Conventional and Nanotechnology-Based Sensing Methods for SARS Coronavirus (2019-nCoV).

Ongoing pandemic coronavirus (COVID-19) has affected over 218 countries and infected 88,512,243 and 1,906,853 deaths reported by Jan. 8, 2021. At present, vaccines are being developed in Europe, Russia, USA, and China, although some of these are in phase III of trials, which are waiting to be available for the general public. The only option available now is by vigorous testing, isolation of the infected cases, and maintaining physical and social distances. Numerous methods are now available or being developed for testing the suspected cases, which may act as carriers of the virus. In this review, efforts have been made to discuss the conventional as well as fast, rapid, and efficient testing methods developed for the diagnosis of 2019-nCoV.Testing methods can be based on the sensing of targets, which include RNA, spike proteins and antibodies such as IgG and IgM. Apart from the development of RNA targeted PCR, antibody and VSV pseudovirus neutralization assay along with several other diagnostic techniques have been developed. Additionally, nanotechnology-based sensors are being developed for the diagnosis of the virus, and these are also discussed.

Monodispersed core/shell nanospheres of ZnS/NiO with enhanced H2 generation and quantum efficiency at versatile photocatalytic conditions.

This investigation is first to elucidate the synthesis of mono-dispersed ZnS/NiO-core/shell nanostructures with a uniform thin layer of NiO-shell on the ZnS-nanospheres as a core under controlled thermal treatments. NiO-shell thickness varied to 8.2, 12.4, 18.2, and 24.2 nm, while the ZnS-core diameter remained stable about 96 ± 6 nm. The crystalline phase and core/shell structure of the materials were confirmed using XRD and HRTEM techniques, respectively. Optical properties through UV-vis spectroscopy analysis revealed the manifestation of red-shift in the absorption spectrum of core/shell materials, while the XPS analysis of elements elucidated their stable oxidation states in ZnS/NiO core/shell structure. The optimized ZnS/NiO-core/shell showed 1.42 times higher H2 generation (162.1 mmol h-1 g-1cat) than the pristine ZnS-core (113.2 mmol h-1 g-1cat), and 64.5 times higher than the pristine NiO-shell (2.5 mmol h-1 g-1cat). The quantum efficiency at wavelengths of 420, 365 nm, and 1.5 G air mass filters was found to be 13.5%, 25.0%, and 45.3%, respectively. Water splitting experiments was also performed without addition of any additives, which showed enhanced H2 gas evolution of 1.6 mmol h-1 g-1cat under the sunlight illumination. Photoelectrochemical measurements revealed the stable photocurrent density and minimized charge recombination in the system. The performed recyclability and reusability tests for five recycles demonstrated the excellent stability of the developed photocatalysts.

A review on multicomponent reactions catalysed by zero-dimensional/one-dimensional titanium dioxide (TiO2) nanomaterials: Promising green methodologies in organic chemistry.

Heterogeneous catalysis has currently become an emerging tool for the design and development of sustainable manufacturing processes in order to obtain advanced intermediates, fine chemicals, and bioactive molecules. This field has been considered efficient and eco-friendly, as it investigates the utilization of non-hazardous metals for atom-economical reactions. Nanomaterials have created a significant impact on scientific and engineering advancements due to their tunable properties with superior performance over their massive counterparts. Due to the increased demand for heterogeneous catalysts in industries and academia, different transition metal oxides have been made into substantial nanostructures. Among them, titanium dioxide (TiO2) nanomaterials have received more attention on account of their chemical stability, low cost, dual acid-base properties, good oxidation rate and refractive index. Different modifications of TiO2 extend their applications as active catalysts or catalyst supports in diverse catalytic processes, such as photovoltaics, lithium batteries, pigments and others. One-dimensional (1-D) TiO2 nanostructures such as nanotubes, nanowires and nanorods have achieved greater importance owing to the unique properties of improved porosity, decreased inter-crystalline contacts, large surface-to-volume ratio, superior dispersibility, amplified accessibility of hydroxyl (-OH) groups and presence of good concentrations of Brønsted/Lewis acid sites. Since the discovery, 1-D TiO2 nanostructures have served good photocatalytic applications, but were less explored in organic transformations. While many articles and reviews have covered the applications of 0-D and 1-D TiO2 nanostructured materials (NSMs) in photoelectrochemical reactions and solar cells, there are other interesting applications of these as well. In contrast to the conventional multi-step processes that utilise the stepwise formation of individual bonds, one-pot conversions based on multicomponent reactions (MCRs) have acquired much significance in contemporary organic synthesis. This paper presents a critical review on history, classification, design and synthetic utility of titania-based nanostructures, which could be used as robust solid-acid catalysts and catalyst supports for MCRs. Further, to put ideas into perspective, the introduction and applications of MCRs for various organic transformations have been discussed.

Photocatalytic hydrogen production from dye contaminated water and electrochemical supercapacitors using carbon nanohorns and TiO2 nanoflower heterogeneous catalysts.

In this research, efficient and novel catalysts based on hierarchical carbon nanohorns-titanium nanoflowers have been prepared by one-pot solvothermal process. Hydrogen generation from dye-contaminated water and dye degradation along with electrochemical supercapacitance performance have been investigated using the synthesized hierarchical catalyst to produce 4500 µmol g-1 h-1 of hydrogen from the photocatalytically generated aqueous methylene blue and methyl orange dyes, which were degraded up to 90% under natural solar light irradiation. These results offer a new path to generate hydrogen from the aqueous dyes. The catalysts electrode showed 164.6 F g-1 supercapacitance at 5 mV s-1 scan rate, which is nearly 1.3 and 1.65-times higher than that of pristine titanium nanoflower and carbon nanohorns electrodes, respectively. Such superior results were achieved due to good crystallinity, improved optical absorption strength, strong chemical composition between the two components, and hierarchical morphology as demonstrated from XRD, UV-DRS, TEM, XPS, and Raman spectral characterizations.

Crystal structure and Hirshfeld surface analysis of 2-(4-nitro-phen-yl)-2-oxoethyl benzoate.

The title com-pound, C15H11NO5, is relatively planar, with the planes of the two aromatic rings being inclined to each other by 3.09 (5)°. In the crystal, mol-ecules are linked by a pair of C-H⋯O hydrogen bonds, forming inversion dimers, which enclose an R 2 2(16) ring motif. The dimers are linked by a further pair of C-H⋯O hydrogen-bonds forming ribbons enclosing R 4 4(26) ring motifs. The ribbons are linked by offset π-π inter-actions [centroid-centroid distances = 3.6754 (6)-3.7519 (6) Å] to form layers parallel to the ac plane. Through Hirshfeld surface analyses, the d norm surfaces, electrostatic potential and two-dimensional fingerprint (FP) plots were examined to verify the contributions of the different inter-molecular contacts within the supra-molecular structure. The shape-index surface shows that two sides of the mol-ecule are involved with the same contacts in neighbouring mol-ecules, and the curvedness plot shows flat surface patches that are characteristic of planar stacking.

Crystal structure and Hirshfeld surface analysis of 2-(4-nitro-phen-yl)-2-oxoethyl picolinate.

2-(4-Nitro-phen-yl)-2-oxoethyl picolinate, C14H10N2O5, was synthesized under mild conditions. The chemical and mol-ecular structures were confirmed by single-crystal X-ray diffraction analysis. The mol-ecules are linked by inversion into centrosymmetric dimers via weak inter-molecular C-H⋯O inter-actions, forming R 2 2(10) ring motifs, and further strengthened by weak π-π inter-actions. Hirshfeld surface analyses, the d norm surfaces, electrostatic potential and two-dimensional fingerprint (FP) plots were used to verify the contributions of the different inter-molecular inter-actions within the supra-molecular structure. The shape-index surface shows that two sides of the mol-ecules are involved with the same contacts in neighbouring mol-ecules and curvedness plots show flat surface patches that are characteristic of planar stacking.

Crystal structure and Hirshfeld surface analysis of 2-(4-nitro-phen-yl)-2-oxoethyl 2-chloro-benzoate.

The title compound, C15H10ClNO5, is relatively planar with the two aromatic rings being inclined to each other by 3.56 (11)°. The central -C(=O)-C-O-C(=O)- bridge is slightly twisted, with a C-C-O-C torsion angle of 164.95 (16)°. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯Cl hydrogen bonds, forming layers parallel to the (101) plane. The layers are linked by a further C-H⋯O hydrogen bond, forming a three-dimensional supra-molecular structure. There are a number of offset π-π inter-actions present between the layers [inter-centroid distances vary from 3.8264 (15) to 3.9775 (14) Å]. Hirshfeld surface analyses, the d norm surfaces, electrostatic potential and two-dimensional fingerprint plots were examined to verify the contributions of the different inter-molecular contacts within the supra-molecular structure. The shape-index surface shows that two sides of the mol-ecule are involved in the same contacts with neighbouring mol-ecules, and the curvedness plot shows flat surface patches that are characteristic of planar stacking.

A review on various maleic anhydride antimicrobial polymers.

The basic requirement of human beings is better health but the serious health effects and numerous infections caused by rapid growth of harmful pathogens resulting in a large number of deaths and is a significant challenge to modern science. Microbes infecting humans can be stopped in two ways: disinfectants and antimicrobial agents. There is considerable interest from both academics and industry in antimicrobial polymers due to their favorable properties. Maleic anhydride incredibly bears diverse commercial applications due to its versatile chemical structure. Maleic anhydride is an electron-acceptor monomer where the property comes from reactive double bonds and also reactive anhydride groups. This review presents the development of antimicrobial polymers involving maleic anhydride in the macromolecular structure. This article also addresses the applications of antimicrobial polymers with maleic anhydride in numerous sectors.