Chronoamperometric study of elemental sulphur (S) nanoparticles (NPs) in NaCl water solution: new methodology for S NPs sizing and detection

The important role of the interaction between manganese minerals and metals in environmental remediation: a review

With illegal discharge of wastewater containing inorganic and organic pollutants, combined pollution is common and needs urgent attention. Understanding the migration and transformation laws of pollutants in the environment has important guiding significance for environmental remediation. Due to the characteristics of adsorption, oxidation, and catalysis, manganese minerals play important role in the environment fate of pollutants. This review summarizes the forms of interaction between manganese minerals and metals, the environmental importance of the interaction between manganese minerals and metals, and the contribution of this interaction in improving performance of Mn-based composite for environmental remediation. The literatures have indicated that the interactions between manganese minerals and metals involve in surface adsorption, lattice replacement, and formation of association minerals. The interaction between manganese minerals and metals plays an important role in environmental behavior of element and environmental significance of manganese minerals. The synergistic or antagonistic effect resulted from the interaction influence the purification of heavy metal and organism pollutant. The synergistic effect benefited from the coordination of adsorption and oxidation, convenient electron transfer, abundant oxygen vacancies, and fast migration of lattice oxygen. Based on the synergy, Mn-based composites have been widely used for environmental remediation. The synthesize methods of Mn-based composites mainly include homogeneous coprecipitation, chemical etching route, hydrothermal, homogeneous chelating sol-gel, and ethylene glycol reduction strategy. This review is helpful to fully understand the migration and transformation process of pollutants in the environment, expand the resource utilization of manganese minerals for environmental remediation.

Sulfur Nanoparticles with Novel Morphologies Coupled with Brain-Targeting Peptides RVG as a New Type of Inhibitor Against Metal-Induced Aβ Aggregation

Functionalized nanomaterials, which have been applied widely to inhibit amyloid-β protein (Aβ) aggregation, show enormous potential in the field of prevention and treatment of Alzheimer's disease (AD). A significant body of data has demonstrated that the morphology and size of nanomaterials have remarkable effects on their biological behaviors. In this work, we proposed and designed three kinds of brain-targeting sulfur nanoparticles (RVG@Met@SNPs) with novel morphologies (volute-like, tadpole-like, and sphere-like) and investigated the effect of different RVG@Met@SNPs on Aβ-Cu²⁺ complex aggregation and their corresponding neurotoxicity. Among them, the sphere-like nanoparticles (RVG@Met@SS) exhibited the most effective inhibitory activity, due to their unique mini size effect, and they reduced 61.6% the Aβ-Cu²⁺ complex aggregation and increased 92.4% SH-SY5Y cell viability in a dose of 10 μg/mL. In vitro and in vivo, the abilities of different morphologies of RVG@Met@SNPs to cross the blood-brain barrier (BBB) and target brain parenchymal cells were significantly different. Moreover, improvements in learning disability and cognitive loss were shown in the transgenic AD mice model using the Morris water maze test after multiple doses of RVG@Met@SNPs treatment. In general, the purpose of this research is to develop a biological application of sulfur nanoparticles and to provide a novel functionalized nanomaterial to treat AD.

Bio‐inspired synthesis of sulphur nanoparticles using leaf extract of four medicinal plants with special reference to their antibacterial activity

We report new, eco‐friendly and green method for the synthesis of sulphur nanoparticles using sodium polysulphide in the presence of leaf extracts of four different medicinal plants, which can be used for treatment of bacterial infections. Sodium polysulphide and acidic solution (H2 SO4) in the presence of plant leaf extract developed the yellowish precipitate in solution, which indicated the formation of sulphur nanoparticles. UV–Vis spectrophotometer analysis of reaction mixture showed absorbance spectra in the range of 292–296 nm, which is supposed to be specific for sulphur nanoparticles. Zeta potential study of sulphur nanoparticles synthesized from Catharanthus roseus showed more stability when compared with other medicinal plants. Sulphur nanoparticles synthesized from C. roseus were further characterized by XRD analysis, FTIR analysis, and TEM analysis. The biogenic sulphur nanoparticles were spherical, polydispersed with particle size of 70–80 nm. Evaluation of antibacterial study revealed that synthesized sulphur nanoparticles exhibited better bactericidal efficacy against common pathogenic bacteria Escherichia coli and Staphylococcus aureus with minimum inhibitory concentration of 200 μg/ml with significant activity used in combination with antibiotic. It can be concluded that the synthesized sulphur nanoparticles can be used as antibacterial agents after thorough experimental trials in animals.