Liquid Phase Isolation of SnS Monolayers with Enhanced Optoelectronic Properties.

Recent advances in atomically thin two dimensional (2D) anisotropic group IVA -VI metal monochalcogenides (MMCs) and their fascinating intrinsic properties and potential applications are hampered due to an ongoing challenge of monolayer isolation. Among the most promising MMCs, tin (II) sulfide (SnS) is an earth-abundant layered material with tunable bandgap and anisotropic physical properties, which render it extraordinary for electronics and optoelectronics. To date, however, the successful isolation of atomically thin SnS single layers at large quantities has been challenging due to the presence of strong interlayer interactions, attributed to the lone-pair electrons of sulfur. Here, a novel liquid phase exfoliation approach is reported, which enables the overcome of such strong interlayer binding energy. Specifically, it demonstrates that the synergistic action of external thermal energy with the ultrasound energy-induced hydrodynamic force in solution gives rise to the systematic isolation of highly crystalline SnS monolayers (1L-SnS). It is shown that the exfoliated 1L-SnS crystals exhibit high carrier mobility and deep-UV spectral photodetection, featuring a fast carrier response time of 400 ms. At the same time, monolayer-based SnS transistor devices fabricated from solution present a high on/off ratio, complemented with a responsivity of 6.7 × 10-3 A W-1 and remarkable stability upon prolonged operation in ambient conditions. This study opens a new avenue for large-scale isolation of highly crystalline SnS and other MMC manolayers for a wide range of applications, including extended area nanoelectronic devices, printed from solution.

ZnO NPs immobilized by Alizarin as in vitro predictive and imaging biomarkers for protein amyloidosis.

Protein amyloidosis represents the main pathological hallmark of many incurable neurodegenerative disorders and protein misfolding diseases. Nanomaterials-based approaches give rise to diagnosis and/or prediction of these proteinopathies, with regards to the multifactorial nature of their pathogenesis. Herein, crystalline truncated hexagonal shaped naked ZnO nanoparticles (mean value 47.4 nm) have been solvothermally prepared and immobilized further with alizarin (Alzn) molecules (54%) to stand up to amyloidosis acting both as inhibitors and imaging agents, as well as antioxidants. Thioflavin-T (ThT) assay revealed that the resulted zinc oxide nanoparticles immobilized with alizarin (ZnO@Alzn NPs) inhibited in vitro insulin amyloids formation in a dose-dependent manner, while the kinetic mechanism of the phenomenon was recorded. In parallel, amyloid oligomers and plaques have been visualized by conventional optical microscopy upon protein co-incubation with ZnO@Alzn NPs, highlighting the imaging ability of the immobilized NPs. The antioxidant activity was monitored by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, through which it was shown that alizarin incorporation onto the inorganic core leads to the reduction of IC50 values from 221 µg/mL to 167 µg/mL. The enhanced free radical scavenging effects of ZnO@Alzn compared to the naked-ZnO NPs, features their prospect to serve additional functions.

Effect of Sintering Temperature of Bioactive Glass Nanoceramics on the Hemolytic Activity and Oxidative Stress Biomarkers in Erythrocytes.

INTRODUCTION: The nature of the surface is critical in determining the biological activity of silica powders. A novel correlation between toxicity and surface properties of bioactive glass ceramics (BGCs) synthesized via the sol-gel method was attempted in this study. METHODS: The behavior of BGCs after their attachment to the surface of red blood cells (RBCs) was evaluated and their toxic effects were determined based on hemolysis, membrane injury via anti-phosphotyrosine immunoblot of Band 3, lipid peroxidation, potential to generate reactive oxygen species, and antioxidant enzyme production. In particular, three BGCs were synthesized and treated at three sintering temperatures (T1 = 835 °C, T2 = 1000 °C and T3 = 1100 °C) to investigate possible relation between surface charge or structure and hemolytic potential. RESULTS: Their toxicity based on hemolysis was dose dependent, while BGC-T2 had the best hemocompatibility in compare with the other BGCs.No BGCs in dosages lower than 0.125 mg/mL could damage erythrocytes. On the other hand, all BGCs promoted the production of reactive oxygen species in certain concentrations, with the BGC-T2 producing the lowest ROS and increasing the glutathione levels in RBCs protecting their damage. CONCLUSIONS: The results suggest that various factors such as size, a probable different proportion of surface silanols, a balanced mechanism between calcium and magnesium cellular uptake or the different crystalline nature may have contributed to this finding; however, future research is needed to clarify the underlying mechanisms.