esperando poder contribuir así al fortalecimiento del área científica.El desarrollo de la tecnología siempre ha estado íntimamente relacionado con las necesidades del ser humano por controlar su entorno y los fenómenos naturales, esto con el objeto de lograr una mejor calidad de vida para las personas. Muchos de los descubrimientos científicos más importantes, como es el caso de las leyes de Newton o la teoría de la relatividad de Einstein, revolucionaron la tecnología dando paso a una nueva era, en la que todo se explica desde el principio fundamental de los átomos. Ello provocó que científicos como Richard Feyman, ganador del Premio Nobel de Física en 1965, empezaran a vislumbrar las posibilidades que presentaba la nanotecnología. Feyman mencionó que, al poder estudiar y entender el comportamiento de los átomos y las moléculas, se podrían interpretar de mejor manera los fenómenos en el universo, dando paso a la frase: “En el fondo hay espacio de sobra”

Removal of indigo carmine by a Ni nanoscale oxides/Schoenoplectus acutus composite in batch and fixed bed column systems

Removal behavior of indigo carmine by Schoenoplectus acutus and Ni nanoscale oxides/Schoenoplectus acutus composite was determined. The characterization of both materials was done by TEM, SEM/EDS, DRX, and BET. Experimental data were best fitted to pseudo second order and Langmuir-Freundlich models for kinetics and isotherm, respectively; these results indicate a chemisorption mechanism on heterogeneous materials. Adsorption capacity of Ni nanoscale oxides/Schoenoplectus acutus composite was high in comparison with other adsorbents (760 mg/g). Adsorption of dye is not affected by pH (3 to 9). Metal nanoparticles supported on cheap and eco-friendly adsorbents are an alternative for the removal of dyes from wastewater

nanoestructuras metálicas

La Nanotecnología es un área de la ciencia relativamente nueva. No obstante, una gran parte de la comunidad científica considera que es la base del desarrollo tecnológico de los próximos años. Dentro del campo de estu dio de la nanotecnología encontramos las nanoestructuras metálicas. Estos nanomateriales presentan propiedades muy interesantes y diferentes a los materiales “en bulto” o a escala macroscópica; entre ellas, la conductividad eléctrica y las propiedades magnéticas, ópticas y de catálisis, propiedades que las hacen candidatas a innumerables aplicaciones en todos los campos de la tecnología. Desafortunadamente, como suele suceder en muchos ámbitos de la ciencia y la tecnología, es la comunidad científica que estudia un área concreta quien conoce en exclusiva esa información. Por ello, nuestro grupo de investigación ha escrito este libro intentando cum Nanoestructuras metálicas: síntesis, caracterización y aplicaciones viii plir dos objetivos principales: el primero, dar a conocer los últimos resultados de nuestras investigaciones con nanoestructuras metálicas y algunas de sus aplicaciones, dicha información va dirigida a la comunidad científica interesada en el área; el segundo objetivo es redactar un libro que sea útil para quienes estén interesados en esta ciencia aunque no tengan demasiada experiencia en el tema, para ello, cada capítulo cuenta con una parte introductoria en la que se presentan aspectos generales del tema que se trata. A su vez, se ha intentado emplear un lenguaje de fácil comprensión pero sin que se pierda la especificidad de cada tema. Finalmente, los autores de este libro queremos agradecer a nuestra alma mater, la Universidad Autónoma del Estado de México, por el apoyo recibido para la publicación del mismo, esperando poder contribuir así al fortalecimiento del área científica.El desarrollo de la tecnología siempre ha estado íntimamente relacionado con las necesidades del ser humano por controlar su entorno y los fenómenos naturales, esto con el objeto de lograr una mejor calidad de vida para las personas. Muchos de los descubrimientos científicos más importantes, como es el caso de las leyes de Newton o la teoría de la relatividad de Einstein, revolucionaron la tecnología dando paso a una nueva era, en la que todo se explica desde el principio fundamental de los átomos. Ello provocó que científicos como Richard Feyman, ganador del Premio Nobel de Física en 1965, empezaran a vislumbrar las posibilidades que presentaba la nanotecnología. Feyman mencionó que, al poder estudiar y entender el comportamiento de los átomos y las moléculas, se podrían interpretar de mejor manera los fenómenos en el universo, dando paso a la frase: “En el fondo hay espacio de sobra”

Plasmonic Sensing of Aqueous-Divalent Metal Ions by Biogenic Gold Nanoparticles

Research Article Plasmonic Sensing of Aqueous-Divalent Metal Ions by Biogenic Gold NanoparticlesThe chemical interaction between biogenic gold nanoparticles (AuNPs) and several metal (II) ions can be regarded as a practical, twofold, colorimetric, and plasmon resonance sensing method for the recognition of some divalent metal ions in aqueous solutions. The green synthesized AuNPs, using Camellia sinensis as a reducing agent, were characterized by a surface plasmon resonance (SPR) using UV-Vis spectroscopy, infrared spectroscopy, and transmission electron microscopy. The AuNP colloidal solutions obtained have a pink-reddish color with SPRs centered between 529 and 536 nm. AuNPs with spherical, triangular, and hexagonal shapes were found by TEM analyses. Despite their divergent morphologies, these AuNPs can be employed as colorimetric and plasmon resonance sensors for detection of Ca2+, Sr2+, Cu2+, and Zn2+, primarily, in aqueous solutions. Sensibility studies based on molar concentrations were also performed for these metal ions. Furthermore, solid biogenic AuNPs/cellulosic biocomposites were prepared with the aim of developing portable, fast, and dependable colorimetric sensors; nevertheless, these biocomposites resulted to be good adsorbent materials of metal ions

Cerium Biomagnification in a Terrestrial Food Chain: Influence of Particle Size and Growth Stage

Mass-flow modeling of engineered nanomaterials (ENMs) indicates that a major fraction of released particles partition into soils and sediments. This has aggravated the risk of contaminating agricultural fields, potentially threatening associated food webs. To assess possible ENM trophic transfer, cerium accumulation from cerium oxide nanoparticles (nano-CeO₂) and their bulk equivalent (bulk-CeO₂) was investigated in producers and consumers from a terrestrial food chain. Kidney bean plants (Phaseolus vulgaris var. red hawk) grown in soil contaminated with 1000–2000 mg/kg nano-CeO₂ or 1000 mg/kg bulk-CeO₂ were presented to Mexican bean beetles (Epilachna varivestis), which were then consumed by spined soldier bugs (Podisus maculiventris). Cerium accumulation in plant and insects was independent of particle size. After 36 days of exposure to 1000 mg/kg nano- and bulk-CeO₂, roots accumulated 26 and 19 μg/g Ce, respectively, and translocated 1.02 and 1.3 μg/g Ce, respectively, to shoots. The beetle larvae feeding on nano-CeO₂ exposed leaves accumulated low levels of Ce since ∼98% of Ce was excreted in contrast to bulk<i>-</i>CeO₂. However, in nano-CeO₂ exposed adults, Ce in tissues was higher than Ce excreted. Additionally, Ce content in tissues was biomagnified by a factor of 5.3 from the plants to adult beetles and further to bugs

Environmental Effects of Nanoceria on Seed Production of Common Bean (<i>Phaseolus vulgaris</i>): A Proteomic Analysis

The rapidly growing literature on the response of edible plants to nanoceria has provided evidence of its uptake and bioaccumulation, which delineates a possible route of entry into the food chain. However, little is known about how the residing organic matter in soil may affect the bioavailability and resulting impacts of nanoceria on plants. Here, we examined the effect of nanoceria exposure (62.5–500 mg/kg) on kidney bean (<i>Phaseolus vulgaris</i>) productivity and seed quality as a function of soil organic matter content. Cerium accumulation in the seeds produced from plants in organic matter enriched soil showed a dose-dependent increase, unlike in low organic matter soil treatments. Seeds obtained upon nanoceria exposure in soils with higher organic matter were more susceptible to changes in nutrient quality. A quantitative proteomic analysis of the seeds produced upon nanoceria exposure provided evidence for upregulation of stress-related proteins at 62.5 and 125 mg/kg nanoceria treatments. Although the plants did not exhibit overt toxicity, the major seed proteins primarily associated with nutrient storage (phaseolin) and carbohydrate metabolism (lectins) were significantly down-regulated in a dose dependent manner upon nanoceria exposure. This study thus suggests that nanoceria exposures may negatively affect the nutritional quality of kidney beans at the cellular and molecular level. More confirmatory studies with nanoceria along different species using alternative and orthogonal “omic” tools are currently under active investigation, which will enable the identification of biomarkers of exposure and susceptibility