The review is devoted to the analysis of publications on the synthesis and chemical modification of the surface of silver and gold nanoparticles and their use in chemical and biochemical analysis by ...spectrometry. The formation and subsequent modification of the chemical composition of the surface layer of nanoparticles ensures the solution of problems of the group and individual determination of analytes, i.e., metal ions and organic and bioorganic compounds. The presence of an accessible well-developed surface bearing functional groups of different nature in combination with the effects of surface plasmon resonance and enhanced and surface-enhanced Raman scattering opens wide prospects for the application of nanoparticles to chemical and biochemical analysis.
Contemporary nonenzymatic methods for the qualitative and quantitative determination of hydrogen peroxide and reactive oxygen species, preceding to hydrogen peroxide or resulting from it, are ...reviewed. Many of these procedures can be applied to the detection and determination of reactive oxygen species, for example, anions, peroxide radical anions, hydroxide radicals, etc., in both model and real samples that are of practical importance in biochemistry and medicine. The main direction of development in this area includes the target formation of a surface layer of a sensing element at the nanoscale level, including using nanoparticles. In some cases, higher selectivity can be achieved, and the analytical and performance characteristics of the procedures, such as minimum detectable concentration, analytical range, or sensitivity, can be improved. Most of the cited papers were published after 2010.
The main scientific problems solved within the “Development of controlled fusion technologies and innovative plasma technologies” federal project, part of the comprehensive program “Development of ...equipment, technologies, and scientific research in the field of atomic energy use in the Russian Federation for the period up to 2024” are described. A brief history of development of the project is given, and the description of its main components, participants, anticipated results, and possibilities for the future is p-resented. This paper is a foreword to the materials of the journal issue entirely devoted to the Tokamak with Reactor Technologies (TRT) project, which is to be developed within the federal project.
The interaction of Ag
+
ions existing on the surface of silver nanoparticles with complexing agents, such as ammonia, ammonium thiocyanate, and sodium thiosulfate, has been studied. Both the presence ...of complexing agents in the initial reaction mixture and their introduction into preliminarily synthesized sols of silver nanoparticles lead to a small shift of the absorption maximum toward long wavelengths and its considerable broadening. In both cases, there is a correlation of the absorption band width with the logarithm of formation constants of corresponding silver complexes. This can be evidence of analogous chemical processes that occur on the surface of nanoparticles. The surface complexation is of interest both for a fundamental understanding of the interaction nature and in the applied aspect for the determination of complexing agents in aqueous systems.
This review deals with one of the most important classes of nanomaterials — oxide nanoparticles. Preparative methods for the synthesis of nanooxides, their hydro- and organosols, and methods for the ...chemical surface modification of oxide nanoparticles are comprehensively reviewed. The high surface area of nanooxide particles and their relatively low porosity allows efficient modification of the surface to obtain highly selective sorbents, microheterogeneous catalysts, biocompatible magnetic and fluorescent labels, means of drug delivery or removal of harmful components from living systems, and objects of environmental monitoring.
Sols of silver nanoparticles surface-stabilized by cetyltrimethylammonium bromide or polyvinylpyrrolidone can be used for the determination of active chlorine in water samples. As analytes modeling ...active chlorine in water, we used freshly prepared sodium hypochlorite solutions. Because of the high values of standard electrode potentials of reduction half-reactions, active forms of chlorine can oxidize silver nanoparticles, exhibiting the effect of surface plazmon resonance with an absorption maximum near 400 nm. The absorption intensity of silver nanoparticles correlates with the concentration of sodium hypochlorite. This effect was used for the qualitative and quantitative determination of active chlorine in water samples. The quantitative characteristics of the described method were obtained for two versions of analysis, spectrophotometry and photometric titration. The calibration graphs for both versions were similar and linear in the range of sodium hypochlorite concentrations 0.1–2.5 mM.
Studies performed over the last decade in the field of selective catalytic oxidation of primary and secondary alcohols to corresponding carbonyl compounds have been surveyed. Works on catalysts based ...on free metals and metal complexes have been considered. Special attention is given to the oxidation reactions of alcohols with air or molecular oxygen. The effect of the nature of the alcohol, oxidizing agent, catalyst, and solvent on the rate of the oxidation reaction and its selectivity is discussed.
Papers dealing with chemical modification of the surface of noble metal nanoparticles and their use in analytical and bioanalytical chemistry, pharmacology, etc., are analyzed. Grafting of a layer of ...preset chemical composition on the nanoparticle surface allows preparation of functional materials combining the properties of the metal core (surface plasmon resonance, enhancement of fluorescence and nonelastic scattering) and shell (selective interaction with components of the surrounding medium). Combination of these properties opens wide prospects for using the modified nanoparticles in various branches of science and engineering, primary in chemical and biochemical analysis, and also in pharmacology.
The results of studies on the chemical synthesis and biosynthesis of metal nanoparticles in condensed media published after 2000 are analyzed and described systematically. The growth and ...transformations of the metallic core of nanoparticles as well as the composition and structure of the surface layer are considered and their effects on the nanoparticle size and shape are analyzed.
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