Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


nanoparticles

Gold nanostars as a photoagent under the antimicrobial action of infrared (808 nm) laser radiation

Gold nanostars with an average core diameter of 122,2 nm and a spike length of 114,6 nm were synthesized and characterized at a concentration of 5,36×1010 pcs/ml with an absorption maximum of 840 nm. Gold nanostars were coated with thiolated polyethylene glycol, its amount was about 8×104 molecules per 1 particle and about 4,4×1015 molecules/ml in the colloid. The zeta potential of gold nanostars coated with PEG-SH was −2.3 mV.

The Influence of Aqueous Dispersions of Metal Nanoparticles on the Adhesive Properties of the Standard and Clinical Strains of Staphylococcus aureus

The initial stage of interaction of infectious agents with micro-organisms cells is the process of adhesion. So there is a need to develop methods that reduce the adhesive activity of microorganisms. Aim: to study the impact of water and water dialyzed dispersion of silver and copper nanoparticles obtained by biochemical synthesis, on the adhesive properties of the standard and clinical strains of S. aureus. Using standard techniques for cells of S.

The Study of Antibacterial Properties of Coatins Based on Metal (Ag, Zn) Nanoparticles in Silicon Dioxide Matrix

The influence of coatings on the basis of Ag and Zn metal nanoparticles in a silica matrix in combination with ultraviolet (365 nm) radiation on Staphylococcus aureus 209 P bacteria was studied. It was shown that the investigated coatings without access to light inhibit the growth of microorganisms by 45% after 3 hours of incubation and 55–70% after 5 hours of incubation. Enhancement of antibacterial properties of nanocoatings was achieved by exposure to UV (365 nm) radiation.

Express Method for Cefazolin Determination in Small Samples Sensors Planar Potentiometric

The unmodified and modified by polyaniline and nanoparticles planar potentiometric sensors on the basis of tetradecylammonium associates with a complex silver (I) – cefazolin are created. Optimum ratios of components in carbon-containing ink are established: 30–32% carbon powder, 16–18% polyvinylchloride, 48–50% dibutylphthalate and 1–3% of electrode active compound (EAC). Planar sensors of two types are examined: electrode active compounds, electrode active compound and modifiers were added into in carbon-сontaining ink.

Antimicrobial Photodynamic Effects Using Coatings Based on Metal Nanoparticles (Ag, Au)

The combined effect of coatings based on nanoparticles of metals Ag, Au, ultraviolet (365 nm, UVR) and infrared (808 nm, IRR) radiation on Staphylococcus aureus 209 P was studied. Decrease in numbers was shown by 2% in the case of silver coatings and by 8% in the case of gold coatings after 1 h incubation. However, exposure of the IRR to bacterial suspensions caused the death of 43% of the population after 5 min, 86% of the population after 30 min.

Total Charge of Chitosan and Chitosan Succinyl Macromolecules Effect on the Stability of Particles of Silver Iodide Sols in Polymer-Colloidal Based Dispersions

Obtaining stable polymer-colloidal dispersions based on watersoluble polymers and inorganic colloidal particles, such as silver iodide sol, followed by removal of the dispersion medium is one of the ways to create hybrid biomedical materials (e.g. films, threedimensional matrices). The current work is devoted to studying the possibility of increasing the stability of polymer-colloidal systems based on silver iodide sols, succinyl chitosan and chitosan polysaccharides by reducing the total charge of macromolecules.

Modified Potentiometric Sensors of Various Types for Ceftriaxone Determination

The planar unmodified and modified by polyaniline, nanoparticles and their binary mixtures potentiometric sensors of various types were manufactured on the basis of tetradecylammonium associates (TDA) with complex connections silver (I) – ceftriaxone (Ag (I) – Ceftr). In sensors of I type electroactive components (EAC) and modifiers were brought in carboniferous ink. The polyvinylchloride plasticized unmodified and modified membranes on the basis [Ag2 (Ceftr)2] 2- · 2TDA were used in the sensors of II type; C (EAC) = 1,2,3%.

New Gypsum-Titanium Composites for Antimicrobial Photocatalytic Action on Staphylococcus aureus

The last decade has allowed the creation of new composite photocatalytic materials with a wide range of applications. Antimicrobial coatings based on photocatalytic materials are environmentally friendly and effective for use in health care, the food industry, enterprises and service facilities. This study is devoted to the study of the antibacterial activity of gypsum-titanium nanocomposites.

Chromatographical Analysis of Meldonium with Preliminary Concentration by Solid-Phase Extraction on Magnetite Nanoparticles

A comprehensive method for meldonium analysis, based on a combination of magnetic solid-phase concentration of the analyte on magnetite nanoparticles modified with cetylammonium bromide (CTAB) cations and its subsequent analysis by thin-layer chromatography (TLC) were developed in the process of study. The influence of a number of factors on meldonium sorption was studied, namely: pH, sorbent mass, sorption and mixing times; optimal extraction conditions were determined.

Photocatalytic effect of led radiation (405 nm) and new Al2O3 3D-nanocomposites on the growth of Staphylococcus aureus

The progressive growth of bacterial resistance to antibiotic drugs requires the creation of highly efficient nanomaterials. Aluminum oxide is a stable non-toxic semiconductor material; however, the photocatalytic properties of its modifications in relation to microorganisms are not well understood. In this study, we used new 3D composites of aluminum oxyhydroxide (Al2O3 ? nH2O) in three modifications (?, ? and ?), which are a mesh of 150 nm nanofibrils.

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