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Most heavy metal ions are known to be toxic and carcinogenic when present in high amounts. Thus, rapid and reliable on-site detection of these ions is crucial. Voltammetry is a highly sensitive electrochemical method that has been...
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Most heavy metal ions are known to be toxic and carcinogenic when present in high amounts. Thus, rapid and reliable on-site detection of these ions is crucial. Voltammetry is a highly sensitive electrochemical method that has been widely used for heavy metal detection offering the advantages of sensitivity and rapidity. On the other hand, nanoparticles offer the advantages of high surface area and high selectivity. Thus, this review aims to highlight the application of metallic and metallic oxide nanoparticles for the voltammetric detection of heavy metals. The nanoparticles used were either applied solely on the electrode or as modifiers with various materials. In all cases, the synthesized devices showed an enhanced analytical performance, such that the limits of detection were lowered and the sensitivities were increased as compared to voltammetric systems not using nanoparticles. Moreover, the applicability of some of these systems was investigated in real samples. (C) 2020 Elsevier B.V. All rights reserved.
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Global pandemic COVID-19 has affected almost the entire world population in every aspect of life in terms of health, environment, and economy. According to WHO, the main source of transmission of this deadly virus (SARS-CoV-2) is ...
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Global pandemic COVID-19 has affected almost the entire world population in every aspect of life in terms of health, environment, and economy. According to WHO, the main source of transmission of this deadly virus (SARS-CoV-2) is proven to be through the aerosol coming from the infected person's cough, sneeze, or exhalation. These aerosols are likely to settle down on the exposed surfaces and such infected surfaces are known to be potential source of contamination. The spread of the viral infections can be controlled in a great extent with the development of anti-viral nano-coating materials for various surfaces. Thus, development of such anti-viral nano-coating materials becomes increasingly popular amongst the researchers due to their extensive applications on surfaces, such as, glass, cotton, plastic and many more. In this short review, we will describe a summary of the popular metals and metal oxide nanomaterials commonly explored as antiviral coatings to control the spread of various viral disease along with the corresponding working principle and effectivity of such coatings.
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Nanotechnology is poised to have a huge impact on food packaging applications. Bimetallic and trimetallic nanoparticles (NPs) are formed by combining two and three different metals and metal oxides, respectively. Compared with mon...
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Nanotechnology is poised to have a huge impact on food packaging applications. Bimetallic and trimetallic nanoparticles (NPs) are formed by combining two and three different metals and metal oxides, respectively. Compared with monometallic NPs, bimetallic and trimetallic NPs have attracted immense attention because of their diverse shape, size, high surface-to-volume ratios, chemical/physical stability, activity, and greater degree of selectivity, with respect to both technological and scientific view. Metal and metal oxide NPs proved to be highly potent antimicrobial and antioxidant properties, together with nanobiosensors for tracing and monitoring the condition of food. These nanostructured materials embedded with both biodegradable and non-degradable polymer to increase mechanical strength and barrier properties to extend the shelf life of various foods. In addition, polymer nanocomposites are treated with essential oils (EOs) to improve their performance in food packaging. In this review, we summarized most recent innovations in food packaging, merits, and demerits of biodegradable and non-degradable polymer used for food packaging. It also provides the different synthetic methods, importance of bimetallic and trimetallic NPs in relation to food packaging to enhance the shelf life of food. Finally, mode of action, toxicity, regulation, and legislation for safety in human consumption and the environment are also discussed.
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The production and demand of nanoparticles in the manufacturing sector and personal care products, release a large number of engineered nanoparticles (ENPs) into the atmosphere, aquatic ecosystems, and terrestrial environments. Th...
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The production and demand of nanoparticles in the manufacturing sector and personal care products, release a large number of engineered nanoparticles (ENPs) into the atmosphere, aquatic ecosystems, and terrestrial environments. The intentional or involuntary incorporation of ENPs into the environment is carried out through different processes. The ENPs are combined with other compounds and release into the atmosphere, settling on the ground due to the water cycle or other atmospheric phenomena. In the case of aquatic ecosystems, the ENPs undergo hetero-aggregation and sedimentation, reaching different living organisms and flora, as well as groundwater. Accordingly, the high mobility of ENPs in diverse ecosystems is strongly related to physical, chemical, and biological processes. Recent studies have been focused on the toxicological effects of a wide variety of ENPs using different validated biological models. This literature review emphasizes the study of toxicological effects related to using the most common ENPs, specifically metal and metal/oxides-based nanoparticles, addressing different synthesis methodologies, applications, and toxicological evaluations. The results suggest negative impacts on biological models, such as oxidative stress, metabolic and locomotive toxicity, DNA replication dysfunction, and bioaccumulation. Finally, it was consulted the protocols for the control of risks, following the assessment and management process, as well as the classification system for technological alternatives and risk management measures of ENPs, which are useful for the transfer of technology and nanoparticles commercialization.
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Immobilized nanosized metal (oxides) on carbonaceous carriers were prepared by hydrolysis under mild conditions by using the carrier pores as a kind of nanoreactor. Metal alkoxide vapor was adsorbed on the carrier and then formed ...
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Immobilized nanosized metal (oxides) on carbonaceous carriers were prepared by hydrolysis under mild conditions by using the carrier pores as a kind of nanoreactor. Metal alkoxide vapor was adsorbed on the carrier and then formed the product upon exposure to water vapor. With this facile method, Titania, Vanadia, Rhodium (oxide), and Platinum (oxide) nanostructures were prepared at high yields, high loadings, and good dispersion in the carrier material. High number concentrations of spheroidal nanoparticles of uniform size (diameter ca. 5 nm) were obtained from less reactive precursors, whereas with highly reactive precursors, such nanoparticles occurred only after subsequent calcination. Nanoparticles appeared to be the thermodynamically stable form of the metal (oxide) produced in the pores. Highly reactive precursors formed metastable seeds, which nucleated and restructured into nanoparticles upon subsequent exposure to heat. The presented method allows for preparation of metal (oxide) nanostructures and effective control of their size and shape.
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Immobilized nanosized metal (oxides) on carbonaceous carriers were prepared by hydrolysis under mild conditions by using the carrier pores as a kind of nanoreactor. Metal alkoxide vapor was adsorbed on the carrier and then formed ...
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Immobilized nanosized metal (oxides) on carbonaceous carriers were prepared by hydrolysis under mild conditions by using the carrier pores as a kind of nanoreactor. Metal alkoxide vapor was adsorbed on the carrier and then formed the product upon exposure to water vapor. With this facile method, Titania, Vanadia, Rhodium (oxide), and Platinum (oxide) nanostructures were prepared at high yields, high loadings, and good dispersion in the carrier material. High number concentrations of spheroidal nanoparticles of uniform size (diameter ca. 5 nm) were obtained from less reactive precursors, whereas with highly reactive precursors, such nanoparticles occurred only after subsequent calcination. Nanoparticles appeared to be the thermodynamically stable form of the metal (oxide) produced in the pores. Highly reactive precursors formed metastable seeds, which nucleated and restructured into nanoparticles upon subsequent exposure to heat. The presented method allows for preparation of metal (oxide) nanostructures and effective control of their size and shape.
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This study demonstrates that the precursor reduction kinetics can be employed to control the morphology and composition of bimetallic metal/metal oxides systems obtained by galvanic replacement reaction using metal oxides as sacri...
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This study demonstrates that the precursor reduction kinetics can be employed to control the morphology and composition of bimetallic metal/metal oxides systems obtained by galvanic replacement reaction using metal oxides as sacrificial templates. This work investigated Cu2O as a proof-of-concept example, in which the relative rates of Cu2O oxidation by O-2 and by noble metal precursors determined the morphology and composition of the products. We focused on three metal precursors with fast, medium, and slow reduction kinetics in the presence of Cu2O under aerobic conditions: PdCl42-, AuCl4-, and Ru-3(+), respectively. It was found that metal-oxide-based bowls, rattles, or dendrites can be obtained by simply changing the precursor reduction kinetics. These results provide novel insights over the versatility and mechanistic understanding of galvanic replacement to the synthesis of metal/metaloxide bimetallic nanoparticles.
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Background: The concept of nutraceuticals has gained increased attention recently as it is based on using natural substances for therapeutic applications. However, limitations such as low bioavailability have restricted the use of...
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Background: The concept of nutraceuticals has gained increased attention recently as it is based on using natural substances for therapeutic applications. However, limitations such as low bioavailability have restricted the use of these substances thus far. Nanoencapsulation of nutraceuticals has been proposed as a promising solution to circumvent such issues by increasing their bioavailability and targeting their release. Metal and metal oxide nanoparticles are amongst the inorganic nanocarriers that have been studied for their ability to encapsulate nutraceuticals. Objectives'. The aim of this article is to provide an overview of metal and metal oxide nanoparticles and their synthesis and applications. Furthermore, the conjugation of these nanoparticles with nutraceuticals will be discussed, along with their potential applications. Conclusion: It has been observed that the conjugation of nutraceuticals with metal nanoparticles resulted in the cumulative properties of both these factors with increased effectiveness. Such advancements are crucial for nutraceutical use in important theranostic applications that combine diagnosis and therapy.
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Many organic synthesis systems use thermal catalysis to achieve higher product efficiency, and it is of interest to drive reactions by light irradiation at moderate reaction conditions. Other than semiconductors, recent reports ha...
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Many organic synthesis systems use thermal catalysis to achieve higher product efficiency, and it is of interest to drive reactions by light irradiation at moderate reaction conditions. Other than semiconductors, recent reports have shown that metal nanostructures can be used as direct photocatalysts to drive chemical reactions. In this review, we summarize recent progress in direct photocatalysis in organic synthesis using plasmonic and non-plasmonic metal nanostructures. It starts with a comprehensive introduction to surface plasmons and the role of interband transitions in non-plasmonic metal nanostructures. The application of metal nanostructures in organic synthesis is systematically reviewed, followed by the reaction mechanisms; the role of light-excited energetic electrons, enhanced electromagnetic fields and the photothermal effect are detailed. The influence of light intensity and wavelength is discussed, as well as the critical parameters of photocatalyst design. Finally, the outlook and future opportunities of this new exciting field will be discussed.
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The present mini-review describes the use of glycerol as solvent for the synthesis of metal and metal oxide nanoparticles exhibiting catalytic properties. This contribution specially underlines the ability of glycerol to both disp...
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The present mini-review describes the use of glycerol as solvent for the synthesis of metal and metal oxide nanoparticles exhibiting catalytic properties. This contribution specially underlines the ability of glycerol to both disperse and immobilize metal-based nanoparticles, increasing their lifetime. In other words, glycerol can act as a liquid support for nanocatalysts.
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