共查询到20条相似文献,搜索用时 15 毫秒
1.
Qing Zhang Bo Wu Dan Zhong Xiaowei Zhan Guojie Wang 《Macromolecular rapid communications》2016,37(24):2052-2056
A simple and low‐cost method is reported here for synthesizing polymer dots (PDs) using branched polyethyleneimine and peryleneimide derivatives as precursors heated in dimethylacetamide. The as‐prepared PDs can be well‐dispersed in water and show excitation‐dependent fluorescence, stable fluorescence over a wide range (pH = 5.0 – 9.0), and high photostability. It is demonstrated that the prepared PDs can be used as a novel fluorescent sensing platform for sensitive and selective detection of Fe (III) ions. The fluorescent PDs may be applied to promising applications in chemical sensors for metal ions, as well as biological imaging or biological labeling for their excellent fluorescence properties.
2.
Konggang Qu Jiasi Wang Prof. Dr. Jinsong Ren Prof. Dr. Xiaogang Qu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(22):7243-7249
A facile, economic and green one‐step hydrothermal synthesis route using dopamine as source towards photoluminescent carbon nanoparticles (CNPs) is proposed. The as‐prepared CNPs have an average size about 3.8 nm. The emission spectra of the CNPs are broad, ranging from approximately 380 (purple) to approximately 525 nm (green), depending on the excitation wavelengths. Due to the favorable optical properties, the CNPs can readily enter into A549 cells and has been used for multicolor biolabeling and bioimaging. Most importantly, the as‐prepared CNPs contain distinctive catechol groups on their surfaces. Due to the special response of catechol groups to Fe3+ ions, we further demonstrate that such wholly new CNPs can serve as a very effective fluorescent sensing platform for label‐free sensitive and selective detection of Fe3+ ions and dopamine with a detection limit as low as 0.32 μM and 68 nM , respectively. The new “mix‐and‐detect” strategy is simple, green, and exhibits high sensitivity and selectivity. The present method was also applied to the determination of Fe3+ ions in real water samples and dopamine in human urine and serum samples successfully. 相似文献
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Dr. Shuangyan Wu Dr. Mingchang Zhu Dr. Ying Zhang Prof. Marina Kosinova Prof. Vladimir P. Fedin Prof. Enjun Gao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(14):3137-3144
As a hot topic of global concern, the distinguishing and detecting of antibiotic pollution is crucial owing to its adverse effect on ecosystems and human health stemming from excessive use and poor management. Herein, a water-stable lanthanide coordination polymer sensor (Dy-TCPB) with multiple emitting centers is prepared. The versatile Dy-TCPB can conveniently differentiate various antibiotics, and displays a self-calibration luminescent response to nitrofurazone (NFZ) and furazolidone (FZD). Each antibiotic exhibits notable correlation to a unique combination of the two ligand-to-Dy ion emission intensity ratios, enabling two-dimensional fingerprint recognition. Furthermore, the novel self-calibration sensor demonstrates effective recognition of NFZ and FZD with excellent sensitivity and selectivity, and detection limits as low as 0.0476 and 0.0482 μm for NFZ and FZD, respectively. The synthetic approach for the fabrication of a singular coordination polymer exhibiting multiple emissions provides a promising strategy for the development of facile and effective ratiometric sensors. 相似文献
5.
Elena G. Shcherbakova Dr. Valentina Brega Dr. Tsuyoshi Minami Sara Sheykhi Prof. Dr. Tony D. James Prof. Dr. Pavel Anzenbacher Jr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(29):10074-10080
A highly accurate and reliable screening method for enantiomeric excess of amine derivatives in the presence of water is reported. The fluorescence‐based screening system has been realized by self‐assembly of chiral diol‐type dyes (BINOL, VANOL and VAPOL), 2‐formylphenylboronic acid, and chiral amines forming iminoboronate esters. The structure and chirality of the amine analytes determine the stability of the diastereomeric iminoboronate esters, which in turn display differential fluorescence. The fluorescence signal reflects the enantiomeric purity of the chiral amines and was utilized in high‐throughput arrays. The arrays were able to recognize enantiomeric excess of amines, amino esters, and amino alcohols. In addition to qualitative analysis, quantitative experiments were successfully performed. Studies of the role of additives such as water or citrate were carried out to gain insight into the stability of the iminoboronate esters. It is shown that the above additives destabilize less stable esters while the stable esters remain unchanged. Thus, the presence of water and citrate leads to increased difference between the diastereomeric iminoboronates and contributes to the enantiodiscrimination of the chiral amines. 相似文献
6.
Highly Luminescent N‐Doped Carbon Quantum Dots as an Effective Multifunctional Fluorescence Sensing Platform 下载免费PDF全文
Dr. Zhaosheng Qian Juanjuan Ma Xiaoyue Shan Dr. Hui Feng Prof. Linxiang Shao Prof. Jianrong Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(8):2254-2263
The doping of carbon quantum dots with nitrogen provides a promising direction to improve fluorescence performance and broaden their applications in sensing systems. Herein we report a one‐pot solvothermal synthesis of N‐doped carbon quantum dots (NCQDs) and the synthesis of a series of NCQDs with different nitrogen contents. The as‐prepared NCQDs were compared with carbon quantum dots (CQDs); the introduction of nitrogen atoms largely increased the quantum yield of NCQDs and highest emission efficiency is up to 36.3 %. The fluorescence enhancement may originate from more polyaromatic structures induced by incorporated nitrogen atoms and protonation of nitrogen atoms on dots. It was found that NCQDs can act as a multifunctional fluorescence sensing platform because they can be used to detect pH values, AgI, and FeIII in aqueous solution. The fluorescence intensity of NCQDs is inversely proportional to pH values across a broad range from 5.0 to 13.5, which indicates that NCQDs can be devised as an effective pH indicator. Selective detection of AgI and FeIII was achieved based on their distinctive fluorescence influence because AgI can significantly enhance the fluorescence whereas FeIII can greatly quench the fluorescence. The quantitative determination of AgI can be accomplished with NCQDs by using the linear relationship between fluorescence intensity of NCQDs and concentration of AgI. The sensitive detection of H2O2 was developed by taking advantage of the distinct quenching ability of FeIII and FeII toward the fluorescence of NCQDs. Cellular toxicity test showed NCQDs still retain low toxicity to cells despite the introduction of a great deal of nitrogen atoms. Moreover, bioimaging experiments demonstrated that NCQDs have stronger resistance to photobleaching than CQDs and more excellent fluorescence labeling performance. 相似文献
7.
Daigeun Kim Geunseok Jang Jongho Kim Seongwon Seo Won Ho Park Taek Seung Lee 《Macromolecular rapid communications》2012,33(18):1510-1516
A highly efficient colorimetric and fluorescence turn‐off probe for the sensitive and selective detection of the biologically important amino acid, cysteine (Cys), is demonstrated using a newly synthesized water‐soluble hyperbranched polymer (HP) containing sulfonic acid groups. The detection mechanism involves two steps: (i) the slight quenching of HP in the presence of Co2+ in advance; and (ii) the gradual quenching of the HP–Co2+ complex according to the concentration of Cys due to the absorption screening effect of the formation of the Cys‐Co2+ complex, which prevents HP from absorbing excitation energy. 相似文献
8.
Ron Orbach Lena Mostinski Dr. Fuan Wang Prof. Itamar Willner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(46):14689-14694
Polymerase/nicking enzymes and nucleic‐acid scaffolds are implemented as DNA machines for the development of amplified DNA‐detection schemes, and for the design of logic gates. The analyte nucleic acid target acts, also, as input for the logic gates. In the presence of two DNA targets, acting as inputs, and appropriate DNA scaffolds, the polymerase‐induced replication of the scaffolds, followed by the nicking of the replication products, are activated, leading to the autonomous synthesis of the Mg2+‐dependent DNAzyme or the Mg2+‐dependent DNAzyme subunits. These biocatalysts cleave a fluorophore/quencher‐functionalized nucleic‐acid substrate, thus providing fluorescence signals for the sensing events or outputs for the logic gates. The systems are used to develop OR, AND, and Controlled‐AND gates, and the DNA‐analyte targets represent two nucleic acid sequences of the smallpox viral genome. 相似文献
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Luminescent coordination polymers can be potential chemosensors and extensive efforts are being devoted to improve their selectivity and sensitivity. In this work, we report a new kind of fluorene‐based Tb‐CP, Tb4L6·7DMF·5H2O ( Tb 4 L 6 , H2L = 4,4′‐(9,9‐dimethyl‐9H‐fluorene‐2,7‐diyl)dibenzoic acid), showing 2D network and strong blue emission. Meanwhile, Tb 4 L 6 exhibits excellent selectivity and sensitivity for picric acid (PA). The quenching constant (Ksv) of Tb 4 L 6 is equal to 4.5 × 104 L/mol during the concentration range of 0–30 μmol/L, which approaches the best reported CPs‐based on PA sensor up to now. Moreover, we went into depth on the possible mechanisms of luminescence quenching. 相似文献
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Qingling Xu Chunxian Wu Chunlei Zhu Xinrui Duan Prof. Libing Liu Dr. Yuchun Han Prof. Yilin Wang Prof. Shu Wang 《化学:亚洲杂志》2010,5(12):2524-2529
Rapid and sensitive methods to detect proteins and protein denaturation have become increasingly needful in the field of proteomics, medical diagnostics, and biology. In this paper, we have reported the synthesis of a new cationic water‐soluble conjugated polymer that contains fluorene and diene moieties in the backbone ( PFDE ) for protein identification by sensing an array of PFDE solutions in different ionic strengths using the linear discriminant analysis technique (LDA). The PFDE can form complexes with proteins by electrostatic and/or hydrophobic interactions and exhibits different fluorescence response. Three main factors contribute to the fluorescence response of PFDE , namely, the net charge density on the protein surface, the hydrophobic nature of the protein, and the metalloprotein characteristics. The denaturation of proteins can also be detected using PFDE as a fluorescent probe. The interactions between PFDE and proteins were also studied by dynamic light scattering (DLS) and isothermal titration microcalorimetry (ITC) techniques. In contrast to other methods based on conjugated polymers, the synthesis of a series of quencher or dye‐labeled acceptors or protein substrates has been avoided in our method, which significantly reduces the cost and the synthetic complexity. Our method provides promising applications on protein identification and denaturation detection in a simple, fast, and label‐free manner based on non‐specific interaction‐induced perturbation of PFDE fluorescence response. 相似文献
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Marianna Rossetti Simone Brannetti Marco Mocenigo Bruna Marini Rudy Ippodrino Alessandro Porchetta 《Angewandte Chemie (International ed. in English)》2020,59(35):14973-14978
Easy‐to‐use platforms for rapid antibody detection are likely to improve molecular diagnostics and immunotherapy monitoring. However, current technologies require multi‐step, time‐consuming procedures that limit their applicability in these fields. Herein, we demonstrate effective molarity‐driven electrochemical DNA‐based detection of target antibodies. We show a highly selective, signal‐on DNA‐based sensor that takes advantage of antibody‐binding‐induced increase of local concentration to detect clinically relevant antibodies in blood serum. The sensing platform is modular, rapid, and versatile and allows the detection of both IgG and IgE antibodies. We also demonstrate the possible use of this strategy for the monitoring of therapeutic monoclonal antibodies in body fluids. Our approach highlights the potential of harnessing effective molarity for the design of electrochemical sensing strategies. 相似文献
12.
Mianqi Xue Xinlei Ma Zhuang Xie Liting Duan Yuqian Jiang Dr. Meining Zhang Prof. Tingbing Cao 《化学:亚洲杂志》2010,5(10):2266-2270
Gold‐directed polypyrrole (PPy) nanoarrays are fabricated by hydrogel‐assisted nanotransfer edge printing (HnTEP) and electrochemical polymerization. Gold nanoarrays are fabricated through the HnTEP method, which involves metal deposition, hydrogel etching, and nanotransfer edge printing. By utilizing the well‐positioned gold nanostructures, PPy nanoarrays with smooth morphology and controllable dimensions are fabricated through in situ electrochemical polymerization, the results of which are characterized by scanning electron microscopy and atomic force microscopy. A gas sensor based on PPy nanoarrays results in excellent sensing capabilities towards NH3 detection, especially the sensitivity and fast response. This method appears to be general and may aid in the future design and implementation of other active materials which can also be manipulated by the same procedure and serve as functional components for chemical sensing, optoelectronics, biodetection, and other applications. 相似文献
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Young Hoon Lee Dr. Hongguang Liu Jin Yong Lee Prof. Sang Hoon Kim Sung Kuk Kim Jonathan L. Sessler Prof. Yang Kim Prof. Jong Seung Kim Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(20):5895-5901
A new chemosensor‐based approach to the detection of nitroaromatics is described. It involves the analyte‐induced quenching of excimer emission of a dipyrenyl calix[4]arene ( L ). The chemical and photophysical properties of the complexes formed between L and mono‐, di‐, and trinitrobenzene, and di‐ and trinitrotoluene were studied in acetonitrile and chloroform by using 1H NMR, UV/Vis, and fluorescence spectroscopy. Fluorescence spectroscopy revealed that the trinitroaromatics engendered the largest response among the various substrates tested, with the sensitivity for these analytes being correspondingly high. Quantitative analysis of the fluorescence titration profile generated from the titration of L with TNT provided evidence that this particular functionalized calix[4]arene receptor allows for the detection of TNT down to the low ppb level in CH3CN. A single‐crystal X‐ray diffraction analysis revealed that in the solid state the complex L? TNT consists of a supramolecular crystalline polymeric structure, the formation of which appears to be driven by intermolecular π–π interactions between two pyrene units and a TNT molecule held at a distance of 3.2–3.6 Å, as well as by intra‐ and intermolecular hydrogen‐bonds among the amide linkages. Nevertheless, the changes in the 1H NMR, UV/Vis, and fluorescence spectrum, including sharp color changes, are ascribed to a charge‐transfer interaction arising from complementary π–π overlap between the pyrene subunits and the bound trinitroaromatic substrates. A number of ab initio calculations were also carried out and, considered in concert, they provide further support for the proposed charge‐transfer interactions, particularly in the case of L? TNT. 相似文献
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Complex‐Formation‐Enhanced Fluorescence Quenching Effect for Efficient Detection of Picric Acid 下载免费PDF全文
Dr. Aixiang Ding Longmei Yang Yuyang Zhang Dr. Gaobin Zhang Prof. Lin Kong Dr. Xuanjun Zhang Prof. Yupeng Tian Prof. Xutang Tao Prof. Jiaxiang Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(38):12215-12222
Amine‐functionalized α‐cyanostilbene derivatives (Z)‐2‐(4‐aminophenyl)‐3‐(4‐butoxyphenyl)acrylonitrile (ABA) and (Z)‐3‐(4‐butoxyphenyl)‐2‐[4‐(butylamino)phenyl]acrylonitrile (BBA) were designed for specific recognition of picric acid (PA), an environmental and biological pollutant. The 1:1 host–guest complexes formed between the chemosensors and PA enhanced fluorescence quenching, thus leading to sensitive and selective detection in aqueous media and the solid phase. 相似文献
16.
Yasumasa Kanekiyo Hiroaki Sato Hiroaki Tao 《Macromolecular rapid communications》2005,26(19):1542-1546
Summary: A novel fluorometric saccharide detection strategy has been established by utilizing saccharide‐induced conformational changes in copolymers containing boronic acid and fluorescent units. The polymer chain changes its conformation due to an alteration of the charge state induced by binding with saccharides. The conformational changes are conveniently detected by monitoring excimer to monomer intensity ratio in the fluorescence spectra. Thus, the present strategy would be a promising way for the creation of highly selective and sensitive saccharide‐sensing systems.
17.
Liping Heng Dr. Xinyi Wang Yongqiang Dong Dr. Jin Zhai Prof. Ben Zhong Tang Prof. Tianxin Wei Prof. Lei Jiang Prof. 《化学:亚洲杂志》2008,3(6):1041-1045
A fluorescent organic small molecule, hexaphenylsilole (HPS), has been used as a sensing material, while a HPS/polymethyl methacrylate composite film with a lotus leaf like structure is prepared by a simple electrospin method. The film shows high stability and excellent sensitivity for the metal ions Fe3+ and Hg2+, respectively. The special surface morphology containing micro‐/nanocomposite structure is attributed to the exhibition of these unusual properties. 相似文献
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Qingsong Liu Changli Zhang Xiaoqing Wang Shuwen Gong Weijiang He Zhipeng Liu 《化学:亚洲杂志》2016,11(2):202-206
Due to the similar structure and reactivity of cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), the simultaneous discrimination of Cys over Hcy and GSH by a single fluorescent sensor is still a great challenge. In this work, a benzothiazole‐pyimidine‐based boron difluoride complex ( BPB ) was developed as a new fluorescent sensor for Cys. The sensor exhibits a highly selective “turn‐on” response to cysteine over Hcy, GSH and other amino acids in aqueous solution at physiological pH. The observed pseudo‐first‐order rate constant for the reaction of BPB with Cys was calculated to be about 0.062 min−1. The detection limit of this sensor for Cys was determined to be 332 nm, and bioimaging of exogenous Cys by this sensor was successfully applied in living cells, thus indicating that this sensor holds great potential for biological applications. 相似文献
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Lourdes Basabe‐Desmonts Dr. Chien‐Ching Wu Kees O. van der Werf Maria Peter Dr. Martin Bennink Dr. Cees Otto Dr. Aldrik H. Velders Dr. David N. Reinhoudt Prof Dr. Vinod Subramaniam Prof. Dr. Mercedes Crego‐Calama Dr. 《Chemphyschem》2008,9(12):1680-1687
Fluorescent self‐assembled monolayers (SAMs) are used as dip‐pen nanolithography (DPN) substrates for the fabrication of patterns of Ca2+ and Cu2+ ions. The driving force for the transfer of these ions from an atomic force microscopy (AFM) tip to the surface is their complexation to organic ligands on the monolayer. By means of fluorescent surfaces, the patterns can be visualized under a fluorescence microscope. We use a custom‐built atomic force fluorescence microscope (AFFM), a combination of atomic force and confocal fluorescence microscopes, to deposit the metal ions onto the sensing SAMs by DPN and to subsequently visualize modulations of fluorescence intensity in a sequential write–read mode. 相似文献
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Shudipto Konika Dishari Kan‐Yi Pu Bin Liu 《Macromolecular rapid communications》2009,30(19):1645-1650
We report a macromolecular end‐capping approach to improve the detection sensitivity of cationic conjugated polymer (CCP) based DNA detection. A phenylethynyl anthracene (PEA) end‐capped cationic polyfluorene (PF) derivative ( P1 ) is synthesized via Suzuki coupling. Due to efficient fluorescence resonance energy transfer (FRET) from the polymer backbone to the end‐capper PEA units, the polymer ( P1 ) fluorescence is dominated by the emission from PEA even in dilute aqueous solution. P1 emission has a better spectral overlap with fluorescein (Fl) absorption compared to that for uncapped PF ( P2 ). In addition, the intra and intermolecular energy transfer for P1 is more efficient in the presence of DNA due to complexation‐induced polymer aggregation. These impart a combinatorial FRET between P1 and an Fl‐labeled probe which is more efficient than that between P2 and the same probe. P1 thus offers a better DNA detection sensitivity relative to P2 and opens up new opportunities to improve the performance of CCP based biosensors involving FRET.