No abstract

No abstract

A simple, yet versatile strategy to prepare size-controlled and monodisperse carbon sub-micrometer spheres is developed based on the biomolecule dopamine. Unlike traditional carbon materials, the resulting carbon sub-micrometer spheres contain much less sp(3) carbon with high-level electroactive nitrogen. Moreover, metal-carbon hybrid sub-micrometer spheres can be easily obtained, and show highly promising catalytic properties in the oxygen-reduction reaction.

Nanotechnology-mediated antioxidative therapy is emerging as a novel strategy for treating a myriad of important diseases through scavenging excessive reactive oxygen and nitrogen species (RONS), a mechanism critical in disease development and progression. However, similar to antioxidative enzymes, currently studied nano-antioxidants have demonstrated scavenging activity to specific RONS, and sufficient antioxidative effects against multiple RONS generated in diseases remain elusive. Here we propose to develop bioinspired melanin nanoparticles (MeNPs) for more potent and safer antioxidative therapy. While melanin is known to function as a potential radical scavenger, its antioxidative mechanisms are far from clear and its applications for the treatment of RONS-associated diseases have yet to be well explored. In this study, we provide for the first time exhaustive characterization of the activities of MeNPs against multiple RONS including O2•−, H2O2, •OH, •NO, and ONOO−, the main toxic RONS generated in diseases. The potential of MeNPs for antioxidative therapy has also been evaluated in vitro and in a rat model of ischemic stroke. In addition to the broad defense against these RONS, MeNPs can also attenuate the RONS-triggered inflammatory responses through suppressing the expression of inflammatory mediators and cytokines. In vivo results further demonstrate that these unique multi-antioxidative, anti-inflammatory and biocompatible features of MeNPs contribute to their effective protection of ischemic brains with negligible side effects.

The color change induced by triple hydrogen-bonding recognition between melamine and a cyanuric acid derivative grafted on the surface of gold nanoparticles can be used for reliable detection of melamine. Since such a color change can be readily seen by the naked eye, the method enables on-site and real-time detection of melamine in raw milk and infant formula even at a concentration as low as 2.5 ppb without the aid of any advanced instruments.

A simple one step solvothermal strategy using non-toxic and cost-effective precursors has been developed to prepare magnetite/reduced graphene oxide (MRGO) nanocomposites for removal of dye pollutants. Taking advantage of the combined benefits of graphene and magnetic nanoparticles, these MRGO nanocomposites exhibit excellent removal efficiency (over 91% for rhodamine B and over 94% for malachite green) and rapid separation from aqueous solution by an external magnetic field. Interestingly, the performance of the MRGO composites is strongly dependent on both the loading of Fe 3 O 4 and the pH value. In addition, the adsorption behavior of this new adsorbent fits well with the Freundlich isotherm and the pseudo-second-order kinetic model. In further applications, real samples-including industrial waste water and lake water-have been treated using the MRGO composites. All the results demonstrate that the MRGO composites are effective adsorbents for removal of dye pollutants and thus could provide a new platform for dye decontamination.

Frequent oil spillages and the industrial discharge of organic solvents have not only caused severe environmental and ecological damage, but also create a risk of fire and explosion. Therefore, it is imperative, but also challenging, to find high-performance absorbent materials that are both effective and less flammable. Here we present a superior superhydrophobic sponge that exhibits excellent absorption performance through a combination of its superhydrophobicity, high porosity, and robust stability. More importantly, it inherits the intrinsic flame-retardant nature of the raw melamine sponge, and is thus expected to reduce the risk of fire and explosion when being used as an absorbent for flammable oils and organic compounds. Moreover, the fabrication of this sponge is easy to scale up, since it does not use a complicated process or sophisticated equipment. These characteristics make the sponge a much more competitive product than the commercial absorbent, nonwoven polypropylene fabric.

Molybdenum disulphide (MoS2) has been an attractive target for investigations in the fields of catalysis, sensing, energy storage, electronics, and optoelectronics. However, its potential application in the important area of environmental cleanup has not yet been effectively explored. With an intrinsically sulfur‐rich characteristic and unique 2D structure, MoS2 should be capable of mercury capture and removal. However, successful attempts to apply MoS2 to mercury removal are quite rare, presumably because the vast majority of sulfur atoms are located inside the bulk of MoS2 and are therefore inaccessible for mercury ions. Here, the first experimental evidence that MoS2 nanosheets with widened interlayer spacing are capable of mercury capture, with an extremely high mercury uptake capacity closely matching the theoretically predicted value (2506 mg g−1) and the largest distribution coefficient value (3.53 × 108 mL g−1) is provided. Remarkably, a single treatment of industrial wastewater (polyvinyl chloride industry) with this modified MoS2 could efficiently reduce the mercury concentration (126 p.p.b.) below U.S. Environmental Protection Agency limits for drinking water standards. The findings open up the possibility of expanding the applications of transition metal dichalcogenides in environmental remediation.