Laser synthesis of nanomaterials to create a new family of electrochemical microbiosensors

2020 ◽  
Vol 2 (3) ◽  
pp. 74-88
Author(s):  
Svetlana V. Kochemirovskaya ◽  
Maxim O. Novomlinsky ◽  
Alena A. Fogel ◽  
Vladimir A. Kochemirovsky

A brief review of modern methods for creating materials for enzymeless microbiosensors intended for express analysis of the content of components of biological fluids, including human blood, has been made. New directions of the synthesis of such materials have been described: laser ablation (PLD) and laser-induced deposition (LCLD). The comparison of laser methods for the synthesis of materials of non-enzymatic microbiosensors with the known methods for creating nanostructured materials has been carried out. Using bimetallic LCLD microtracks as an example, the mechanism of enhancing the electrochemical response of the sensor to the content of glucose and hydrogen peroxide in complex organic and biological mixtures has been shown. It is associated with the creation of nano- and microstructured materials with a highly developed surface, on which there are extended boundaries of the interphase contact zones. This creates numerous activated acid-base centers. They facilitate the transfer of charge from the oxidizing agent to the reducing agent in the solution in contact with the sensor surface. A comparison of the sensory properties of microcomposite bimetallic deposits synthesized by the laser method and their analogs synthesized by traditional methods has been carried out. The advantages of laser methods for the synthesis of microcomposite sensor-active materials are discussed: the miniature size of the sensors, the possibility of using inexpensive metals instead of precious ones, the environmental friendliness of the methods, and the absence of the need to pre-activate the surface

Author(s):  
V. Shuvalov

The article discusses new directions in the development of the architecture of recreational facilities in South-east Asia, which need to be implemented to form a modern recreational and tourist cluster in Bangladesh. The author reveals compositional, spatial-planning, decorative-stylistic, functional and design features in the architecture of recreational objects made of bamboo. It is proposed to build the main accommodation facilities (hotels, hotels, motels, arrival houses and houses with the status of "second homes") and food facilities (cafes, bars, canteens, restaurants) using traditional ecological materials. Modern methods of energy saving, their implementation in the practice of design and construction in countries with hot and humid climates are listed. When designing recreational and tourist complexes, innovative technologies, materials and structures are introduced that increase the comfort of recreational facilities. The government relies on the development of the recreational tourism industry in the country, creating economic advantages in the development of this business in the Republic of Bangladesh, increasing the investment attractiveness for domestic and foreign investors, offering preferential tax and customs regimes for the construction and operation of recreational and tourist facilities. Many facilities of the recreational and tourist industry, built in the period 1980-2010 do not meet modern requirements for energy efficiency, environmental friendliness and aesthetic appeal, which definitely has a negative impact on the recreational attractiveness of some regions of the country, this is especially important for remote and difficult to access areas where created objects.


Author(s):  
M. Antonenko ◽  
Yu. Ogurtsova ◽  
V. Strokova ◽  
E. Gubareva

The paper reviews the available technologies for producing photocatalytic active self-cleaning materials based on cement, including concretes and dry building mixtures. Used photocatalytic additives and their influence on the cement system are considered. The applied methods for assessing the photocatalytic activity of self-cleaning cement materials are presented. The compositions of concrete mixtures, their properties, areas and prospects of application are analyzed. The main problems of development, production and application of photocatalytic active self-cleaning materials based on cement are presented. The main directions to increase the self-cleaning ability of photocatalytic active materials based on cement are: optimization of the microstructure of the photocatalyst and the composite with its use in the direction of creating a developed surface of the photocatalyst - hierarchical microstructure; it intensifies the diffusion processes of photocatalytic reaction reagents and increases the contact area photocatalyst with a pollutant; it absorbs and accumulates ultraviolet radiation waves; optimization of the phase composition of titanium dioxide - search for the ratio of the anatase and rutile phases, at which the maximum photocatalytic activity is achieved; choosing of economically feasible method for periodical updating of the surface of concrete products carbonized during operation in order to restore self-cleaning ability.


Author(s):  
Mintu Maan Dutta

Nanotechnology has emerged as one of the most promising tools for the present revolution in the field of agri-food sector. Engineered nano materials (ENMs) are a part of nanotechnology which has led to the invention of smart and active materials such as nanosensors, nanofertilizers, nanopesticides, etc. Bioinspired and biosynthesis approach for the synthesis of nanomaterials using various eco-friendly green chemistry methods has overcome the various problem associated with the use of toxic chemicals and harsh reaction conditions. Thus, use of these nanomaterial in this sector has tremendously increased the crop yield and quality thereby reducing the use of toxic crop protecting agents.


2019 ◽  
Vol 42 ◽  
Author(s):  
Penny Van Bergen ◽  
John Sutton

Abstract Sociocultural developmental psychology can drive new directions in gadgetry science. We use autobiographical memory, a compound capacity incorporating episodic memory, as a case study. Autobiographical memory emerges late in development, supported by interactions with parents. Intervention research highlights the causal influence of these interactions, whereas cross-cultural research demonstrates culturally determined diversity. Different patterns of inheritance are discussed.


1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.


Author(s):  
Y. P. Lin ◽  
J. S. Xue ◽  
J. E. Greedan

A new family of high temperature superconductors based on Pb2Sr2YCu3O9−δ has recently been reported. One method of improving Tc has been to replace Y partially with Ca. Although the basic structure of this type of superconductors is known, the detailed structure is still unclear, and various space groups has been proposed. In our work, crystals of Pb2Sr2YCu3O9−δ with dimensions up to 1 × 1 × 0.25.mm and with Tc of 84 K have been grown and their superconducting properties described. The defects and crystal symmetry have been investigated using electron microscopy performed on crushed crystals supported on a holey carbon film.Electron diffraction confirmed x-ray diffraction results which showed that the crystals are primitive orthorhombic with a=0.5383, b=0.5423 and c=1.5765 nm. Convergent Beam Electron Diffraction (CBED) patterns for the and axes are shown in Figs. 1 and 2 respectively.


Author(s):  
Martin Poenie ◽  
Akwasi Minta ◽  
Charles Vorndran

The use of fura-2 as an intracellular calcium indicator is complicated by problems of rapid dye leakage and intracellular compartmentalization which is due to a probenecid sensitive anion transporter. In addition there is increasing evidence for localized microdomains of high calcium signals which may not be faithfully reported by fura-2.We have developed a new family of fura-2 analogs aimed at addressing some of these problems. These new indicators are based on a modified bapta which can be readily derivatized to produce fura-2 analogs with a variety of new properties. The modifications do not affect the chromophore and have little impact on the spectral and metal binding properties of the indicator. One of these new derivatives known as FPE3 is a zwitterionic analog of fura-2 that can be loaded into cells as an acetoxymethyl ester and whose retention in cells is much improved. The improved retention of FPE3 is important for both cuvettebased measurements of cell suspensions and for calcium imaging.


Author(s):  
CE Bracker ◽  
P. K. Hansma

A new family of scanning probe microscopes has emerged that is opening new horizons for investigating the fine structure of matter. The earliest and best known of these instruments is the scanning tunneling microscope (STM). First published in 1982, the STM earned the 1986 Nobel Prize in Physics for two of its inventors, G. Binnig and H. Rohrer. They shared the prize with E. Ruska for his work that had led to the development of the transmission electron microscope half a century earlier. It seems appropriate that the award embodied this particular blend of the old and the new because it demonstrated to the world a long overdue respect for the enormous contributions electron microscopy has made to the understanding of matter, and at the same time it signalled the dawn of a new age in microscopy. What we are seeing is a revolution in microscopy and a redefinition of the concept of a microscope.Several kinds of scanning probe microscopes now exist, and the number is increasing. What they share in common is a small probe that is scanned over the surface of a specimen and measures a physical property on a very small scale, at or near the surface. Scanning probes can measure temperature, magnetic fields, tunneling currents, voltage, force, and ion currents, among others.


2019 ◽  
Vol 10 (45) ◽  
pp. 6116-6121 ◽  
Author(s):  
Tan Ji ◽  
Lei Xia ◽  
Wei Zheng ◽  
Guang-Qiang Yin ◽  
Tao Yue ◽  
...  

We present a new family of porphyrin-functionalized coordination star polymers prepared through combination of coordination-driven self-assembly and post-assembly polymerization. Their self-assembly behaviour in water and potential for photodynamic therapy were demonstrated.


Addiction ◽  
1997 ◽  
Vol 92 (11) ◽  
pp. 1411-1422 ◽  
Author(s):  
Anthony P. Shakeshaft ◽  
Jenny A. Bowman ◽  
Rob W. Sanson-Fisher
Keyword(s):  

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