Chiral inorganic nanostructures for theranostics

Inorganic chiral nanomaterials have attracted wide attention because of their superior physical properties and chiroptical activities. Great progress in chiral nanostructure preparation has been made, such as noble metals and semiconductors. In this review, we introduce several chiral nanomaterials with feasible biocompatibility and low cytotoxicity that are promising candidates for biological applications, and we focus on their preparation in terms of their circular dichroism (CD) effects and circular luminescence properties. Additionally, we summarize the working function of chiral nanostructures toward some common diseases with high prevalence, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), diabetes and even cancers. The introduction of inorganic chirality will provide a novel way to diagnose and treat these diseases.     

A brief review of graphene-based material synthesis and its application in environmental pollution management

Graphene is an interesting two-dimensional carbon allotrope that has attracted considerable research interest because of its unique structure and physicochemical properties. Studies have been conducted on graphene-based nanomaterials including modified graphene, graphene/semiconductor hybrids, graphene/metal nanoparticle composites, and graphene-complex oxide composites. These nanomaterials inherit the unique properties of graphene, and the addition of functional groups or the nanoparticle composites on their surfaces improves their performance. Applications of these materials in pollutant removal and environmental remediation have been explored. From the viewpoint of environmental chemistry and materials, this paper reviews recent important advances in synthesis of graphene-related materials and their application in treatment of environmental pollution. The roles of graphene-based materials in pollutant removal and potential research are discussed.     

Boosting charge collection efficiency via large-area free-standing Ag/ZnO core-shell nanowire array electrodes

Hybrid nanostructures, comprising of a metal core and a semiconductor shell layer, show great potential for a new generation of low-cost solar cells due to their unique electronic and optical properties. However, experimental results have fallen far short of the ultra-high efficiency(i.e. beyond Shockley-Queisser limit) predicted by theoretical simulations. This limits the commercial application of these materials. Here, a non-transparent organic solar cell with an array of Ag/ZnO nanowires has been experimentally fabricated to increase the internal quantum efficiency(IQE) by a factor of 2.5 compared to a planar counterpart. This result indicates a significant enhancement of charge collection efficiency due to the ultrafast Ag nanowire channels. This hybrid nanostructure can also serve as a perfect back reflector for semi-transparent solar cells, which can result in enhanced light absorption by a factor of 1.8 compared to the reference samples. The enhanced charge collection and light absorption can make these Ag/ZnO nanostructures available for the application of modern optoelectronic devices.     

Non-symmetric hybrids of noble metal-semiconductor: Interplay of nanoparticles and nanostructures in formation dynamics and plasmonic applications

Noble metal-semiconductor hybrids have been employed as fundamental structures in modern technologies. In these hybrids, their cooperative multiple functions attract much attention in recent years because of the interplay of nanoparticles and nanostructures. In this review, we summarize the interplay of nanoparticles and nanostructures in specific kinds of noble metal-semiconductor hybrids, termed as non-symmetric hybrids of noble metal-semiconductor. It particularly refers to metal nanoparticles (or semiconducting quantum dots) at 1-dimensinal (1D) and 2-dimensional (2D) semiconductor (or metal) nanostructures, in contrast to the core/shell and heterodimer nanostructures. First, we discuss the formation dynamics, especially in chemical growth and assembly as well as physical coating and deposition, of non-symmetric noble metal-semiconductor hybrids with nanoparticles on nanostructures. Second, we introduce the plasmon-related applications of these hybrids in heterogeneous catalysis, optoelectronic or photovoltaic devices, all-optical devices, and surface detection or modulation. This review not only provides a comprehensive understanding of the formation mechanisms of the non-symmetric metal-semiconductor hybrid nanostructures, but also may inspire new ideas of novel functional devices and applications based on these systems.     

Insights to Advanced Inorganic Nanoparticles,Nanorods,Nanofibers and Nanotubes:Preparation and Applications

1 Results Quasi one-dimensional nanostructured materials have received considerable attention due to their unique optical and electrical properties and potential applications in nanodevices.Much effort has been directed toward exploring novel synthetic methods and understanding the chemical and physical properties of these nanostructures.The chemical vapor deposition and thermal evaporation,are proved to be efficient for the preparation of wirelike nanomaterials,however these methods are quite energy co...     

Self-assembly of chiral amphiphiles with π-conjugated tectons

Self-assembly of chiral amphiphiles with π-conjugated tectons into one-dimensional helical nanostructures offers great potential applications in the biological,physical,and material sciences.In this review,the recent development of supramolecular self-assembly of chiral amphiphiles with π-conjugated tectons has been discussed on the basis of experimental exploration by elegantly utilizing cooperative noncovalent forces such as π-π stacking,hydrophobic interaction,hydrogen bond and electrostatic interaction,and the potential applications of these self-assembled helical nanostructures in chiral recognition,asymmetric catalysis,electrical conduction,switchable interfaces and soft template for the fabrication of one-dimensional hard materials are described by a representative example.Meanwhile,some scientific and technical challenges in the development of supramolecular self-assembly of chiral amphiphiles with π-conjugated tectons are also presented.It is hoped that this review can summarize the strategies for self-assembling soft nanomaterials by using chiral amphiphiles with π-conjugated tectons,and also as a guideline for design functional nanomaterials for various potential applications.     

Improved ethanol, acetone and H2 sensing performances of micro-sensors based on loose ZnO nanofibers

Both one-dimensional nanostructures and porous nanostructures are benefit to the sensing enhancement of semiconducting functional materials.The present paper shows an effective route to combining the advantages of these two nanostructures for a novel type of ZnO nanomaterials.Basically,a pore-forming material is employed in an electrospinning method,and the products are characterized by X-ray powder diffraction(XRD),energy dispersive X-ray spectroscopy(EDX),and transmission electron microscopy(TEM).The obtained materials are loose ZnO nanofibers,which own both porous and one-dimensional nanostructures.Micro-sensors are fabricated by sputtering and etching techniques,and the as-prepared nanofibers are used as the functional materials in them.The sensors show improved sensing properties both in sensitivity and response-speeds.The sensitivity is enhanced from 4 to 8 and the response time is shortened from 14 to 10 s when the sensors are exposed to 100 μL/L ethanol at 260℃.Similar results are also observed in acetone and H2 sensing tests.These enhancements are based on the one-dimensional and porous nanostructures of the nanofibers.     

Research progress in ZnO single-crystal: growth,scientific understanding,and device applications

Zinc oxide, a wide band-gap semiconductor, has shown extensive potential applications in high-efficiency semiconductor photoelectronic devices, semiconductor photocatalysis, and diluted magnetic semiconductors. Due to the undisputed lattice integrity, ZnO single crystals are essential for the fabrication of high-quality ZnO-based photoelectronic devices, and also believed to be ideal research subjects for understanding the underlying mechanisms of semiconductor photocatalysis and diluted magnetic semiconductors. This review, which is organized in two main parts, introduces the recent progress in growth, basic characterization, and device development of ZnO single crystals, and some related works in our group. The first part begins from the growth of ZnO single crystal, and summarizes the fundamental and applied investigations based on ZnO single crystals. These works are composed of the fabrication of homoepitaxial ZnO-based photoelectronic devices, the research on the photocatalysis mechanism, and dilute magnetic mechanism. The second part describes the fabrication of highly thermostable n-type ZnO with high mobility and high electron concentration through intentional doping. More importantly, in this part, a conceptual approach for fabricating highly thermostable p-type ZnO materials with high mobility through an integrated three-step treatment is proposed on the basis of the preliminary research.     

固浸透镜技术的研究与最新进展

固浸透镜技术自1990年提出以来,不断地发展趋于成熟。现主要介绍固浸透镜技术的基本原理和近年来固浸透镜技术在各个领域的研究成果以及最新的进展情况。总结了该技术在近场光学存储、半导体纳米结构研究、固浸显微镜等领域内的应用。未来固浸透镜技术具有极好的应用前景。     

特殊形貌纳米氧化锌的吸波性能研究

纳米ZnO作为一种新型吸波材料受到广泛关注,但对非c轴生长的ZnO纳米结构材料的吸波性能还缺乏系统研究.为了探讨ZnO纳米晶体的形貌对其吸波性能的影响,在熔盐、类离子液体等强极性介质中,合成了枝晶状、片状、锥状等非c轴生长的ZnO纳米结构材料,用XRD、SEM、TEM等对其物相、形貌进行了表征,对不同形貌的ZnO纳米结构材料的电磁性能与吸波性能进行了系统的分析,并与商品ZnO微粉的吸波性能进行了比较.结果表明,ZnO纳米片的吸波效果较好.复合了磁性材料后,ZnO的吸波性能有明显提高.     

铝片衬底上氧化锌纳米结构的水热合成

以氯化锌溶液和氨水为原料,采用水热合成方法,在铝片衬底上制备出多种氧化锌纳米结构.X射线衍射和扫描电镜分析结果表明:铝衬底上的氧化锌为纤锌矿结构,所得氧化锌结构包括六边形片状结构叠合而成的花形、棒状、管状结构等.随着反应时间的增加,产物中会同时出现大量棒状及管状氧化锌;pH值对氧化锌纳米结构的尺寸、形貌有较大的影响.     

中孔Ag微米盘/ZnO纳米棒阵列异质结的构筑及光催化研究

利用简单的两步合成法制备得到新颖的中孔Ag微米盘（HMDs）/ZnO纳米棒（NRs）异质结,主要包括上晶种和异质外延生长.通过简单的合成参数调控,可以制备不同纳米直径、不同长度、不同形状的ZnO NRs,进而制成不同形貌的Ag/ZnO异质结.结构新颖的Ag/ZnO异质结由一维（1D）半导体和二维（2D）纳米结构元构成,Ag/ZnO异质结具有高比表面积和开放的空间结构,在光电领域具有很重要的应用潜力.在光催化测试中,Ag/ZnO异质结表现出优越的催化活性,主要归因于结构独特的Ag/ZnO异质结的协同效应.     

Probing the properties of individual nanostructures by novel techniques

Nanomaterials are the fundamental components of nanoscience and nanotechnology, and they are different from bulk materials in grain size, surface/interface-to-volume ratio and grain shape, which are the origins of their unique electrical, optical, thermodynamic, mechanical and chemical properties. The small size of nanostructures hampers the applications of well-established testing and measurement techniques, thus new methods and approaches must be developed for their synthesis, property characterization and device fabrication. This has been the focus of our research, aiming at exploring state-of-the-art techniques for materials processing and characterization. This paper reviews our progress in nanomaterials research.     

柱状和蝌蚪状ZnO纳米结构的制备方法研究

本研究中采用直接蒸发锌粉的方法,在硅基底上制备了ZnO纳米结构。实验结果表明,温度条件分别为550℃和n600℃时可以得到ZnO纳米柱和ZnO纳米蝌蚪。Raman光谱分析知,所得的两种ZnO结构均为六角纤锌矿结构。实验中制备的纳米结构的纯度很低,缺陷很少。     

Nanostructured ZnO for biosensing applications

Based on the unique properties, nanostructured ZnO could provide a stable immobilization for biomolecules retaining their biological activity. It has been recently developed as a nice candidate for the construction of biosensors with enhanced analytical performance. In this paper, we reviewed the progress in adapting nanostructured ZnO for several predominantly in biosensing applications based on enzymic reaction, immunoreaction, and molecular compitation. We also described several important considerations when working with nanostructured ZnO mainly centered on the fabrications of ZnO and appropriate strategies for biosensor construction (e.g. modified electrodes and multilayered immobilization).     

图案化氧化锌在能源器件中的应用

ZnO作为一种典型的直接带隙宽禁带半导体材料极具开发潜力和应用价值.随着图案化技术的不断发展优化,ZnO纳米棒阵列的精确可控制备逐步得到实现.本文综述了利用激光限域技术制备图案化ZnO纳米棒阵列的方法,并详述了其在太阳能电池和光电化学电池中的应用.激光干涉法制备的ZnO纳米阵列比表面积大且具有直线传输的优势,运用于光伏器件和电化学电池中增加了光吸收同时利于载流子传输,器件性能显著提高.图案化ZnO纳米棒阵列具有可控的三维空间结构,广泛应用关于各类能源器件中,具有极大的研究和应用价值.     

铋基纳米材料在肿瘤诊治和抗菌中的应用进展

随着纳米技术的快速发展,纳米材料作为新型生物材料在生物医学领域表现出独特的优势,受到研究人员的广泛关注。铋基纳米材料因其良好的生物相容性和优异的光学等物理化学特性,在肿瘤诊治和抗菌等生物医学领域的应用已被广泛研究和报道,并展现出广阔的应用前景。简要综述了生物医用铋基纳米材料在计算机断层扫描成像、光声成像等生物成像和光动力治疗、放射治疗、光热治疗等肿瘤治疗以及抗菌中的研究进展,希望为铋基纳米材料在生物医学领域中的应用提供帮助。     

固定化金属离子亲和色谱研究进展

 固定化金属离子亲和色谱是将过渡金属离子通过配体螯合在固相基质上,通过过渡金属离子与靶分子的组氨酸或半胱氨酸特异性结合形成相对稳定的复合物,最后以竞争性洗脱方式实现靶分子的富集与纯化,其核心为金属螯合亲和基质材料制备。具有亲和选择性高、生物兼容性好、可逆再生等优势,迄今已发展了40余年,广泛应用于靶分子的特异性富集、分离与纯化,本文综述了近3年固定化金属离子亲和色谱纳米材料、微球色谱基质、棉纤维、分子印迹材料、整体材料、共价有机骨架等方面的研究进展。     

Single-nanowire electrically driven lasers

Electrically driven semiconductor lasers are used in technologies ranging from telecommunications and information storage to medical diagnostics and therapeutics. The success of this class of lasers is due in part to well-developed planar semiconductor growth and processing, which enables reproducible fabrication of integrated, electrically driven devices. Yet this approach to device fabrication is also costly and difficult to integrate directly with other technologies such as silicon microelectronics. To overcome these issues for future applications, there has been considerable interest in using organic molecules, polymers, and inorganic nanostructures for lasers, because these materials can be fashioned into devices by chemical processing. Indeed, amplified stimulated emission and lasing have been reported for optically pumped organic systems and, more recently, inorganic nanocrystals and nanowires. However, electrically driven lasing, which is required in most applications, has met with several difficulties in organic systems, and has not been addressed for assembled nanocrystals or nanowires. Here we investigate the feasibility of achieving electrically driven lasing from individual nanowires. Optical and electrical measurements made on single-crystal cadmium sulphide nanowires show that these structures can function as Fabry-Perot optical cavities with mode spacing inversely related to the nanowire length. Investigations of optical and electrical pumping further indicate a threshold for lasing as characterized by optical modes with instrument-limited linewidths. Electrically driven nanowire lasers, which might be assembled in arrays capable of emitting a wide range of colours, could improve existing applications and suggest new opportunities.     

ZnO微纳米结构的制备及其光学性能

在没有催化剂的情况下,空气中直接加热氧化锌片成功制备出ZnO纳米线/纳米片.通过改变反应温度,分别能够获得紧密排列的ZnO纳米线和纳米片.ZnO纳米线和纳米片的直径为几个微米,厚度约为280 nm.室温光致发光测试研究表明其最大可见发射波长在508 nm.该研究工作为纳米器件研制提供了一种简单直接氧化方法,可望高产率制备高质量半导体纳米线和纳米片阵列.