Supramolecular optical sensor arrays for on-site analytical devices

Supramolecular optical chemosensors are useful tools in analytical chemistry for the visualization of molecular recognition information. One advantage is that they can be utilized for array systems to detect multiple analytes. However, chemosensor arrays have been evaluated mainly in the solution phase, which limits a wide range of practical applications. Thus, appropriate solid support materials such as polymer gels and papers are required to broaden the scope of the application of chemosensors as on-site analytical tools. In this review, we summarize the actual approaches for the fabrication of solid-state chemosensor arrays combined with powerful data processing techniques and portable digital recorders for real-world applications.     

Nanoparticle-based assays in automated flow systems: A review

Nanoparticles (NPs) exhibit a number of distinctive and entrancing properties that explain their ever increasing application in analytical chemistry, mainly as chemosensors, signaling tags, catalysts, analytical signal enhancers, reactive species generators, analyte recognition and scavenging/separation entities.     

基于喹啉和三唑环的开链冠醚对金属离子的选择传感

本文通过Click化学反应合成了一种含喹啉基和三唑基的开链冠醚, 考察和比较了主体化合物对镉等金属离子的荧光传感和选择性键合行为, 并通过荧光和核磁等手段研究了溶剂对其荧光传感的影响.     

A supramolecular microfluidic optical chemosensor

A supramolecular microfluidic optical chemosensor (muFOC) has been fabricated. A serpentine channel has been patterned with a sol-gel film that incorporates a cyclodextrin supramolecule modified with a Tb(3+) macrocycle. Bright emission from the Tb(3+) ion is observed upon exposure of the (mu)FOC to biphenyl in aqueous solution. The signal transduction mechanism was elucidated by undertaking steady-state and time-resolved spectroscopic measurements directly on the optical chemosensor patterned within the microfluidic network. The presence of biphenyl in the cyclodextrin receptor site triggers Tb(3+) emission by an absorption-energy transfer-emission process. These results demonstrate that the intricate signal transduction mechanisms of supramolecular optical chemosensors are successfully preserved in microfluidic environments.     

Sensitive and Selective Fluorescent Chemosensors Combining Multiple PET Processes for Ag+ Sensing

In this work, a novel fluorescent chemosensor combining multiple photoinduced electron transfer(PET) processes for the detection of Ag⁺ ion was synthesized. The PET processes were derived from the lone electron pair of the selenium donors and the tertiary nitrogen atom of the coumarin fluorophore, which have not yet been used in the fluorescent chemosensor designed for Ag⁺ ion. Interestingly, the chemosensors showed fluorescent responses to Ag⁺ ion with a fluorescence enhancement factor of 3-5-fold by blocking the intramolecular PET quenching pathways. Furthermore, the probe exhibited high selectivity and sensitivity for Ag⁺ ion over other relevant species with detection limit down to 10 nmol/L level. The chemosensors also showed excellent performances in analyzing natural water samples. The chemosensors developed herein represent a new strategy for the PET fluorescent chemosensor design for the detection of Ag⁺ ion.     

Par-delà la synthèse : l’auto-organisation

The evolution of the universe from the particle to the thinking organism has taken place through self-organization. Chemistry has a major role to play in understanding these processes leading to the generation of complex matter. Chemistry has developed a highly powerful molecular synthetic chemistry, mastering the combination and recombination of atoms into increasingly complex molecules through selective chemical reactions. Supramolecular chemistry is harnessing intermolecular forces for the generation of informed supramolecular systems and processes through supramolecular synthetic chemistry implementing molecular information carried by electromagnetic interactions. Supramolecular chemistry has been actively exploring systems undergoing self-organization, i.e., systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, under the control of interactional molecular recognition events, thus behaving as programmed chemical systems. Molecular chemistry may similarly take advantage of the selectivity of covalent reactions to assemble complex molecular architectures through self-organization processes implementing functional molecular recognition. Supramolecular/non-covalent and molecular/covalent SELF-ORGANIZATION may thus be considered as the ULTIMATE SYNTHETIC CHEMISTRY, whereby chemical objects at both levels are generated on the basis of recognition processes involving either interactional or reactional features. Illustrations from the supramolecular domain will serve as illustrations. Supramolecular entities as well as molecules containing reversible bonds are able to undergo a continuous change in constitution by reorganization and exchange of building blocks. This capability defines a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels. CDC introduces a paradigm shift with respect to constitutionally static chemistry. It takes advantage of dynamic constitutional diversity to allow variation and selection and thus leads towards the emergence of adaptive and evolutive chemistry.     

Driving Forces Controlling Host–Guest Recognition in Supercritical Carbon Dioxide Solvent

The formation of supramolecular host–guest complexes is a very useful and widely employed tool in chemistry. However, supramolecular chemistry in non‐conventional solvents such as supercritical carbon dioxide (scCO₂), one of the most promising sustainable solvents, is still in its infancy. In this work, we explored a successful route to the development of green processes in supercritical CO₂ by combining a theoretical approach with experiments. We were able to synthesize and characterize an inclusion complex between a polar aromatic molecule (benzoic acid) and peracetylated‐β‐cyclodextrin, which is soluble in the supercritical medium. This finding opens the way to wide, environmental friendly, applications of scCO₂ in many areas of chemistry, including supramolecular synthesis, reactivity and catalysis, micro and nano‐particle formation, molecular recognition, as well as enhanced extraction processes with increased selectivity.     

New sensing mechanisms for design of fluorescent chemosensors emerging in recent years

During the past decade, fluorescent chemosensors have become an important research field of supramolecular chemistry and have attracted great attention because of their simplicity, high selectivity and sensitivity in fluorescent assays. In the design of new fluorescent chemosensors, exploration of new sensing mechanisms between recognition and signal reporting units is of continuing interest. Based on different photophysical processes, conventional sensing mechanisms including photo-induced electron transfer (PET), intramolecular charge transfer (ICT), metal-ligand charge transfer (MLCT), twisted intramolecular charge transfer (TICT), electronic energy transfer (EET), fluorescence resonance energy transfer (FRET), and excimer/exciplex formation have been investigated and reviewed extensively in the literature. This tutorial review will mainly focus on new fluorescent sensing mechanisms that have emerged in the past five years, such as aggregation-induced emission (AIE) and C=N isomerization, which can be ascribed to fluorescence changes via conformational restriction. In addition, excited-state intramolecular proton transfer (ESIPT) has not been well reviewed yet, although a number of chemosensors based on the ESIPT mechanism have been reported. Thus, ESIPT-based chemosensors have been also summarized in this review.     

Recent Advances in Luminescent Recognition and Chemosensing of Iodide in Water

This Minireview covers the latest developments of chemosensors based on transition‐metal receptors and organic fluorophores with specific binding sites for the luminescent detection and recognition of iodide in aqueous media and real samples. In all selected examples within the last decade (made‐post 2010), the iodide sensing and recognition is probed by monitoring real‐time changes of the fluorescence or phosphorescence properties of the chemosensors. This review highlights effective strategies to iodide sensing from a structural approach where the iodide recognition/sensing process, through supramolecular interactions as coordination bonds, hydrogen bonds, halogen bonds and electrostatic interactions, is transduced into an optical change easily measurable. The selective iodide sensing is an active field of research with global interest due to the importance of iodide in biological, medicinal, industrial, environmental and chemical processes.     

Recent advances in upper rim functionalization of resorcin[4]arene derivatives: Synthesis and applications

Abstract

During the last decades, resorcin[4]arenes have drawn much attention in the field of supramolecular chemistry because of their practical applicability in different areas. Therefore, many scientists have investigated this class of derivatives in recent years. In this article, we comprehensively reviewed a brief literature survey on the chemistry of upper rim functionalization of calix[4]resorcinarene derivatives and their applications concerning optical chemosensors, liquid crystal materials, host-guest systems, catalysis, drug delivery, biological activities, and analytical applications. This short review describes the survey of literature synthesis and upper rim functionalization of resorcin[4]arenes and their different application published in the last six years (2015–2020).     

Recent progress in the research on the host-guest chemistry of pillar[n]arenes

Pillar[n]arene, as a new kind of macrocyclic host molecule, is a cyclic oligomer, which has a unique rigid structure with a hydrophobic cavity and can interact with many size-matched guest molecules. In this review, the molecular recognition, self-assembly and applications of the pillar[n]arenes in the past two years were described. On the basis of previous scientific research, a variety of pillar[n]arene-based supramolecular systems responsive to specific external stimuli such as pH, redox, gas, light, etc. has been constructed. Pillar[n]arenes have exhibited great potential in constructing these fantastic supramolecular systems based on host-guest recognition, including nanomaterials, controllable drug delivery, transmembrane channels, chemosensors and catalytic entities. These supramolecular systems have a wide range of applications in the material, biology, detection and catalysis field, but their applications are not limited to these fields.     

Cucurbit[10]uril-based chemistry

With the biggest cavity in the cucurbit[n]urils (CB[n]s) family, CB[10] has shown its unique molecular recognition properties. This review gives a brief summary of the research progresses in the CB[10]-based chemistry, involving its purification and applications in fields such as molecular recognition and molecular assembly.     

19F-Labeled Probes for Recognition-Enabled Chromatographic 19F NMR

The NMR technique is among the most powerful analytical methods for molecular structural elucidation, process monitoring, and mechanistic investigations; however, the direct analysis of complex real-world samples is often hampered by crowded NMR spectra that are difficult to interpret. The combination of fluorine chemistry and supramolecular interactions leads to a unique detection method named recognition-enabled chromatographic (REC) ¹⁹F NMR, where interactions between analytes and ¹⁹F-labeled probes are transduced into chromatogram-like ¹⁹F NMR signals of discrete chemical shifts. In this account, we summarize our endeavor to develop novel ¹⁹F-labeled probes tailored for separation-free multicomponent analysis. The strategies to achieve chiral discrimination, sensitivity enhancement, and automated analyte identification will be covered. The account will also provide a detailed discussion of the underlying principles for the design of molecular probes for REC ¹⁹F NMR where appropriate.     

Recent advance of photochromic diarylethenes-containing supramolecular systems

Photochromic diarylethenes were deemed to be one of the most promising molecular building blocks for photoresponsive materials. This review gives a brief summary to the recent progress of studies of diarylethenes in supramolecular systems, focusing on their applications in biological systems, photo-responsive mechanical materials and photo-responsive chemosensors.     

Differential receptor arrays and assays for solution-based molecular recognition

Nature has inspired an emergent supramolecular field of synthetic receptor arrays and assays for the pattern-based recognition of various bioanalytes and metal species. The synthetic receptors are not necessarily selective for a particular analyte, but the combined signal response from the array is diagnostic for the analyte. This tutorial review describes recent work in the literature for this emerging supramolecular field and details basic array and assay design principles. We review the analytes targeted, signaling types used, and pattern recognition.Developing specific receptors for the solution-based analysis of complex analytes and mixtures is a daunting task. A solution to this difficult task has been inspired by nature's use of arrays of receptors in the senses of taste and smell. An emerging field within supramolecular chemistry is the use of synthetic and readily available receptors in array formats for the detection of analytes in solution. Each receptor in a differential array does not necessarily have selectivity for a particular analyte, but the combined fingerprint response can be extracted as a diagnostic pattern visually, or using chemometric tools. This new genre of molecular recognition is advancing rapidly with several groups developing novel array platforms and receptors.     

Noncovalent Chirality Sensing Ensembles for the Detection and Reaction Monitoring of Amino Acids,Peptides, Proteins,and Aromatic Drugs

Ternary complexes between the macrocyclic host cucurbit[8]uril, dicationic dyes, and chiral aromatic analytes afford strong induced circular dichroism (ICD) signals in the near‐UV and visible regions. This allows for chirality sensing and peptide‐sequence recognition in water at low micromolar analyte concentrations. The reversible and noncovalent mode of binding ensures an immediate response to concentration changes, which allows the real‐time monitoring of chemical reactions. The introduced supramolecular method is likely to find applications in bioanalytical chemistry, especially enzyme assays, for drug‐related analytical applications, and for continuous monitoring of enantioselective reactions, particularly asymmetric catalysis.     

典型锕系超分子组装体的构筑原理及研究进展

锕系超分子化学是锕系元素化学的重要研究领域,可以为乏燃料后处理的配位化学基础研究提供重要信息,并为探索锕系功能材料在发光、传感、催化和分离等方面的功能应用提供关键材料体系。本文介绍了基于锕系金属离子的金属-有机超分子组装体这一新兴领域的最新研究进展。从锕系超分子组装体的构筑原理出发并结合笔者自身研究情况,对基于主客体准轮烷配体的锕系-轮烷配位聚合物、具有闭合结构的锕系配位组装体和基于超分子相互作用的锕系超分子聚合物这三类典型的锕系超分子组装体的研究进展进行了梳理和总结阐述。期望为未来新型锕系超分子组装体的设计合成提供参考,促进相关领域的进步和发展。     

Anion recognition using dimetallic coordination complexes

This article describes advances made over the past 3 years in anion recognition using coordination complexes, with a specific focus on dimetallic architectures that utilize a bridging mechanism. The formation of coordination complexes is a relatively straightforward method of constructing fluorescent and colorimetric chemosensors and imaging agents, and a particularly effective way to develop indicator displacement assays that operate in water. These assays are likely to find increased application in various aspects of analytical and environmental chemistry, as well as biomedical imaging and drug discovery. Significant progress in phosphoesterase mimics has been made, and concomitant with the increased mechanistic insight, is the discovery of a catalyst that cleaves phosphodiesters with poor O-alkyl leaving groups. Also discussed is a macrocyclic coordination complex whose shape and supramolecular function is pH-dependent.     

Design of Dual‐Emission Chemosensors for Ratiometric Detection of ATP Derivatives

Nucleoside pyrophosphate (nucleoside PP) derivatives are widespread in living cells and play pivotal roles in various biological events. We report novel fluorescence chemosensors for nucleoside PPs that make use of coordination chemistry. The chemosensors, which contain two Zn^II–dipicolylamine units, bind strongly to nucleoside PPs (K_app>10⁶ M ^?1) in aqueous solution and sense them by a dual‐emission change. Detailed fluorescence and UV/Vis spectral studies revealed that the emission changes of the chemosensors upon binding to nucleoside PPs can be ascribed to the loss of coordination between Zn^II and the acridine fluorophore. This is a unique sensing system based on the anion‐induced rearrangement of the coordination. Furthermore, we demonstrated the utility of these chemosensors in real‐time monitoring of two important biological processes involving nucleoside PP conversion: the apyrase‐catalyzed hydrolysis of nucleoside PPs and the glycosyl transfer catalyzed by β‐1,4‐galactosyltransferase.     

Calixarene‐Based Chemosensors by Means of Click Chemistry

Click chemistry, a new strategy for organic chemistry, has been widely used in the chemical modification of calixarenes because of its reliability, specificity, biocompatibility, and efficiency. Click‐derived triazoles also play a critical role in sensing ions and molecules. This in‐depth review provides an overview of calixarene‐based chemosensors that incorporate click‐derived triazoles, and their three characteristics (chromogenic, fluorescence, and wettability) are reviewed.