Frontiers in Chemistry
·
2020
·
IF 3.693
Ai Qiushuang,Fu Qiang,Liang Feng
Recognition tunneling technique owns the capability for investigating and characterizing molecules at single molecule level. Here, we investigated the conductance value of cucurbit[7]uril (CB[7]) and melphalan@CB[7] (Mel@CB[7]) complex molecular junctions by using recognition tunneling technique. The conductances of CB[7] and Mel@CB[7] with different pH values were studied in aqueous media as well as organic solvent. Both pH value and guest molecule have an impact on the conductance of CB[7] molecular junction. The conductances of CB[7] and Mel@CB[7] both showed slightly difference on the conductance under different measurement systems. This work extends the molecular conductance measurement to aqueous media and provides new insights of pH-responsive host-guest system for single molecule detection through electrical measurements.
研究领域:
生物物理学
·
纳米科学
·
分子电子学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2021
·
IF 0.782
Jue Chen,Tengmei Gao,Yinxia Chang,Yanming Wei,Yonghui Wang
Folate (FA) plays a key role in the biosynthesis of amino acids, purines, and pyrimidines in the human body, and intracellular folate metabolism has become an attractive target of tumor chemotherapy. In this work, an inclusion interaction was found between FA and cucurbit[7]uril (CB[7]), and the formation of a CB[7]-FA 2:1 supramolecular inclusion complex was confirmed by fluorescence spectra, UV-Vis absorption spectroscopy, 1H NMR, and molecular modeling calculations. In addition, FA is generally determined through the indirect fluorescent method because it shows weak fluorescence in aqueous solution. Therefore, a simple, direct fluorescence probe method for rapidly measuring FA was investigated, and the linear equation of FA was ΔF = 14.691C + 37.366 within the concentration ranges of 0.82 ~ 18.31 µg mL–1. The proposed direct fluorescence method was applied to the determination of spiked plasma. We demonstrated that this method could provide an experimental basis for the targeted administration of the CB[7]-FA complex, and it could be extended as a promising fluorescence detection method for drugs in vivo.
研究领域:
生物化学
·
分析化学
·
药物化学
✓ 已验证
产品关联
DOI
高影响因子
ChemPlusChem
·
2020
·Vol. 85
·期 4
·679-683
·
IF 2.753
Shengke Li,Kit Ieng Kuok,Xia Ji,Anni Xu,Hang Yin,Jun Zheng,Huaping Tan,Ruibing Wang
Graphical Antibacterial switch : The capability of cucurbit[7]uril (CB[7]) in modulating the antibacterial activity of ambroxol hydrochloride (ABX) was successfully demonstrated by using two strains of Pseudomonas aeruginosa and Escherichia coli . The antibacterial activity of ABX was “turned off” upon encapsulation by CB[7] and “turned on” after ABX was released from the CB[7]-ABX host–guest complex upon addition of a competitive guest amantadine hydrochloride. Supramolecular encapsulation by cucurbit[7]uril (CB[7]) was recently demonstrated to provide a simple and efficient method for antibacterial activity regulation of antibiotics. In this work, CB[7] was shown to form binary host-guest complex with ambroxol hydrochloride (ABX), a clinical mucokinetic and expectorant drug, which was reported to exhibit certain antibacterial activity. 1 H NMR titration and isothermal titration calorimetry experiment results suggested that the 4-hydroxyl cyclohexylamine group of ABX was included inside the CB[7] cavity, with a binding constant K a of (6.69±0.11)×10 5 M −1 in phosphate buffered saline (PBS) solution, thermodynamically driven by both enthalpy change (ΔH=−12.2 kJ/mol) and entropy change (TΔS=21.1 kJ/mol). More importantly, ABX's inhibitory activity (MIC 50 ) against bacillary strains towards Pseudomonas aeruginosa and Escherichia coli strains was decreased from (5.11±0.31)×10 −6 M −1 and (2.63±0.34)×10 −5 M −1 to zero upon encapsulation by CB[7], and was subsequently recovered to almost its original activity when a competitive guest, amantadine hydrochloride, for disassembling CB[7]-ABX complex, was added, suggesting that the antibacterial activity of ABX could be readily “turned off/on” upon its complexation and decomplexation with CB[7].
研究领域:
药理学
·
微生物学
·
化学
✓ 已验证
DOI
高影响因子
Advanced Healthcare Materials
·
2018
·Vol. 8
·期 2
·1801458
·
IF 5.609
Haishi Qiao,Jing Jia,Wei Chen,Bin Di,Oren A. Scherman,Chi Hu
The fabrication, characterization, and therapy efficiency of a noncovalent-bonded hydrogel network, which is assembled by utilizing cucurbit[7]uril as a supramolecular linker to “stick” superparamagnetic γ-Fe 2 O 3 nanoparticles onto the polymer backbone of catechol-functionalized chitosan are described. The unique barrel-shaped structure of cucurbit[7]uril not only facilitates host–guest recognition with the catechol derivatives, but also forms robust electrostatic interactions between its carbonyl portals and the γ-Fe 2 O 3 nanoparticles in a supramolecular manner, which leaves the physical and chemical properties of the nanoparticles intact. The γ-Fe 2 O 3 nanoparticles display vibrational movement and heat generation under an alternating magnetic field, endowing the formed hybrid supramolecular hydrogel with both thermo- and chemotherapy modalities, which are demonstrated both in vitro and in vivo. Here, a facile strategy is introduced to construct noncovalent interactions between a polymer matrix and the incorporated nanoparticles, which is amendable to a wide range of biomedical and industrial applications.
研究领域:
生物材料
·
纳米医学
·
肿瘤治疗
✓ 已验证
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2021
·
IF 4.098
Qin Wang,Li-Bing Lü,Zhu Tao,Tao Sun,Qing Tang,Ying Huang
In the present work, we have investigated the effect of pH and mercury ions on the host–guest complex formed between cucurbit[7]uril (Q[7]) and Hoechst 33342 (H33342). 1 H NMR, UV–vis and fluorescence spectroscopy revealed that acid/base stimulation could change the binding stoichiometry between Q[7] and H33342. The results suggest that two complexation equilibria (1:1 and 2:1) may exist between H33342 and Q[7] at pH 2.0 and 4.5, respectively. However, a 1:1 host–guest complex was formed between H33342 and Q[7] at pH 7.0 and 10.0. Q[7] shows differential affinities for the protonated and neutral forms of H33342 dye. Moreover, the switching between H33342∙2H + @2Q[7](1:2) at pH 4.5 and H33342∙H + @Q[7](1:1) at pH 7.0 was reversible. Furthermore, as a metal stimulus, Hg 2+ ions could push (i) Q[7] from the piperazine ring to the benzimidazole position with a 1:1 guest–host ratio and (ii) a second Q[7] onto the ethyl position with a 1:2 guest–host stoichiometry. This stimulus response system will have potential applications in the field of molecular switch design.
研究领域:
超分子化学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Dong-Xue Xia,Xin Wang,Wen-Qi Sun,Rui-Lian Lin,Jing-Xin Liu,Ying-Wei Yang
Inspired by Chameleons' skin color tuning in response to environmental changes, we design and prepare three inclusion complexes based on the cucurbit[7]uril (Q[7]) host and three viologen guests. Upon light irradiation, the colors of these inclusion complexes in the solid state turn from light colors to vivid three primary colors, i.e., red, green, and blue, respectively. Ultraviolet–visible (UV–vis) diffuse reflectance and electron spin resonance (ESR) spectra reveal that the photochromism can be attributed to the generation of viologen radicals, originating from the photoinduced electron transfer. The results of quantum chemical calculation indicate that Q[7] in the inclusion complexes acts as the electron donor in the photoinduced electron transfer process. Using a color mixing approach and finely manipulating the proportions of the three inclusion complexes, a series of composite photochromic materials (CPMs) can be manufactured, covering a full-color gamut in visible light. On the other hand, due to the ignorable size and shape change of CPMs during the photochromatic processes, the CPMs-based reversible photochromic “printing” and photofading “erase” properties were also used for quick response (QR) code. Therefore, these prominent intelligent features of CPMs open new avenues to explore optical regulated nano-platforms for multiple anti-counterfeiting, biomimetics, and military camouflage applications.
研究领域:
材料科学
·
化学
·
仿生学
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2024
·Vol. 12
·期 23
·2400839
·
IF 8
Xiao-Feng Wang,Rui-Lian Lin,Wen-Qi Sun,Jing-Xin Liu,Li-Xin Xu,Carl Redshaw,Xing Feng
Multistimuli-responsive color-changing materials have potential applications in areas such as chemical sensing and anti-counterfeiting. In this work, a fluoro-phenyl-acetyl-substituted viologen derivative (FPAV·Cl 2 ) is synthesized, which can form a supramolecular inclusion complex with cucurbit[7]uril (Q[7]) via self-assembly. Significantly, the resulting inclusion complex FPAV 2+ @Q[7] in the solid-state exhibits visual color changes in response to multiple external stimuli including light, heat, and vapors of ammonia and organic amines. The electron spin resonance (ESR) and ultraviolet–visible (UV–vis) spectra analysis reveals that the photochromic, thermochromic, and vapochromic behavior of FPAV 2+ @Q[7] is due to the generation of FPAV +• free radicals resulting from electron transfer. Furthermore, in the solid-state, FPAV 2+ @Q[7] shows controllable fluorescence regulated by its chromic process. Based on the multi stimuli-responsive color-changes and fluorescence properties of FPAV 2+ @Q[7], its practical applications in erasable inkless printing, multiple anti-counterfeiting processes, visible ammonia/organic amines detection, and information encryption are demonstrated. The supramolecular strategy of encapsulating viologen derivatives into macrocycles provides a general method for fabricating multi stimuli-responsive chromic materials with multiple practical applications.
研究领域:
超分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2019
·
IF 1.795
Mei-Xiang Yang,Ming Liu,Mei Yang,Qin Wang,Xi Zeng,Zhu Tao,Xin Xiao,Ying Huang
In the present work, a well-known host–guest inclusion complex comprising a cucurbit[7]uril (Q[7]) and an important biological dye, Hoechst-33258 (H33258) was selected as a fluorescence probe. In contrast to the pH conditions in which H33258 is exhibited in the literature, these being, mono- or di-protonated states, in the present work, we selected an extreme case, whereby H33258 was displayed in an anionic state (pH = 11). The investigation of the host–guest interaction demonstrated similar inclusion modes in a wide pH range, that is the dumbbell-like inclusion complex in which one Q[7] includes piperazine moiety and another Q[7] includes the phenol moiety of H33258. Moreover, investigation on the binding capacity of the 15 selected anions under three representative pH levels (pH = 2, pH = 4.5 and pH = 11, respectively) indicated that the H33258@Q[7] probe displayed unique selectivity on HPO 4 2 − anion in medium at pH = 11. More importantly, the probe could open a new platform in Q[ n ]-chemistry, that is the Q[ n ]-based host–guest interaction systems can apply in anion recognition or response.
研究领域:
化学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Qiuxiang Mao,Lancheng Wang,Dandan Xue,Xiaoxuan Lin,Fang Sun,Pengcheng Xu,Jieru Chen,Wenying Li,Xiuchen Li,Fang Yan,Chi Hu
Although multiple forms of dimers have been described for GPCR, their dynamics and function are still controversially discussed field. Fluorescence microscopy allows GPCR to be imaged within their native context; however, a key challenge is to site-specifically incorporate reporter moieties that can produce high-quality signals upon formation of GPCR dimers. To this end, we propose a supramolecular sensor approach to detect agonist-induced dimer formation of μ-opioid receptors (μORs) at the surface of intact cells. With the macrocyclic host cucurbit[7]uril and its guest hemicyanine dye tethered to aptamer strands directed against the histidine residues, the sensing module is assembled by host–guest complexation once the histidine-tagged μORs dimerize and bring the discrete supramolecular units into close proximity. With the enhanced sensitivity attributed by the “turn-on” fluorescence emission and high specificity afforded by the intermolecular recognition, in situ visualization of dynamic GPCR dimerization was realized with high precision, thereby validating the supramolecular sensing entity as a sophisticated and versatile strategy to investigate GPCR dimers, which represent an obvious therapeutic target.
研究领域:
药理学
·
细胞生物学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2020
·
IF 4.613
Guangliang Hou,Shenxi Min,Yuhan Zhao,Bin Dong,Lina Zhang,Dahua Li,Weichun Wu,Huifang Zhu,Bo Song
In this study, we synthesized an amphiphilic α-cyanostilbene derivative ( E -form)-1-(12-(2-(2-(benzo[d]thiazol-2-yl)-2-cyanovinyl)-5-(diethylamino)phenoxy)dodecyl)pyridin-1-ium bromide (denoted by BCPB). As being dissolved in aqueous solution, BCPB shows strong emission of excimers at around 660 nm due to the formation of aggregates. Addition of different amount of CB[7] into the solution leads to the emission shift from 660 nm, firstly to 540 nm and then to 588 nm. The emission shift is attributed to the two-step assembly driven by the concentration of CB[7], and the molar ratios of CB[7]/BCPB (denoted by R m ) play a critical role for the shift. As R m ≤ 4, CB[7] mainly interacts with the cationic pyridinium group of BCPB to form BCPB@CB[7] complex. As R m > 4, another CB[7] binds to the diethylamino group at one end of α-cyanostilbene to form BCPB@CB[7] 2 complex. The two-step assembly well explains the emission shift of BCPB.
研究领域:
超分子化学
·
材料科学
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2022
·Vol. 53
·期 5
·1023-1032
·
IF 2.925
Luo Yuhua,Yao Haifeng,Zhang Yahui,Dong Yongping
Abstract In this paper, a sensitive electrochemiluminescence (ECL) method for the detection of Ba 2+ was proposed based on its apparent enhancing effect on the anodic luminol ECL at a cucurbit[7]uril (Q[7])-modified glassy carbon electrode (Q[7]/GCE). The cavity of the modified Q[7] could accommodate more dissolved oxygen at the electrode surface which reacted with luminol to generate strong anodic ECL signal compared with a bare GCE. Ba 2+ ions exhibited further enhancing effect on luminol ECL when they were immobilized at the portal of Q[7] through chelating with carbonyl group of Q[7]. The increment of ECL signal varied linearly with the concentration of Ba 2+ , as a result, an ECL sensor for the quantitative detection of Ba 2+ was constructed. Under the optimal condition, Ba 2+ could be sensitively detected in the range of 1.0 × 10 –7 to 1.0 × 10 –4 mol L −1 , and the detection limit was calculated as 10 nM (3σ). The proposed ECL sensor exhibited satisfactory analytical performance and could be used in real samples analysis, which provided a new strategy for metal ions detection. Graphic abstract
The encapsulation of dissolved oxygen by Q[7] can enrich oxygen concentration at
the electrode surface, which can react with luminol to emit enhanced ECL. The
presence of Ba 2+ can increase the amount of O2
•- at the electrode surface through the
formation of barium-peroxide species, which can further enhance luminol ECL. Thus,
an ECL sensor for the sensitive detection of Ba 2+ was built.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2019
·Vol. 13
·期 2
·394-399
·
IF 7.804
Dengmeng Song,Bo Li,Xin Li,Xuzhuo Sun,Jun Li,Chengbo Li,Tongyu Xu,Yong Zhu,Fei Li,Ning Wang
Graphical Get in or get out : A cobaloxime catalyst and Eosin Y photosensitizer were assembled with macrocyclic cucurbit[7]uril through inclusion and exclusion interactions, respectively. The synchronous self-assembly drove an orthogonal arrangement of the ternary system with significant spatial proximity. The ternary supramolecular system showed better performance for photocatalytic H 2 evolution than multicomponent systems. The fabrication of efficient and convenient photocatalytic H 2 evolution systems is a fascinating research topic in the field of solar energy conversion. A ternary self-assembled photocatalytic H 2 evolution system was fabricated through supramolecular host–guest chemistry. The system consisted of the H 2 evolution catalyst [Co(dmgH) 2 (4-ppy) 2 ]NO 3 ( 1 ; dmgH 2 =dimethylglyoxime, 4-ppy=4-phenylpyridine) and the photosensitizer Eosin Y (EY) assembled with the macrocyclic compound cucurbit[7]uril (CB[7]) to form the 1 @CB[7]/EY complex through inclusion and exclusion interactions, respectively. The synchronous self-assembly drives an orthogonal arrangement of the 1 @CB[7]/EY system. The inclusion complex 1 @CB[7] was successfully characterized by 1 H NMR spectroscopy and single-crystal XRD. The exclusion process of CB[7] with EY was identified by NMR titration and the optimized geometry of the exclusion structure was determined by DFT calculations. The use of CB[7] resulted in a 6-fold increase in turnover number, a 3-fold increase in turnover frequency, and a 3-fold extension of lifetime for photocatalytic H 2 evolution as compared with the system in the absence of CB[7]. The improvement of the light-driven H 2 evolution activity was ascribed to the ability of CB[7] to link the photosensitizer and catalyst.
研究领域:
化学
·
材料科学
·
可再生能源研究
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）