Formation of Self-Assembled Nanowires from Copper Nanoparticles Synthesized by the Electro-Explosion of Wires Technique-Study of the Time-Dependent Structural and Functional Evolution.

We report here the formation of Cu nanowires (CuNWs) from Cu nanoparticles (CuNPs) by a self-assembly process. The CuNPs were synthesized by the electro-explosion of wire (EEW) technique that included nonequilibrium processes for the synthesis. Structural evolution in terms of aggregation or nanowire formation in the samples was observed when the CuNPs were kept for a month after synthesis in a glass vial without the application of any external driving force. The emergence of tangled CuNWs was noticed at the bottom of the vials only when no agitation or aeration was allowed. The nanowires were characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Thermal oxidation of the nanowire samples implied that they could convert into rod-shaped structures. Loss of functionality was also observed in the hemoglobin precipitation study conducted to compare the activity of freshly prepared CuNPs and CuNWs. From the above observations, we conclude that the CuNP, after synthesis, possesses a huge amount of energy, and attainment of equilibrium occurs through either aggregation (clustering) or ordered self-assembly, depending on the conditions applied.

Natural Occurrence of Carbon Dots during In Vitro Nonenzymatic Glycosylation of Hemoglobin A0.

Carbon dots, the nanostructures of carbon, have excellent optical and chemical properties and find a range of applications in various fields of biology and medicine. In the current study, carbon dots are synthesized using in vitro nonenzymatic glycosylation at 37 °C, which is the conventional method for the synthesis of Advanced Glycosylation End products. While comparing the physicochemical properties using a series of physical and chemical analyses including light absorption, fluorescence, photoluminescence, chemical composition, functional group analysis, and in vitro imaging, striking similarities are found among Carbon dots and Advanced Glycosylation End products. Based on the evident resemblance between the two, we propose either the presence of a common structural backbone or the coexistence of the two individual chemical entities. Thus, the formation of carbon dots at physiological temperatures raises health concerns as nonenzymatic glycosylation is a physiological process in humans and the rate of which is elevated during diabetes. The Advanced Glycosylation End products are known to have a detrimental effect in diabetic patients, and the chemical similarity between the two questions the widely studied biocompatibility of carbon dots.

A method to detect immunoreactions on the basis of current vs. concentration slope - an electrochemical approach.

The emergence of novel infectious diseases is rising with time and is a major threat to the society. The recent outbreak of infectious coronavirus disease has made a huge impact in our lives. The massive outbreak of the disease revealed that there is room for development of new diagnostics tools and methods to screen huge numbers of samples in the shortest possible time. Our current work relates to an electronic diagnostic system and method that rapidly detects the presence of an antigen in solution. Our designed system is capable of separating the immunocomplex formation on the basis of the slope it produces in contrast to the controls, when oxidation peak current is plotted against the concentration of the reactant after electrochemistry measurement. In this system, antibody conjugated copper nanoparticles synthesized by the electroexplosion method has played the key role. The values of the slopes of copper nanoparticles (CuNPs) was found to be -3.7637, whereas those for CuNP conjugated Antibody and CuNPAntibodyAntigen were -2.3044 and -0.8332, respectively. Hence, the current method could become one of the easiest and fastest method for the electronic detection of an immune reaction and a good replacement for the time-consuming, label-based assays in multistep reaction.

Neuronal adhesion and growth on nanopatterned EA5-POPC synthetic membranes.

Biomimetic membranes create opportunities for various applications, including the possibility of replacing interacting cells in a cell-cell contact. Here we have fractionated synthetic membranes using metal nano-grid structures where EphrinA5 (EA5), a neuronal adhesion promoter, was anchored via its Fc domain (immunoglobulin G (IgG)-domain). FRAP experiments were performed to check the confinement of the synthetic membrane within these nano-structures. Rat cortical primary neurons were cultured and live cell imaging techniques were used to monitor the neuronal interaction with these fractionated synthetic membranes. Computational imaging analysis of the corresponding images elucidated interesting details of the cellular behavior. The phenotypic cellular response on these nano-membrane fractions was found to be similar to that on non-fractionated synthetic membranes indicating that although the number of focal adhesion points was low (due to the reduced EA5 number) in the nano-sized membrane patches perhaps some other factors like metal grid boundaries might be playing a role in rendering the similarity.

Synthesis of graphenized Au/ZnO plasmonic nanocomposites for simultaneous sunlight mediated photo-catalysis and anti-microbial activity.

Sunlight mediated photo-degradation and anti-bacterial activity of hetero junctioned plasmonic binary (Au/ZnO, RGO/ZnO) and ternary (RGO/Au/ZnO) nanocomposites (NC) have been reported. Higher photo-charge carrier generation, increased charge separation, improved active sites for catalysis, enhanced LSPR and larger photo-response regions have been achieved. Decoration with Au nanoparticles (ca. 11 ±â€¯3 and 48 ±â€¯5 nm) and RGO of ZnO (3D/1D) microstructures (aspect ratio 15.18) provides ternary NCs an edge over mono/bi component catalysts. The ternary NC have shown improved dye degradation capacity with 100% efficiency (5 µM MB solution) and average adsorption degradation capacity (Q°) of 83.34 mg/g within 30 min of sunlight exposure (900 ±â€¯30 Wm-2). Elaborated studies by varying reaction parameters like initial dye concentration, contact time, type of NCs and initial loading of NCs reveals pseudo first order degradation kinetics. 100% microbial killing of Gram positive S.aureus strain with 60 µg/ml of NC using sunlight as activator has proven the simultaneous multiple functionality of the NC. Further, facile green one pot hydrothermal synthesis with water as reaction medium, absence of photo-corrosion of NCs, regeneration ability (ca. 90% for 10 µM solution) of NCs, projects a broader potential application of the synthesized NCs and could reduce the continuous requirement of such material, limiting the environmental toxicity.