The Role of Nanoanalytics in the Development of Organic-Inorganic Nanohybrids—Seeing Nanomaterials as They Are

The functional properties of organic-inorganic (O-I) hybrids can be easily tuned by combining system components and parameters, making this class of novel nanomaterials a crucial element in various application fields. Unfortunately, the manufacturing of organic-inorganic nanohybrids still suffers from mechanical instability and insufficient synthesis reproducibility. The control of the composition and structure of nanosurfaces themselves is a specific analytical challenge and plays an important role in the future reproducibility of hybrid nanomaterials surface properties and response. Therefore, appropriate and sufficient analytical methodologies and technical guidance for control of their synthesis, characterization and standardization of the final product quality at the nanoscale level should be established. In this review, we summarize and compare the analytical merit of the modern analytical methods, viz. Fourier transform infrared spectroscopy (FTIR), RAMAN spectroscopy, surface plasmon resonance (SPR) and several mass spectrometry (MS)-based techniques, that is, inductively coupled plasma mass spectrometry (ICP-MS), single particle ICP-MS (sp-ICP-MS), laser ablation coupled ICP-MS (LA-ICP-MS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), liquid chromatography mass spectrometry (LC-MS) utilized for characterization of O-I nanohybrids. Special attention is given to laser desorption ionization mass spectrometry (LDI-MS) as a reliable nanoanalytical platform for characterization of O-I hybrid nanomaterials, their quality, design verification and validation

Crossfit in the introduction of the All-Russian sports complex TRP

In this article it is spoken about instilling love for a healthy lifestyle, peculiarities of implementation of crossfit and its benefitsВ данной статье говорится о привитии любви к здоровому образу жизни, об особенностях внедрения кроссфита и его польз

Patterns of Bioelectrical Brain Activity of Stroke Patients after Using Neurofeedback in the Rehabilitation Process

Background: Stroke patients develop the ability to perform higher levels of functional activity on basis of concentrated rehabilitative training which affects sensory, motor and cognitive functions. Objective: The main aim of our work was to show the usefullness of neurofeedback therapy in rehabilitation of stroke patients. Design: 27 stroke patients with severe disabilitis were included in the pilot study (men aged 32 to 68 years, mean age 52.4 ± 3.29 years, median 57 years). They all underwent complex study of brain bioelectrical activity EEG and 15 trainings of neurofeedback. Results: By the end of the rehabilitation (after 17 sessions) recollection of psychotrauma led to an increase in the power of the alpha rhythm in both left and right hemispheres. Atthe endpoint of the study differences in the power of the alpha rhythm in the left hemisphere were 1.47 times greater, and in the right hemisphere, 1.95 times greater than at the first visit. The regress of theta rhythm (1.25 times in the left, 1.11 times in the right hemisphere) decreased considerable, which affected the alpha / thetaratio - decreased 1.04 times in the left, 1.18 times in the right hemisphere, and also the coefficient (alpha + theta) / beta - decreased 1.17 times in the left and 1.21 times in the right. Differences in the saturation of blood vessels index at the last visit were 1.69 times greater than at the first visit. Neurophysiological changes correlated with an improvement in the emotional shpere. By the time of discharge, the indicators on the Beck depression scale decreased by 1.4 times, on the Spielberger-Khanin scale, situational anxiety decreased by 1.63 times, personal anxiety - by 1.4 times; regression of indicators in the hospital scale of anxiety and depression (HADS) was observed in 1.89 times. Conclusion: The data presented indicate that the use of the neurofeedbackmethod leads to a reduction of anxiety-depressive disorders, which positively affects the usefulness of combine rehabilitation. Keywords: stroke, neurofeedback, electroencephalogram, alpha rhythm, rehabilitation

In situ modulation of enzyme activity via heterogeneous catalysis utilizing solid electroplated cofactors

During product isolation the received bioreceptors often do not exhibit a sufficient biochemical activity due to multistep dissociation and loss of cofactors. However, for bioelectrochemical applications the presence of cofactors is necessary for a successful oxidative or reductive conversion of the substrates to the products. Herein, we show how the immobilization of the required electroplated cofactors in a design of amperometric electrodes can in situ assist the activity of apo-enzymes. Compared to conventional approaches used in enzyme engineering this tailored nanoengineering methodology is superior from economic point of view, labor and time costs, storage conditions, reduced amount of waste and can fill the gap in the development of tuned bioelectrocatalysts

A tandem of GC-MS and electroanalysis for a rapid chemical profiling of bacterial extracellular matrix

Herein an assay toward a rapid and reliable profiling of extracellular matrix of Escherichia coli (E. coli) utilizing a tandem of GC-MS as a tool for definition of the exact chemical nature of low molecular weight compounds and cyclic voltammetry for their high throughput detection is presented. Briefly, during a set of investigations the formation of glycerol in the extracellular matrix (ECM) of E. coli at physiological relevant conditions of cells was revealed. Based on the obtained knowledge, the electrochemical protocol allowing both qualitative and quantitative analyses of glycerol in E. coli ECMs at palladium ink-modified screen printed electrodes with precision values (RSD) <10 % and recovery rates ranged from 98 % to 102 % was proposed. The provided protocol for a rapid electrochemical profiling of the bacterial ECMs can readily be used as a guideline for the controlled electroanalysis of target electroactive signaling analytes in complex biological samples

Towards hybrid one-pot/one-electrode Pd-NPs-based nanoreactors for modular biocatalysis

Here, fundamental aspects affecting template-assisted engineering of oxidase-associated peroxide oxidation co catalysis of the modeled microanalytical system based on the hybrid palladium nanoparticles (Pd-NPs) with tailored functional properties were studied. By an accurate tuning and validation of the experimental setup, a modular Pd-NPs-doped one-pot/one-electrode amperometric nanobiosensor for advanced multiplex analyte detection was constructed. The specific operational conditions (electrochemical read-out mode, pH, regeneration procedure) of the modular one-pot/one-electrode nanobiosensor allowed a reliable sensing of L-lactate (with linear dynamic range, LDR = 500 µM – 2 mM, R2 = 0.977), D-glucose (with LDR = 200 µM – 50 mM, R2 = 0.987), hydrogen peroxide (with LDR = 20 µM – 100 mM, R2 = 0.998) and glutaraldehyde (with LDR = 1 – 100 mM, R2 = 0.971). In addition, mechanistic aspects influencing the performance of Pd-NPs-doped one-pot/ one-electrode for multiplex analyte sensing were studied in detail. The designed one-pot/one-electrode amper ometric nanobiosensor showed a thin layer electrochemical behavior that greatly enhanced electron transfer between the functional hybrid layer and the electrode. Finally, a specific regeneration procedure of the hybrid one-pot/one-electrode and algorithm towards its usage for modular biocatalysis were developed. The reported strategy can readily be considered as a guideline towards the fabrication of commercialized nanobiosensors with tailored properties for advanced modular biocatalysis

Application of Organic-Inorganic Hybrids in Chemical Analysis, Bio- and Environmental Monitoring

Organic-inorganic hybrids (OIH) are considered to be a powerful platform for applications in many research and industrial fields. This review highlights the application of OIH for chemical analysis, biosensors, and environmental monitoring. A methodology toward metrological traceability measurement and standardization of OIH and demonstration of the role of mathematical modeling in biosensor design are also presented. The importance of the development of novel types of OIH for biosensing applications is highlighted. Finally, current trends in nanometrology and nanobiosensors are presented

Ionospheric phenomena before strong earthquakes

A statistical analysis of several ionospheric parameters before earthquakes with magnitude <i>M</i> <u>></u> 5.5 located less than 500 km from an ionospheric vertical sounding station is performed. Ionospheric effects preceding &quot;deep&quot; (depth <i>h</i> > 33 km) and &quot;crust&quot; (<i>h</i> <u><</u> 33 km) earthquakes were analysed separately. Data of nighttime measurements of the critical frequencies <i>fo</i>F2 and <i>fo</i>Es, the frequency <i>fb</i>Es and Es-spread at the middle latitude station Dushanbe were used. The frequencies <i>fo</i>F2 and <i>fb</i>Es are proportional to the square root of the ionization density at heights of 300 km and 100 km, respectively. It is shown that two days before the earthquakes the values of <i>fo</i>F2 averaged over the morning hours (00:00 LT–06:00 LT) and of <i>fb</i>Es averaged over the nighttime hours (18:00 LT–06:00 LT) decrease; the effect is stronger for the &quot;deep&quot; earthquakes. Analysing the coefficient of semitransparency which characterizes the degree of small-scale turbulence, it was shown that this value increases 1–4 days before &quot;crust&quot; earthquakes, and it does not change before &quot;deep&quot; earthquakes. Studying Es-spread which manifests itself as diffuse Es track on ionograms and characterizes the degree of large-scale turbulence, it was found that the number of Es-spread observations increases 1–3 days before the earthquakes; for &quot;deep&quot; earthquakes the effect is more intensive. Thus it may be concluded that different mechanisms of energy transfer from the region of earthquake preparation to the ionosphere occur for &quot;deep&quot; and &quot;crust&quot; events

Electrochemical operational principles and analytical performance of Pd-based amperometric nanobiosensors

Palladium nanoparticles (Pd-NPs) have been approved as an effective catalyst for hydrogen peroxide decomposition which is released during specific enzymatic reactions. However, the general operational principles and electrochemical performance of Pd-NPs-based nanobiosensors have been poorly exploited. Here, the electrochemical behavior of oxidase-associated peroxide oxidation co-catalysis of the modelled microanalytical system based on screen-printed electrodes modified by electroplated PdNPs as an electrocatalyst, glucose oxidase (GOx) or alcohol oxidase (AOx) as a bioreceptor and the ionomer Nafion as a polymeric binding agent was studied in detail. The impact of palladium surface oxides and adsorbed oxygen on the activity and product selectivity in an oxidase type of nanobiosensor was ascertained. To avoid PdO and oxygen electroreduction affecting the entire amperometric response of Pd-NPs-based nanobiosensors, a special two-step polarization procedure was proposed. Under the established electrochemical conditions, Pd-NPs-based nanobiosensors with encapsulated oxidases showed a wide dynamic range towards selective bioanalyte detection, excellent basic line stability, accuracy and resistance to the presence of interfering electrochemical species. This work can serve as a guideline for the search and validation of operational principles of novel biosensors based on nanoparticles

One-Pot Synthesis of Copper Iodide-Polypyrrole Nanocomposites

A novel one-pot chemical synthesis of functional copper iodide-polypyrrole composites, CuI-PPy, has been proposed. The fabrication process allows the formation of nanodimensional metal salt/polymer hybrid structures in a fully controlled time- and concentration-dependent manner. The impact of certain experimental conditions, viz., duration of synthesis, sequence of component addition and concentrations of the intact reagents on the structure, dimensionality and yield of the end-product was evaluated in detail. More specifically, the amount of marshite CuI within the hybrid composite can be ranged from 60 to 90 wt.%, depending on synthetic conditions (type and concentration of components, process duration). In addition, the conditions allowing the synthesis of nano-sized CuI distributed inside the polypyrrole matrix were found. A high morphological stability and reproducibility of the synthesized nanodimensional metal-polymer hybrid materials were approved. Finally, the electrochemical activity of the formed composites was verified by cyclic voltammetry studies. The stability of CuI-PPy composite deposited on the electrodes was strongly affected by the applied anodic limit. The proposed one-pot synthesis of the hybrid nanodimensional copper iodide-polypyrrole composites is highly innovative, meets the requirements of Green Chemistry and is potentially useful for future biosensor development. In addition, this study is expected to generally contribute to the knowledge on the hybrid nano-based composites with tailored properties