功能材料化合物——瓜环的应用研究进展

瓜环是一种极具广阔应用前景的新型功能材料化合物.综述了瓜环的应用研究现状,重点讨论了瓜环与金属离子或金属离子配合物作用、瓜环与气体分子及有机分子作用、瓜环的自组装及分子识别作用、瓜环的催化作用等,指出寻找一种快速简便的制备和分离技术是瓜环得到广泛应用的关键.     

检测金属离子的R-S-F结构型荧光分子传感器研究进展

Receptor-Spacer-Fluorophore(R-S-F)结构型荧光分子传感器是由可选择性结合客体的主体基团与传递信号的荧光团通过桥联基团连接而成的一类分子传感器,结合了超分子在分子识别中良好的选择性和荧光信号的高灵敏度两个优点,成为一类可用于检测金属离子并具巨大发展潜力的新型光学敏感材料.以超分子主体化合物...     

基于杯吡咯及其衍生物的化学传感器研究进展

杯吡咯是近年来一类新兴的超分子主体化合物,由于其独特的结构和理化性质,使得杯吡咯及其衍生物在识别金属离子、阴离子和中性小分子方面应用广泛。通过引入不同基团、改变其空腔大小得到的主体可以与不同大小、不同性质的客体分子相匹配,可作为敏感材料应用于离子选择电极、离子敏感场效应管、压电晶体、离子光导膜等多种类型的化学传感器上,对各种阴离子和中性分子的识别和检测。     

基于碳量子点的分子印迹荧光检测体系研究进展

复杂基质中痕量分析物的高选择性和高灵敏度检测对环境保护和食品安全等问题具有重要意义。近年来,色谱法等传统检测方法可达到高灵敏度检测的需求,但在选择性、样品预处理过程、维护费用等方面不同程度地存在欠缺,因此迫切需要寻求一种兼具高灵敏度和高选择性,且成本低廉、简便快速的检测手段。将碳量子点(carbon quantum dots, CQDs)的荧光检测与分子印迹材料(molecularly imprinted polymers, MIPs)的分子识别耦合起来,构建高效的碳量子点分子印迹(CQDs-MIPs)荧光检测体系,合成路线简单、成本低廉,对目标物质的检测具有高灵敏度、高选择性和强的抗干扰能力,将会在复杂基质中极低浓度物质的检测方面发挥重要作用。MIPs具有与目标分子高度匹配的识别位点,可实现对目标分子的选择性识别和富集;CQDs作为一种新型的碳基纳米荧光材料,具有优异的光学特性、良好的水溶性和生物相容性,且绿色环保、无毒无害,对目标分子的高灵敏荧光响应使它在荧光检测领域具备不可替代的优势。综述了CQDs-MIPs检测体系的构建策略和工作机理,以及近年来在环境、食品和临床领域的应用进展...     

基于苯并噻唑类螺吡喃检测三价金属离子铁、铬、铝的比色和荧光化学传感器

合成了新型苯并噻唑类的螺吡喃化合物3-苄基-8′-甲氧基-6′-硝基-3H-螺[苯并[d]噻唑-2,2′-苯并吡喃]即SP,其可以作为比色和荧光化学传感器,用来检测溶液中的三价金属离子铁、铬和铝。由于苯并噻唑类螺吡喃化合物特殊的结构与性能,在不同的光照条件下此化合物SP可以作为重要的光响应分子。采用紫外-可见分光光度计、荧光-分光光度计、傅里叶红外光谱仪和核磁共振仪分析了化合物的性能。结果表明:此化合物具有良好的裸眼识别效果、紫外和荧光识别效果,良好的抗干扰性,较快的响应时间和较低的检测限等优点。     

新型纳米多孔材料——金属有机配位聚合物的包结作用及其应用研究进展

金属有机配位聚合物(MOCPs)具有纳米多孔的特殊结构,且结构具有可设计性,通过MOCPs活性位点与客体分子的包结作用能够选择性地包结多种客体分子,表现出特有的分子识别能力.MOCPs作为一种新型多孔材料在择形及手性催化、吸附分离、气体储存、分子识别与传感、生物模拟、微反应器等研究应用方面具有诱人的潜力.综述了MOCPs的设计、合成及主-客体相互作用方式,并展望了这种聚合物的应用前景.     

瓜环与四苯基卟啉锌的功能组装

采用紫外-可见吸收光谱(UV-Vis)、红外光谱(IR)、扫描电镜(SEM)技术探讨了瓜环Q[7,8]与具有光动力疗效的光敏剂四苯基卟啉锌(Zn TPP)分子之间的组装作用。结果表明,Q[7,8]与Zn TPP均形成以1∶1为主的组装物;溶液p H值在5.0~11.0范围内,组装体较稳定;主-客体间的相互作用都能够自发进行,组装过程是放热反应,以熵驱动为主;与Zn TPP相比,组装体的荧光量子产率并没有明显下降;Zn TPP与Q[7,8]组装后,溶解度得到极大的提高。     

金属纳米团簇强荧光研究获进展

正近日,安徽大学和美国卡内基梅隆大学、匹兹堡大学合作完成的一项研究,使人类有望开发出新一代生物荧光检测与诊断试剂,为进一步了解金属纳米团簇的荧光起源提供了新思路和方法。相关成果在线发表于《德国应用化学》杂志。众所周知,因为有光,人们可以看到宏观世界的美妙;因为荧光,科研工作者可以看到微观世界的细胞精细结构,甚至可以在分子层面了解化学反应。     

荧光发色团插层镁铝水滑石的制备和光物理性质

以层状镁铝水滑石[Mg 0.66 Al 0.34(OH)2](CO3)0.17.0.67H2O为主体,通过离子交换法,分别将乙基橙(EO-)和4-氨基偶氮苯基-4-磺酸阴离子(4A-)插入到层状镁铝水滑石层间和吸附在镁铝水滑石表面.插层产物及表面吸附产物分别采用XRD、IR、TG-DTA等测试技术进行结构表征,采用UV-Vis吸收光谱和荧光光谱研究其光谱特征.并用G03w软件包中ab initio分子轨道法(HF/6-31G)计算了客体分子结构和电荷分布,认为客体阴离子以单层形式垂直排布于层板之间.结果表明,客体进入层间后,由于客体与主体的相互作用,在限域空间内客体微环境的改变造成荧光发射强度发生改变,与纯客体相比EO插层产物的荧光强度提高,而4A插层产物的荧光发射强度却大大减弱,EO与4A的吸附产物荧光发射强度均降低,说明通过主体与客体或客体与客体的相互作用可以改变客体的光物理性质.     

共价有机框架和荧光分子的一体化自组装对神经毒模拟物的超灵敏检测

荧光分子通过非共价键作用载入到多孔矩阵中能够拓展其应用范围.本文报道了利用乳液限域的方法将带有苯并噻二唑和9,9-二己基芴基团的荧光分子1和共价有机框架(Covalent Organic Frameworks, COFs)一体化自组装,使得分子1通过CH-π作用固定在共价有机框架的骨架之上.因此这会极大地抑制荧光分子之间的π-π作用,使其表现出荧光分子单体的光学性质.更有意思的是,共价有机框架和神经毒剂模拟物(DCP)的特殊的作用,使得一体化自组装的复合物能够实现对神经毒剂模拟物高灵敏度的检测(检测限为40 ppb).而且,当前的一体化组装策略能够被拓展用于装载多种不同发射波长的荧光分子来实现白光.我们的结果提供了一种利用荧光探针分子和共价有机框架综合自组装来制备高发光效率多孔材料的新方法.     

Gas detection by structural variations of fluorescent guest molecules in a flexible porous coordination polymer

The development of a new methodology for visualizing and detecting gases is imperative for various applications. Here, we report a novel strategy in which gas molecules are detected by signals from a reporter guest that can read out a host structural transformation. A composite between a flexible porous coordination polymer and fluorescent reporter distyrylbenzene (DSB) selectively adsorbed CO? over other atmospheric gases. This adsorption induced a host transformation, which was accompanied by conformational variations of the included DSB. This read-out process resulted in a critical change in DSB fluorescence at a specific threshold pressure. The composite shows different fluorescence responses to CO? and acetylene, compounds that have similar physicochemical properties. Our system showed, for the first time, that fluorescent molecules can detect gases without any chemical interaction or energy transfer. The host-guest coupled transformations play a pivotal role in converting the gas adsorption events into detectable output signals.     

Supramolecular-Macrocycle-Based Crystalline Organic Materials

Supramolecular macrocycles are well known as guest receptors in supramolecular chemistry, especially host−guest chemistry. In addition to their wide applications in host−guest chemistry and related areas, macrocycles have also been employed to construct crystalline organic materials (COMs) owing to their particular structures that combine both rigidity and adaptivity. There are two main types of supramolecular-macrocycle-based COMs: those constructed from macrocycles themselves and those prepared from macrocycles with other organic linkers. This review summarizes recent developments in supramolecular-macrocycle-based COMs, which are categorized by various types of macrocycles, including cyclodextrins, calixarenes, resorcinarenes, pyrogalloarenes, cucurbiturils, pillararenes, and others. Effort is made to focus on the structures of supramolecular-macrocycle-based COMs and their structure–function relationships. In addition, the application of supramolecular-macrocycle-based COMs in gas storage or separation, molecular separation, solid-state electrolytes, proton conduction, iodine capture, water or environmental treatment, etc., are also presented. Finally, perspectives and future challenges in the field of supramolecular-macrocycle-based COMs are discussed.     

Molecular printboards on silicon oxide: lithographic patterning of cyclodextrin monolayers with multivalent, fluorescent guest molecules

Three compounds bearing multiple adamantyl guest moieties and a fluorescent dye have been synthesized for the supramolecular patterning of beta-cyclodextrin (CD) host monolayers on silicon oxide using microcontact printing and dip-pen nanolithography. Patterns created on monolayers on glass were viewed by laser scanning confocal microscopy. Semi-quantitative analysis of the patterns showed that with microcontact printing approximately a single monolayer of guest molecules is transferred. Exposure to different rinsing procedures showed the stability of the patterns to be governed by specific supramolecular multivalent interactions. Patterns of the guest molecules created at CD monolayers were stable towards thorough rinsing with water, whereas similar patterns created on poly(ethylene glycol) (PEG) reference monolayers were instantly removed. The patterns on CD monolayers displayed long-term stability when stored under N(2), whereas patterns at PEG monolayers faded within a few weeks due to the diffusion of fluorescent molecules across the surface. Assemblies at CD monolayers could be mostly removed by rinsing with a concentrated CD solution, demonstrating the reversibility of the methodology. Patterns consisting of different guest molecules were produced by microcontact printing of one guest molecule and specific adsorption of a second guest molecule from solution to non-contacted areas, giving well-defined alternating assemblies. Fluorescent features of sub-micrometer dimensions were written using supramolecular dip-pen nanolithography.     

Effects of molecular shape on the photoluminescence of dyes embedded in a chiral polymer with a photonic band gap

Circularly polarized photoluminescence has been generated by embedding fluorescent guest molecules in a helically aligned polymer host with a selective reflection band, which coincides with the emission wavelength of the embedded dyes. We have investigated the photoluminescence from a range of guest molecules of varying shapes and found that one circular polarization is suppressed within the reflection band of the host independently of the shape of the guest molecules. However, just outside the band edges, there is an enhancement of the same polarization and the relative magnitudes of the enhancement at the two band edges is strongly influenced by the shape of the guest molecules. This effect has been understood from the ordering of the guest molecules in the polymer host.     

Fluorescent cyclodextrin immobilized on a cellulose membrane as a chemosensor system for detecting molecules

Dansyl glutamate-modified cyclodextrin (DnsGlu-beta-CD) was prepared as a fluorescent host, which is capable of being immobilized on a cellulose membrane (DnsGlu-beta-CD-membrane). The fluorescence intensity of DnsGlu-beta-CD decreased with increasing concentration of guest molecules, indicating that the host changes the location of the dansyl group from inside to outside the cyclodextrin cavity upon guest accommodation. Similar guest-induced decrease in the fluorescence intensity was observed for DnsGlu-beta-CD immobilized to a cellulose membrane. This result demonstrates that the cellulose membrane may be used as a practical supporting material of various chromophore-modified cyclodextrins and that DnsGlu-beta-CD-membrane is useful as a novel disposable chemosensor for molecules.     

Recent Advances of Using Hybrid Nanocarriers in Remotely Controlled Therapeutic Delivery

The development of hybrid biomaterials has been attracting great attention in the design of materials for biomedicine. The nanosized level of inorganic and organic or even bioactive components can be combined into a single material by this approach, which has created entirely new advanced compositions with truly unique properties for drug delivery. The recent advances in using hybrid nanovehicles as remotely controlled therapeutic delivery carriers are summarized with respect to different nanostructures, including hybrid host–guest nanoconjugates, micelles, nanogels, core–shell nanoparticles, liposomes, mesoporous silica, and hollow nanoconstructions. In addition, the controlled release of guest molecules from these hybrid nanovehicles in response to various remote stimuli such as alternating magnetic field, near infrared, or ultrasound triggers is further summarized to introduce the different mechanisms of remotely triggered release behavior. Through proper chemical functionalization, the hybrid nanovehicle system can be further endowed with many new properties toward specific biomedical applications.     

Optochemically Responsive 2D Nanosheets of a 3D Metal–Organic Framework Material

Outstanding functional tunability underpinning metal–organic framework (MOF) confers a versatile platform to contrive next‐generation chemical sensors, optoelectronics, energy harvesters, and converters. A rare exemplar of a porous 2D nanosheet material constructed from an extended 3D MOF structure is reported. A rapid supramolecular self‐assembly methodology at ambient conditions to synthesize readily exfoliatable MOF nanosheets, functionalized in situ by adopting the guest@MOF (host) strategy, is developed. Nanoscale confinement of light‐emitting molecules (as functional guest) inside the MOF pores generates unusual combination of optical, electronic, and chemical properties, arising from the strong host–guest coupling effects. Highly promising photonics‐based chemical sensing opened up by the new guest@MOF composite systems is shown. By harnessing host–guest optochemical interactions of functionalized MOF nanosheets, detection of an extensive range of volatile organic compounds and small molecules important for many practical applications has been accomplished.     

Immobilized fluorescent cyclodextrin on a cellulose membrane as a chemosensor for molecule detection

Dansylglycine-modified cyclodextrin (DnsC4-beta-CD) was prepared as a fluorescent host that is capable of being immobilized on a cellulose membrane (DnsC4-beta-CD membrane). DnsC4-beta-CD immobilized on the cellulose membrane decreased its fluorescence intensity with increasing concentration of guest molecules, indicating that the host changes the location of the dansyl group from inside to outside the cyclodextrin cavity upon guest accommodation, which is similar to DnsC4-beta-CD in solution; thereby, the DnsC4-beta-CD membrane is useful as a novel chemosensor for detecting molecules. This result demonstrates that the cellulose membrane is useful as a practical supporting material for various chromophore-modified cyclodextrins.     

Multiplexed Luminescence Oxygen Channeling Immunoassay Based on Dual‐Functional Barcodes with a Host–Guest Structure: A Facile and Robust Suspension Array Platform

The development of a powerful immunoassay platform with capacities of both simplicity and high multiplexing is promising for disease diagnosis. To meet this urgent need, for the first time, a multiplexed luminescent oxygen channeling immunoassay (multi‐LOCI) platform by implementation of LOCI with suspension array technology is reported. As the microcarrier of the platform, a unique dual‐functional barcode with a host–guest structure composed of a quantum dot host bead (QDH) and LOCI acceptor beads (ABs) is designed, in which QDH provides function of high coding capacity while ABs facilitate the LOCI function. The analytes bridge QDH@ABs and LOCI donor beads (DBs) into a close proximity, forming a QDH@ABs–DBs “host–guest–satellite” superstructure that generates both barcode signal from QDH and LOCI signal induced by singlet oxygen channeling between ABs and DBs. Through imaging‐based decoding, different barcodes are automatically distinguished and colocalized with LOCI signals. Importantly, the assay achieves simultaneous detection of multiple analytes within one reaction, simply by following a “mix‐and‐measure” protocol without the need for tedious washing steps. Furthermore, the multi‐LOCI platform is validated for real sample measurements. With the advantages of robustness, simplicity, and high multiplexing, the platform holds great potential for the development of point‐of‐care diagnostics.     

Materials Nanoarchitectonics Using 2D Layered Materials: Recent Developments in the Intercalation Process

Layered inorganic solids as an attractive classification of 2D materials offer material diversity and a wide range of interesting properties. Layered inorganic solids provide an expandable 2D nanospace between each individual layer, the so called interlayer space, to accommodate/arrange guest species such as molecules, nanoparticles, and polymer chains and design unique nanoarchitectures, resulting in the production of intercalation compounds showing different properties in comparison to those of virgin layered materials and guest species. Layered inorganic solids can also be exfoliated to result in nanosheet production. Further ordering of exfoliated nanosheets is also possible via different methods and normally leads to creating soft materials presenting properties and applications different from that of relatively rigid intercalation compounds. Here, the latest studies and up‐to‐date developments on the possible techniques of designing novel types of materials using layered inorganic solids are specifically highlighted.