Surface Enhanced Raman Scattering Studies of Silver-gold Normal and Inverted Core-shell Nanostructures on their Efficiency of Detecting Molecules

AbstractThe intense significance of biological molecules in our everyday lives has prompted the research into the analysis, identification and quantification of these molecules. Recently, surface-enhanced Raman scattering (SERS) study is identified as one of the effective techniques to detect and quantify such bio-molecules, as these processes are indispensable in order to use them in biological applications. Such detection of molecules by SERS depends predominantly upon SERS active metal substrates such as the typical colloidal silver-gold nanostructures. However, identifying and fabricating suitable metal nanostructures for detecting such biomolecules is an essential need to implement them for practical applications particularly in extensive physiological environments. Herein, we report the synthesis of Ag-Au normal and inverted core-shell nanostructures and investigation of their plasmonic properties to detect drug molecules such as methylene blue and methyl orange using the surface enhanced Raman scattering technique. Our investigation promises for an easy reproduction of biocompatible silver-gold bimetallic core-shell nanostructures that possess excellent chemical stability which can be ideal candidates for a wide range of biomedical applications

Structural, electrical transport and optical studies of Li ion doped ZnO nanostructures

In the present work, we studied the morphological aspects, electrical transport and optical properties of pure and lithium ion doped semiconducting ZnO nanostructures successfully prepared by a co-precipitation method. The effect of lithium doping and various morphologies on the structural, electrical and optical properties of these nanostructures were investigated. The X-ray diffraction (XRD) pattern demonstrated that the Li doped ZnO nanostructures exhibits the hexagonal wurtzite structure. A slight change in the 101 peak position was detected among the samples with various morphologies. The UV-Vis diffused reflectance spectroscopic (DRS) studies showed that the band gap increases with Li doping, due to the Burstein-Moss band filling effect. Photoluminescence (PL) studies confirm that the Li incorporation into ZnO material can induce oxygen enrichment of ZnO surface that leads to increase the cyan emission. This material could be used in light emitting diodes in nanoscale optoelectronic devices

Role of sintering temperature dependent crystallization of bioactive glasses on erythrocyte and cytocompatibility

Bioglass (BG) was prepared by sol-gel method and the role of sintering temperatures (600, 700 and 800 °C) on crystalline phase changes, bioactivity, erythrocyte and MG-63 cell line compatibility was investigated. Increase in sintering temperature from 600 to 800 °C led to the secondary phase formation that was confirmed through structural analysis. Micrographics revealed the formation of nanorods (700 °C) and nanoflake like (800 °C) morphologies. Biocompatibility assay showed that, BG sintered at 600 °C had optimal biocompatibility while better mechanical property was noted at 700 °C. Altogether, the study demonstrated that increasing the sintering temperature will result in increased crystallinity which in turn resulted in the optimal biomineralization but decreased the biocompatibility. Hence, we demonstrated the importance of temperature during the processing of BG for various applications, as it affects many properties including bioactivity and compatibility

An enduring in vitro wound healing phase recipient by bioactive glass-graphene oxide nanocomposites

Bioactive glass (BG) is an interesting topic in soft tissue engineering because of its biocompatibility and bonding potential to increase fibroblast cell proliferation, synthesize growth factors, and stimulate granulation tissue development. The proposed BG with and without sodium (Na), prepared by the sol–gel method, is employed in wound healing studies. The BG/graphene oxide (GO) and BG (Na-free)/GO nanocomposites were investigated against fibroblast L929 cells in vitro; the 45S5 BG nanocomposites exhibited desired cell viability (80%), cell proliferation (30%), cell migration (25%), metabolic activity, and wound contraction due to extracellular matrix (ECM) production and enhanced protein release by fibroblast cells. Additionally, the antioxidant assays for BG, BG (Na-free), GO, and BG/GO, BG (Na-free)/GO were evaluated for effective wound healing properties. The results showed decreased inflammation sites in the wound area, assessed by the (2,2-diphenyl-1-picryl-hydrazyl-hydrate) (DPPH) assay with ~ 80% radical scavenging activity, confirming their anti-inflammatory and improved wound healing properties

Therapeutic implications of current Janus kinase inhibitors as anti-COVID agents: A review

Severe cases of COVID-19 are characterized by hyperinflammation induced by cytokine storm, ARDS leading to multiorgan failure and death. JAK-STAT signaling has been implicated in immunopathogenesis of COVID-19 infection under different stages such as viral entry, escaping innate immunity, replication, and subsequent inflammatory processes. Prompted by this fact and prior utilization as an immunomodulatory agent for several autoimmune, allergic, and inflammatory conditions, Jakinibs have been recognized as validated small molecules targeting the rapid release of proinflammatory cytokines, primarily IL-6, and GM-CSF. Various clinical trials are under investigation to evaluate Jakinibs as potential candidates for treating COVID-19. Till date, there is only one small molecule Jakinib known as baricitinib has received FDA-approval as a standalone immunomodulatory agent in treating critical COVID-19 patients. Though various meta-analyses have confirmed and validated the safety and efficacy of Jakinibs, further studies are required to understand the elaborated pathogenesis of COVID-19, duration of Jakinib treatment, and assess the combination therapeutic strategies. In this review, we highlighted JAK-STAT signalling in the pathogenesis of COVID-19 and clinically approved Jakinibs. Moreover, this review described substantially the promising use of Jakinibs and discussed their limitations in the context of COVID-19 therapy. Hence, this review article provides a concise, yet significant insight into the therapeutic implications of Jakinibs as potential anti-COVID agents which opens up a new horizon in the treatment of COVID-19, effectively

Electrochemical Performance of Nitrogen-Doped TiO2 Nanotubes as Electrode Material for Supercapacitor and Li-Ion Battery

Electrochemical anodized titanium dioxide (TiO2) nanotubes are of immense significance as electrochemical energy storage devices owing to their fast electron transfer by reducing the diffusion path and paving way to fabricating binder-free and carbon-free electrodes. Besides these advantages, when nitrogen is doped into its lattice, doubles its electrochemical activity due to enhanced charge transfer induced by oxygen vacancy. Herein, we synthesized nitrogen-doped TiO2 (N-TiO2) and studied its electrochemical performances in supercapacitor and as anode for a lithium-ion battery (LIB). Nitrogen doping into TiO2 was confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. The electrochemical performance of N-TiO2 nanotubes was outstanding with a specific capacitance of 835 μF cm−2 at 100 mV s−1 scan rate as a supercapacitor electrode, and it delivered an areal discharge capacity of 975 μA h cm−2 as an anode material for LIB which is far superior to bare TiO2 nanotubes (505 μF cm−2 and 86 μA h cm−2, respectively). This tailor-made nitrogen-doped nanostructured electrode offers great promise as next-generation energy storage electrode material.publishedVersio

Growth of lead calcium titanate single crystals and their characterization

Ferroelectrics2073-4497-505FERO

Morphology and etching studies on YBCO and CuO single crystals

Physica C: Superconductivity and its Applications319199-103PHYC

Ferroelectric domain structure studies on PbTiO3 single crystals by polarizing microscope, SEM and AFM

Ferroelectrics2311 -4 pt 3637/49 - 642/54FERO