纳米化学

介绍了纳米结构物质的发展现状, 着重阐述了纳米物质的化学制备方法以及对其化学性质研究的新进展。介绍了纳米物质的可能应用途径, 指出纳米化学的发展对纳米材料的开发和应用具有十分重要的作用。     

生物纳米孔分析技术研究进展

生物纳米孔传感技术因其快速、低成本、无需荧光标记等优点,在化学和生物等诸多研究领域得到广泛应用,已发展成为一种新颖的、独具特色的单分子分析手段。该技术目前主要应用于DNA测序研究,同时在单分子分析领域也取得了令人瞩目的成就。该文简要介绍了生物纳米孔分析技术的原理和生物孔的种类,主要总结了近20年来生物纳米孔在DNA测序和单分子分析中的研究进展并予以了展望。     

石墨烯纳米带的可控制备研究进展

石墨烯纳米带是宽度为纳米尺度的石墨烯条带,根据其边缘构型的不同可以分为锯齿型石墨烯纳米带和扶手型石墨烯纳米带.纳米尺度导致的量子限域效应和边缘构型引起的边缘效应能够调节石墨烯纳米带的电子结构,打开石墨烯的带隙.而且,石墨烯纳米带具有极大的长宽比和极高比例的边缘原子,为通过结构裁剪实现功能定制提供了无限可能.这些几何和电子结构特性使得石墨烯纳米带在电子器件等诸多领域比石墨烯具有更大的应用潜力,因此,石墨烯纳米带的相关研究一直是纳米材料领域的热点.基于此,本综述首先介绍了石墨烯纳米带的结构和性质,全面介绍了石墨烯纳米带的制备方法,相应的制备方法可以分为两部分:(1)自上而下法:通过等离子体、离子束、扫描隧道显微镜和金属纳米颗粒对石墨烯和碳纳米管进行刻蚀和切割,制备石墨烯纳米带.该方法面临最大挑战在于如何提高刻蚀和切割精度.(2)自下而上法:利用含碳前驱体,如有机化合物、碳氢化合物气体以及碳化硅等,制备石墨烯纳米带.该方法利于实现原子精度的结构控制,尤其是化学气相沉积法有望实现低成本、规模化制备.最后展望石墨烯纳米带研究的挑战和前景.我们相信,随着材料和技术的创新发展,石墨烯纳米带必将成为一...     

石墨烯基无机纳米复合材料*

石墨烯(graphene)是近年被发现和合成的一种新型二维平面纳米碳质材料。由于其新奇的物理和化学性质,石墨烯已经成为了备受瞩目的科学新星,是纳米材料领域的一大研究热点。在石墨烯的研究中,基于石墨烯的无机纳米复合材料是石墨烯迈向实际应用的一个重要方向。本文在简要介绍石墨烯的结构、性质和制备方法的基础上,重点就近年来以石墨烯为基体的无机物（主要包括金属和半导体）纳米复合材料的合成和应用作一述评,并对石墨烯基无机纳米复合材料的研究和发展方向作了展望。     

石墨烯表界面化学修饰及其功能调控

石墨烯属于碳纳米材料家族中的一员,是一种单层的二维原子晶体,具有高硬度、高导热性、高载流子迁移率等诸多优良特性,被认为是新一代电子学器件的重要基础材料.近年来我们课题组利用石墨烯的这些优良特性在其表界面化学修饰及其功能调控方面开展了一系列研究工作.我们对石墨烯表界面进行了共价或非共价化学修饰,在一定程度上打开了石墨烯的带隙,并发展了具有传感功能的石墨烯器件.我们还制备了基于石墨烯的纳米电极,发展了新一代分子电子器件的普适性制备方法,实现了单分子器件的功能化.展望未来,以石墨烯为代表的碳基纳米材料将继续在纳电子器件研究领域发挥重要作用.     

基于纳米材料的表面辅助激光解吸离子化质谱研究

基质辅助激光解吸离子化质谱(MALDI-MS)作为一种常规的分析表征方法主要用于生物大分子的分析,如蛋白质、多肽、多糖及核酸等.然而,MALDI-MS中使用的有机小分子基质在低分子量区会产生背景干扰,很难分析小分子量化合物(m/z < 700).最近,基于纳米材料的免有机基质的激光解吸离子化质谱(又称为表面辅助激光解吸离子化质谱,SALDI-MS)有效解决了上述问题.SALDI-MS分析中使用的起到能量转移作用的纳米材料在低分子量区间不会产生背景干扰峰,可以将分析对象由大分子扩展到小分子.另外,SALDI-MS还具有许多其他优点,如样品制备简单、信噪比高、耐盐性好、基底表面信号重复性好及可实现样品的定量分析等,显示了较好的应用前景.本文综述了研究较多的四大类纳米材料在SALDI-MS分析、检测及成像方面的应用,包括碳纳米材料(富勒烯、碳纳米管、石墨烯及氧化石墨烯)、硅纳米材料(多孔硅、硅纳米纤维、硅纳米粒子)、其他材料纳米粒子(包括金属纳米粒子、金属氧化物纳米粒子、无机盐纳米粒子及量子点等)及纳米杂化多孔材料,详细介绍了最近的一些研究进展;并讨论了纳米材料在SALDI-MS应用中的能量转移机理.最后,讨论了该领域未来的研究内容和方向以及亟待研究的重要问题.     

高介电性能石墨烯/聚合物纳米复合材料研究进展

石墨烯作为一种新型二维平面纳米材料,表现出许多优异的物理性质.将石墨烯与聚合物复合,利用其独特的结构及物理性质,有望开发一类具有卓越介电性能的纳米复合电介质材料.本文总结了高介电石墨烯/聚合物纳米复合材料这一研究方向的最新进展,重点介绍了石墨烯提高聚合物基体介电性能的基本理论、石墨烯/聚合物界面对复合电介质性能的影响等,并简要展望了这类材料的发展前景.     

超高真空下纳米石墨烯磁性及调控

纳米石墨烯在磁学上的优异表现开始获得了更多的关注和研究。由于不饱和电子的存在,磁性纳米石墨烯的湿法化学法合成难度提高,借助超高真空下的表面催化,可以精确地实现将设计好的前驱体分子向磁性纳米石墨烯转变。相较于过渡金属的磁性,纳米石墨烯拥有更高的自旋波刚度、更弱的自旋-轨道耦合作用、更为精细的耦合作用、更长的自旋寿命,使其在自旋电子器件以及基础研究领域拥有很高的研究潜力。由于不饱和电子的存在,提高了湿法化学法合成出磁性纳米石墨烯的难度。近年来,借助超高真空下的表面催化,可以精确地实现将设计好的前驱体分子制备成磁性纳米石墨烯。进一步地,可以利用通过针尖操纵以及将磁性纳米石墨烯进行连接形成二聚体或者磁性链来进行磁性调控和研究。本综述结合近几年超高真空下纳米石墨烯的磁性研究,介绍了纳米石墨磁性的产生和利用超高真空扫描隧道显微技术对其结构和磁性的表征,以及在此基础上对纳米石墨烯磁性的磁序调控。     

石墨烯纳米孔的制备及λ-DNA穿孔初步研究

纳米孔测序是有可能实现"$1,000 Genome"目标的技术之一.近年来,研究较多的纳米孔有蛋白质纳米孔和硅基材料的固态纳米孔.蛋白孔寿命比较短,而基于硅基底的固态纳米孔深度显著超过单链DNA相邻碱基的间距,所以,无法实现DNA的单个碱基的分辨.作者用聚焦离子束先制造氮化硅基底,并在该基底上铺设石墨烯,再用聚焦电子束刻蚀石墨烯,获得直径10 nm以下的纳米孔,初步分析了DNA穿越纳米孔时产生的电信号及穿孔噪音,向单层石墨烯纳米孔测序DNA迈出了一步.     

氧化石墨烯/金银纳米粒子复合材料的制备及其SERS效应研究

近年来,氧化石墨烯/金银纳米粒子复合材料由于其优异的表面增强拉曼散射（SERS）性能引起了人们极大的关注,在污染物检测、化学传感和癌症诊断等领域具有重要的应用价值。本文综述了氧化石墨烯片层上修饰金银纳米粒子、氧化石墨烯包覆金银纳米粒子、氧化石墨烯附着在金银纳米粒子层三种氧化石墨烯/金银纳米粒子复合材料的制备方法,对其SERS效应进行了详细介绍。SERS研究表明,结合了金银纳米粒子与氧化石墨烯两种材料各自在SERS研究与应用中的优势,氧化石墨烯/金银纳米粒子复合材料的SERS性能比单纯金银纳米粒子更加优异。氧化石墨烯在其中起到了化学增强、分子富集、钝化保护、荧光猝灭的重要作用。氧化石墨烯/金银纳米粒子复合材料在表面增强拉曼光谱中具有广阔的应用前景。     

Graphene nanopores toward DNA sequencing: a review of experimental aspects

Nanopores for DNA sequencing have drawn much attention due to their potentials to achieve amplification-free, low-cost, and high-throughput analysis of nuclei acids. The material configuration and fabrication of the nanopore has become one important consideration in the nanopore based DNA sequencing research. Among various materials, the newly emerged graphene has brought more opportunities to the development of sequencing technology because of its unique structures and properties. This review mainly focuses on the experimental aspects of graphene nanopore research including the nanopore fabrication methods and processes. Meanwhile, the challenges in the present graphene nanopore research including hydrophobicity, translocation velocity and noise are also addressed and discussed.     

Electrochemical Affinity Sensors Using Field Effect Transducer Devices for Chemical Analysis

The review presents advances and main challenges of the affinity sensors based on field- effect transistors published during the last five years. The different nanomaterial-based field-effect transistors are classified according to the nature of the nanomaterials, beginning by silicon, the “gold-standard” semiconductor, the gallium nitride semiconductor, the organic semiconductors, the silicon nanowires, the inorganic nanomaterials, the carbon nanotubes and the graphene. Due to its exceptional electrical properties, the main works are devoted to graphene. The obtained analytical performances for the detection of biomarkers, of DNA sequences and of miRNA are listed. The relation between the operational conditions - nature of the nanomaterials, procedure of preparation, choice of the receptor molecule, method of immobilization – and the analytical performance are discussed. The perspective of industrialization of these affinity sensors based on field-effect transistors is discussed.     

基于新型纳米传感材料的DNA生物传感器的应用

DNA是构建纳米技术和生物传感技术新设备的良好构建体.DNA生物传感器由于具有灵敏度高、选择性好等特点,近年来获得了飞速发展.研究发现,金属纳米粒子(MNPs)、碳基纳米材料等一系列纳米材料在传感器设计中提高了电化学DNA传感器的传感性能.本文侧重介绍了场效应晶体管、石墨烯、碳纳米管等新型纳米传感材料,以及基于这些材料...     

Application of carbon-based nanomaterials in sample preparation: A review

In this paper, a broad overview on the applications of different carbon-based nanomaterials, including nanodiamonds, fullerenes, carbon nanotubes, graphene, carbon nanofibers, carbon nanocones-disks and nanohorns, as well as their functionalized forms, in sample preparation is provided. Particular attention has been paid to graphene because many papers regarding its application in this research field are becoming available. The distinctive properties, derivatization methods and application techniques of these materials were summarized and compared. According to their research status and perspective, these nanomaterials were classified in four groups (I: graphene and carbon nanotubes; II: carbon nanofibers; III: fullerenes; and IV: nanodiamonds, carbon nanocones/disks and carbon nanohorns) and characteristics and future trends of every group were discussed.     

Recent trends in carbon nanomaterial-based electrochemical sensors for biomolecules: A review

Carbon nanomaterials are advantageous for electrochemical sensors because they increase the electroactive surface area, enhance electron transfer, and promote adsorption of molecules. Carbon nanotubes (CNTs) have been incorporated into electrochemical sensors for biomolecules and strategies have included the traditional dip coating and drop casting methods, direct growth of CNTs on electrodes and the use of CNT fibers and yarns made exclusively of CNTs. Recent research has also focused on utilizing many new types of carbon nanomaterials beyond CNTs. Forms of graphene are now increasingly popular for sensors including reduced graphene oxide, carbon nanohorns, graphene nanofoams, graphene nanorods, and graphene nanoflowers. In this review, we compare different carbon nanomaterial strategies for creating electrochemical sensors for biomolecules. Analytes covered include neurotransmitters and neurochemicals, such as dopamine, ascorbic acid, and serotonin; hydrogen peroxide; proteins, such as biomarkers; and DNA. The review also addresses enzyme-based electrodes that are used to detect non-electroactive species such as glucose, alcohols, and proteins. Finally, we analyze some of the future directions for the field, pointing out gaps in fundamental understanding of electron transfer to carbon nanomaterials and the need for more practical implementation of sensors.     

The art of two-dimensional soft nanomaterials

The discovery of graphene has triggered the explosive development of two-dimensional(2D) nanomaterials, including both inorganic and organic species. Benefiting from the simple elemental composition, inorganic 2D nanomaterials were the center research in the past decade, which has long shadowed the research of 2D organic(or soft) nanomaterials. Although many kinds of2D soft nanomaterials have been successfully prepared, a unified definition for them is still impossible due to the complicate and quite different chemical structures between each other and even relying on totally different techniques to distinguish them. Since our first review on 2D soft nanomaterials in 2015, this field has moved forward with big success. In this review, we will focus on the development of 2D soft nanomaterials after 2015. In order to deliver better overview of this field, new and comprehensive classification is used in this review: 2D aromatic molecules, graphene and graphene nanoribbons, graphyne and graphdiyne,BxCyNznanosheets, 2D polymers, 2D supramolecules, crystalline 2D assemblies, 2D covalent organic frameworks, 2D metalorganic frameworks, sandwich-like 2D porous polymers, 2D polymer nanosheets, etc. The focus of this review lies on synthetic strategies and the challenges of characterization, definition and fundamental understanding.     

电化学葡萄糖传感器

作为电化学生物传感器中最重要的研究内容之一,葡萄糖生物传感器在数十年的发展中取得了巨大进展。本文综述了近年来利用纳米技术设计的新型电化学葡萄糖传感器的主要研究进展,并从纳米材料维度分类进行了讨论。其中,零维纳米材料主要讨论了包括金纳米颗粒、银纳米颗粒以及铜、铂等金属纳米颗粒材料; 一维纳米材料主要讨论了通过模板法制备的金属或金属氧化物纳米线以及单臂或者多壁纳米管材料; 二维纳米材料主要总结了以碳为基础的石墨烯材料和一些片状的金属材料。纳米材料对电化学葡萄糖传感器的影响主要集中在生物相容性、增强检测灵敏度、酶的固定等方面。此外,本文也对电化学葡萄糖传感器的今后发展做了展望。     

EMI shielding and dynamic mechanical analysis of graphene oxide-carbon nanotube-acrylonitrile butadiene styrene hybrid composites

Carbon nanomaterials such as carbon nanotubes (CNTs), graphene and their hybrid have been studied extensively. Despite having excellent properties of CNTs and graphene have not yet been fully realized in the polymer composites. During fabrication agglomeration of CNTs and restacking of graphene is a serious concern that results in the degradation of properties of nanomaterials into the final composites. To improve the dispersion of CNTs and restacking graphene, in the present research work, we focused on the hybridization of graphene oxide and CNTs. Multiwalled carbon nanotubes (MWCNTs), functionalized carbon nanotubes (FCNTs), and graphene oxide-carbon nanotubes (GCNTs) reinforced acrylonitrile butadiene styrene (ABS) composites were prepared separately by vacuum filtration followed by hot compression molding. Further, dynamic mechanical analysis (DMA), and electromagnetic interference (EMI) shielding properties of ABS composites reinforced carbon nanofillers were investigated. The dynamic mechanical properties of polymers strongly depend on the adhesion of fillers and polymer, entanglement density of polymer chains in the presence of carbon fillers. The dynamic mechanical characteristics such as storage, loss modulus, and damping factor of prepared composites were significantly affected by the incorporation of MWCNTs, FCNTs, and GCNTs. Maximum EMI shielding effectiveness of −49.6 dB was achieved for GCNT-ABS composites which were highest compared to MWCNTs-ABS composites (−38.6 dB) and FCNTs-ABS composites (−36.7 dB) in the Ku band (12.4–18 GHz). These results depict the great potential of GCNTs-ABS composites to be used in various applications of efficient heat dissipative EMI shielding materials for electronic devices.     

Ab initio study on the noncovalent adsorption of camptothecin anticancer drug onto graphene, defect modified graphene and graphene oxide

The application of graphene and related nanomaterials like boron nitride (BN) nanosheets, BN-graphene hybrid nanomaterials, and graphene oxide (GO) for adsorption of anticancer chemotherapeutic camptothecin (CPT) along with the effect on electronic properties prior to functionalization and after functionalization has been reported using density functional theory (DFT) calculations. The inclusion of dispersion correction to DFT is instrumental in accounting for van der Waals π–π stacking between CPT and the nanomaterial. The adsorption of CPT exhibits significant strain within the nanosheets and noncovalent adsorption of CPT is thermodynamically favoured onto the nanosheets. In case of GO, surface incorporation of functional groups result in significant crumpling along the basal plane and the interaction is basically mediated by H-bonding rather than π–π stacking. Docking studies predict the plausible binding of CPT, CPT functionalized graphene and GO with topoisomerase I (top 1) signifying that CPT interacts through π stacking with AT and GC base pairs of DNA and in presence of nano support, DNA bases preferentially gets bound to the basal plane of graphene and GO rather than the edges. At a theoretical level of understanding, our studies point out the noncovalent interaction of CPT with graphene based nanomaterials and GO for loading and delivery of anticancer chemotherapeutic along with active binding to Top1 protein.     

Nucleic acid functionalized graphene for biosensing

There is immense demand for complex nanoarchitectures based on graphene nanostructures in the fields of biosensing or nanoelectronics. DNA molecules represent the most versatile and programmable recognition element and can provide a unique massive parallel assembly strategy with graphene nanomaterials. Here we demonstrate a facile strategy for covalent linking of single stranded DNA (ssDNA) to graphene using carbodiimide chemistry and apply it to genosensing. Since graphenes can be prepared by different methods and can contain various oxygen containing groups, we thoroughly investigated the utility of four different chemically modified graphenes for functionalization by ssDNA. The materials were characterized in detail and the different DNA functionalized graphene platforms were then employed for the detection of DNA hybridization and DNA polymorphism by using impedimetric methods. We believe that our findings are very important for the development of novel devices that can be used as alternatives to classical techniques for sensitive and fast DNA analysis. In addition, covalent functionalization of graphene with ssDNA is expected to have broad implications, from biosensing to nanoelectronics and directed, DNA programmable, self-assembly.