共查询到20条相似文献，搜索用时 15 毫秒
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Soumitra Mokashi-Punekar Yicheng Zhou Sydney C. Brooks Nathaniel L. Rosi 《Advanced materials (Deerfield Beach, Fla.)》2020,32(41):1905975
Chiral nanoparticle (NP) superstructures, in which discrete NPs are assembled into chiral architectures, represent an exciting and growing class of nanomaterials. Their enantiospecific properties make them promising candidates for a variety of potential applications. Helical NP superstructures are a rapidly expanding subclass of chiral nanomaterials in which NPs are arranged in three dimensions about a screw axis. Their intrinsic asymmetry gives rise to a variety of interesting properties, including plasmonic chiroptical activity in the visible spectrum, and they hold immense promise as chiroptical sensors and as components of optical metamaterials. Herein, a concise history of the foundational conceptual advances that helped define the field of chiral nanomaterials is provided, and some of the major achievements in the development of helical nanomaterials are highlighted. Next, the key methodologies employed to construct these materials are discussed, and specific merits that are offered by each assembly methodology are identified, as well as their potential disadvantages. Finally, some specific examples of the emerging applications of these materials are discussed and some areas of future development and research focus are proposed. 相似文献
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Yu Hang Leung Alan M. C. Ng Xiaoying Xu Zhiyong Shen Lee A. Gethings Mabel Ting Wong Charis M. N. Chan Mu Yao Guo Yip Hang Ng Aleksandra B. Djurišić Patrick K. H. Lee Wai Kin Chan Li Hong Yu David Lee Phillips Angel P. Y. Ma Frederick C. C. Leung 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(6):1171-1183
The toxicity of metal oxide nanomaterials and their antimicrobial activity is attracting increasing attention. Among these materials, MgO is particularly interesting as a low cost, environmentally‐friendly material. The toxicity of MgO, similar to other metal oxide nanomaterials, is commonly attributed to the production of reactive oxygen species (ROS). We investigated the toxicity of three different MgO nanoparticle samples, and clearly demonstrated robust toxicity towards Escherichia coli bacterial cells in the absence of ROS production for two MgO nanoparticle samples. Proteomics data also clearly demonstrate the absence of oxidative stress and indicate that the primary mechanism of cell death is related to the cell membrane damage, which does not appear to be due to lipid peroxidation. 相似文献
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《Journal of Experimental Nanoscience》2013,8(6):859-867
TiO2 nanotubes have been prepared by anodisation of titanium foil and their antibacterial activities have been tested against Gram-positive bacteria (Bacillus atrophaeus) while photocatalytic activity was tested for the degradation of the methyl orange dye. We found that the annealing temperature strongly affected antibacterial activity and photocatalytic dye degradation, as well as the production of reactive oxygen species under illumination. However, different trends were observed for dye degradation and antibacterial activity dependence on the annealing temperature. The relationship between annealing conditions, crystal structure, reactive oxygen species generation, dye degradation and antibacterial activity is discussed. 相似文献
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Yi He;Mingqin Liu;Yuan Wang;Yiding Liu; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(45):2403216
The color-changing self-assembly and autonomous disassembly of colloidal gold nanoparticles (AuNPs) is reported by simply mixing negatively charged phosphine ligand-capped AuNPs with partially oxidized polyethylene glycol (PEG). The assembly of AuNPs is initiated by PEG adsorption, which disrupts the hydration layer of AuNPs, leading to depletion attraction and reduction of hydration repulsion among the AuNPs. The oxidative species in PEG subsequently oxidize and remove the charged ligands from the AuNP surface, resulting in a decrease and reversal of the negative surface charge. This causes the PEG to adsorb on AuNPs in a tighter and more direct manner, providing strong steric shielding to the AuNPs, thereby triggering the disassembly of the AuNP assemblies. The self-regulated assembly–disassembly process can be tuned widely by controlling chemical conditions of PEG, nanoparticle concentration, and the environmental conditions, suggesting potential applications as colorimetric time-temperature indicators for food and medicine storage conditions. As a proof of concept, it is demonstrated that the lifetime of the color-changing assembly–disassembly process can be extended from tens of minutes to weeks when subjected to a refrigerated environment, with tunability achievable through varying polymer conditions and storage atmospheres. 相似文献
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Ranjith Kumar Kankala Ya-Hui Han Jongbeom Na Chia-Hung Lee Ziqi Sun Shi-Bin Wang Tatsuo Kimura Yong Sik Ok Yusuke Yamauchi Ai-Zheng Chen Kevin C.-W. Wu 《Advanced materials (Deerfield Beach, Fla.)》2020,32(23):1907035
Mesoporous silica nanoparticles (MSNs), one of the important porous materials, have garnered interest owing to their highly attractive physicochemical features and advantageous morphological attributes. They are of particular importance for use in diverse fields including, but not limited to, adsorption, catalysis, and medicine. Despite their intrinsic stable siliceous frameworks, excellent mechanical strength, and optimal morphological attributes, pristine MSNs suffer from poor drug loading efficiency, as well as compatibility and degradability issues for therapeutic, diagnostic, and tissue engineering purposes. Collectively, the desirable and beneficial properties of MSNs have been harnessed by modifying the surface of the siliceous frameworks through incorporating supramolecular assemblies and various metal species, and through incorporating supramolecular assemblies and various metal species and their conjugates. Substantial advancements of these innovative colloidal inorganic nanocontainers drive researchers in promoting them toward innovative applications like stimuli (light/ultrasound/magnetic)-responsive delivery-associated therapies with exceptional performance in vivo. Here, a brief overview of the fabrication of siliceous frameworks, along with discussions on the significant advances in engineering of MSNs, is provided. The scope of the advancement in terms of structural and physicochemical attributes and their effects on biomedical applications with a particular focus on recent studies is emphasized. Finally, interesting perspectives are recapitulated, along with the scope toward clinical translation. 相似文献
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含纳米银的明胶/壳聚糖纳米纤维的制备及其抗菌性能研究 总被引：2，自引：0，他引：2
以浓度为88%的甲酸溶液作为纺丝溶剂,采用静电纺丝和紫外光照射还原的方法制备了含纳米银颗粒的明胶/壳聚糖纳米纤维。研究发现,壳聚糖的加入量低于明胶质量的3/16时可以得到纳米纤维,纤维平均直径随着硝酸银加入量的增大而减小,纤维表面纳米银的平均直径随着硝酸银加入量的增大而增大,在纺丝体系中硝酸银的加入量存在一个极限值。所制得含纳米银的明胶/壳聚糖纳米纤维对金黄色葡萄球菌和绿脓杆菌具有较好的抑菌性能,纺丝时加入1%硝酸银制得纳米纤维膜的抑菌率达到99%以上,这种抗菌型纳米纤维可以应用于医用敷料等领域。 相似文献
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Metal nanoparticles (NPs) are frequently encountered in daily life, and concerns have been raised about their toxicity and safety. Among which, they naturally accumulate in the liver after introduction into the body, independent of the route of administration. Some NPs exhibit intrinsic pharmaceutical effects that are related to their physical parameters, and their inadvertent accumulation in the liver can exert strong effects on liver function and structure. Even as such physiological consequences are often categorically dismissed as toxic and deleterious, there are cell type‐specific and NP‐specific biological responses that elicit distinctive pharmacological consequences that can be harnessed for good. By limiting the scope of discussion to metallic NPs, this work attempts to provide a balanced perspective on their safety in the liver, and discusses both possible therapeutic benefits and potential accidental liver damage arising from their interaction with specific parenchymal and nonparenchymal cell types in the liver. 相似文献
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《Advanced Materials Interfaces》2018,5(7)
Intercalation in bulk layered materials has been investigated intensively in the last 60 years. However, the rise of 2D few‐layered nanomaterials such as transition metal oxides and chalcogenides opened up thrilling opportunities for the new era of intercalation as it is almost guaranteed that new phenomena will be observed with the intercalation of ions and molecules into few‐layered nanomaterials due to the quantum confinement effect at the 2D scale. In this progress report, the advances of the 2D intercalation chemistry in the few‐layered oxides and chalcogenides of molybdenum and tungsten are highlighted with respect to its concept, structure, implementation, identification, property modulation, and applications. The perspective and outlook concerning its current obstacles and future opportunities are addressed. The 2D intercalation chemistry in few‐layered nanomaterials is still under its infant stage. The new intercalation phenomena behind the interlayer engineering of few‐layered nanomaterials need to be discovered and further comprehensively exploited. It is strongly believed that with more attentions and efforts put into this spring field, the few‐layered 2D nanomaterials will make great impact on the nanoscience and nanotechnology, enabling them more profound than their microstructural counterparts and even their monolayers. 相似文献
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Ji-Soo Jang Jun Kyu Kim Kyeounghak Kim Wan-Gil Jung Chaesung Lim Sangwoo Kim Dong-Ha Kim Bong-Joong Kim Jeong Woo Han WooChul Jung Il-Doo Kim 《Advanced materials (Deerfield Beach, Fla.)》2020,32(46):2003983
The ex-solution phenomenon, a central platform for growing metal nanoparticles on the surface of host oxides in real time with high durability and a fine distribution, has recently been applied to various scientific and industrial fields, such as catalysis, sensing, and renewable energy. However, the high-temperature processing required for ex-solutions (>700 °C) limits the applicable material compositions and has hindered advances in this technique. Here, an unprecedented approach is reported for low-temperature particle ex-solution on important nanoscale binary oxides. WO3 with a nanosheet structure is selected as the parent oxide, and Ir serves as the active metal species that produces the ex-solved metallic particles. Importantly, Ir doping facilitates a phase transition in the WO3 bulk lattice, which further promotes Ir ex-solution at the oxide surface and eventually enables the formation of Ir particles (<3 nm) at temperatures as low as 300 °C. Low-temperature ex-solution effectively inhibits the agglomeration of WO3 sheets while maintaining well-dispersed ex-solved particles. Furthermore, the Ir-decorated WO3 sheets show excellent durability and H2S selectivity when used as sensing materials, suggesting that this is a generalizable synthetic strategy for preparing highly robust heterogeneous catalysts for a variety of applications. 相似文献
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Redel E Petrov S Dag O Moir J Huai C Mirtchev P Ozin GA 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(1):68-72
A universal, simple, robust, widely applicable and cost-effective aqueous process is described for a controlled oxidative dissolution process of micrometer-sized metal powders to form high-purity aqueous dispersions of colloidally stable 3-8 nm metal oxide nanoparticles. Their utilization for making single and multilayer optically transparent high-surface-area nanoporous films is demonstrated. This facile synthesis is anticipated to find numerous applications in materials science, engineering, and nanomedicine. 相似文献