共查询到20条相似文献,搜索用时 12 毫秒
1.
A new fluorescent chelator Oxa, having two metal-binding sites, was designed and synthesized in six steps. Oxa exhibited two distinctive dissociation constants for Zn2+ ( μM and μM), with considerable fluorescence increase in aqueous buffer at pH 7.2. Affinities of Oxa for the other biologically important ions such as Ca2+ ( μM and mM) and Mg2+ ( μM and could not be determined) in the same conditions were also obtained. 相似文献
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Jake R. Zimmerman Cody Criss Shelby Evans Mary Ernst Megan Nieszala Alex Stafford Jonathan Szczerba 《Tetrahedron letters》2018,59(25):2473-2476
New scaffolds of sulfonamido-chromone derivatives recently synthesized were found to be effective fluorescent sensors for fluoride anion. This new class of fluorophore showed a blue shift in the emission spectra upon addition of various equivalents of fluoride. These compounds also exhibit excellent selectivity for the fluoride anion via a deprotonation process. They were also shown to have a detection limit of F? down to 0.5?ppm. 相似文献
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超分子化学研究的核心内容之一是主客体分子识别,主体分子通过非共价键作用与客体分子结合并实现一些特定的功能。大环化合物由于拥有特殊的环状结构,可以与客体分子高效结合,配合荧光团可开发性能优异的传感分子,从而受到科研工作者的广泛关注。本文综述了近五年以来冠醚、环糊精、杯芳烃、葫芦脲以及柱芳烃等五类大环化合物作为荧光传感分子的研究进展,并简单介绍了荧光传感器的设计思路、工作原理以及应用,最后对大环荧光传感器的发展作出展望。 相似文献
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Wang Z Palacios MA Zyryanov G Anzenbacher P 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(28):8540-8546
Ratiometric fluorescence-based sensors are widely sought after because they can effectively convert even relatively small changes in optical output into a strong and easy-to-read signal. However, ratiometric sensor molecules are usually difficult to make. We present a proof-of-principle experiment that shows that efficient ratiometric sensing may be achieved by an array of two chromophores, one providing an on-to-off response and the second yielding an off-to-on response in a complementary fashion. In the case that both chromophores emit light of different color, the result is a switching of colors that may be utilized in the same way as from a true ratiometric probe. The chromophore array comprises two sensor elements: i) a polyurethane membrane with embedded N-anthracen-9-yl-methyl-N-7-nitrobenzoxa-[1,2,5]diazo-4-yl-N',N'-dimethylethylenediamine hydrochloride and ii) a membrane with N,N-dimethyl-N'-(9-methylanthracenyl)ethylenediamine. A combination of photoinduced electron transfer (PET) and fluorescence resonance energy transfer (FRET) allows for green-to-blue emission switching in the presence of Zn(II) ions. The sensing experiments carried out with different Zn(II) salts at controlled pH revealed that the degree of color switching in the individual sensor elements depends on both the presence of Zn(II) ions and the counter anion. These results suggest that sensing of both cations and anions may perhaps be extended to different cation-anion pairs. 相似文献
6.
Weiying Lin Lingliang Long Lin Yuan Zengmei Cao Jianbo Feng 《Analytica chimica acta》2009,634(2):262-134
Phenanthroimidazole derivative 1 has been developed as a rare example of ratiometric fluorescent sensors for Fe3+. Interestingly, upon treatment with Fe3+, the sensor displayed a ratiometric fluorescent response with an enhancement of the ratios of emission intensities at 440 and 500 nm from 0.36 to 3.24. The detection range of the sensor for Fe3+ is in the 1.0 × 10−5-1.5 × 10−4 M concentration range and the detection limit is 5.26 × 10−6 M. In addition, the sensor showed good selectivity to Fe3+ with the selectivity coefficients (KFe3+=SFe3+/S0) of Fe3+ over other metal ions tested in the range of 5-68. 相似文献
7.
Ana M. Costero Joaquín Sanchis Salvador Gil Vicente Sanz M. Carmen Ramírez De Arellano J.A. Gareth Williams † 《Supramolecular chemistry》2013,25(6):435-446
Eight new polyazapodands containing a 4,4′-substituted biphenyl moiety have been synthesised. Four (7, 8, 9 and 11) are functionalised on positions 4 and 4′ with a nitro group and four (1, 2, 3 and 10) with a dimethylamino substituent. Comparison of the emission behaviour of 1, 2, 3 with that of the reference compounds 10 and tetramthylbenzidine, clearly suggests that a modification in the dihedral angle between the biphenyl rings is an important factor in determining the fluorescent response of the molecule. The fluorescence is pH dependent, due to the formation of intramolecular hydrogen bonds between protonated aliphatic nitrogens and a carbonyl oxygen, which influences the aforementioned dihedral angle. A crystal structure resolved by X-ray diffraction of 7·2HCl has been determined, and confirms the dependence of the angle and the rigidity on the hydrogen bonding. The complexation properties of these ligands have been studied with Zn2+, Cd2+, Ni2+, Cu2+ and Pb2+, which show that the number of amino groups within the pendants has a strong influence on the nature of the complexation and the fluorescent response of each ligand. 相似文献
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Xiaoqun Gong Huan Yan Jiumin Yang Yudong Wu Jian Zhang Yingyi Yao Ping Liu Huiquan Wang Zhidong Hu Jin Chang 《Analytica chimica acta》2016
Fluorescence-encoded magnetic microbeads (FEMMs), with the fluorescence encoding ability of quantum dots (QDs) and magnetic enrichment and separation functions of Fe3O4 nanoparticles, have been widely used for multiple biomolecular detection as microfluidic protein chip supports. However, the preparation of FEMMs with long-term fluorescent encoding and immunodetection stability is still a challenge. In this work, we designed a novel high-temperature chemical swelling strategy. The QDs and Fe3O4 nanoparticles were effectively packaged into microbeads via the thermal motion of the polymer chains and the hydrophobic interaction between the nanoparticles and microbeads. The FEMMs obtained a highly uniform fluorescent property and long-term encoding and immunodetection stability and could be quickly magnetically separated and enriched. Then, the QD-encoded magnetic microbeads were applied to alpha fetoprotein (AFP) detection via sandwich immunoreaction. The properties of the encoded microspheres were characterized using a self-designed detecting apparatus, and the target molecular concentration in the sample was also quantified. The results suggested that the high-performance FEMMs have great potential in the field of biomolecular detection. 相似文献
9.
Algal fluorescence sensor integrated into a microfluidic chip for water pollutant detection 总被引:1,自引:0,他引:1
We report the first miniaturized fluorescent sensor based on algae, with an organic light emitting diode (OLED) and an organic photodetector (OPD) integrated into a microfluidic chip. The blue emission OLED was used as the excitation source, while a blend of PTB3/PC(61)BM was used for the fabrication of the organic photodetector. Excitation and emission color filters based on acid/base dyes and a metal complex were developed and assembled with the organic optoelectronic components in order to complete the fluorescent detection system. The detection system was then integrated in a microfluidic chip made from (poly)dimethylsiloxane (PDMS). The complete sensor is designed to detect algal fluorescence in the microfluidic chamber. Algal chlorophyll fluorescence enables evaluation of the toxicity of pollutants like herbicides and metals-ions from agricultural run-offs. The entirely organic bioassay here presented allowed detection of the toxic effects of the herbicide Diuron on Chlamydomonas reinhardtii green algae that gave 50% inhibition of the algae photochemistry (EC(50)) with a concentration as low as 11 nM. 相似文献
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The synthesis of the chiral diaza-9-crown-3 derivatives 1 (S,S) and 2 (R,R) is described. These sensors were designed as luminescent chemosensors for lithium where the fluorescence emission from the naphthalene moieties was ‘switched on’ upon Li+ recognition by the crown ether moiety in organic solvents, showing excellent selectivity over other group I and group II cations. Even though the recognition of Li+ was not achieved in water (pH 7.4) or aqueous alcohol solution, the fluorescence (which was switched on at pH 7.4) was substantially modulated by spherical anions, where the fluorescence emission was quenched in the presence of Br− and I− but less by Cl− and not by acetate. This indicates that the emission was quenched by heavy-atom affect. The recognition of Li+ was also investigated by 1H NMR in CD3CN and by observing the changes in the circular dicromism spectra. For the former, the resonances for the crown ether moiety and α-methyl protons adjacent to the ring were sifted upfield and broadened, whereas for 1 the intensity of the CD signal for the π-π transition was substantially modulated upon Li+ recognition. 相似文献
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Salvador Toms Rafel Prohens Ghislain Deslongchamps Pablo Ballester Antoni Costa 《Angewandte Chemie (International ed. in English)》1999,38(15):2208-2211
A set of weak CH⋅⋅⋅O interactions is responsible for the recognition of tetraalkylammonium ions (ball-and-stick structure) by the tripodal receptors depicted in the diagram, in which the binding pocket is lined with squaramide units. The association constants of the fluorescent receptors are remarkably high at about 105 M −1 and can be used for signaling the presence of selected choline phospholipids. Z=RNH, where R=alkyl, arylamino; X−=BH4−, Cl−, Br−, I−. 相似文献
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Md. Taifur Rahman Ilhyong Ryu Koichi Yonemura Kiyoshi Nokihara 《Tetrahedron letters》2006,47(16):2703-2706
The parallel Sonogashira coupling reaction was carried out under copper-free condition by integrating the advantages of ionic liquids as the reaction media followed by the simultaneous-multiple Mizoroki-Heck reaction in situ by the use of a novel array reactor (SynArray-24). The device provides rapid evaluation of reactions in a short period. 相似文献
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Lingliang Long Dongdong Zhang Xiufen LiJinfang Zhang Chi ZhangLiping Zhou 《Analytica chimica acta》2013
A fluorescence ratiometric sensor for OCl− has been developed based on a novel dual fluorophore response approach. The sensor molecule contains a coumarin fluorophore and a rhodamine fluorophore, and the two fluorophores are directly linked to an OCl− recognition group. The structure of the sensor was characterized by ESI-MS, NMR, and X-ray crystallographic analysis. Upon treatment with OCl−, both fluorophores in the sensor responded simultaneously at two separate optical windows, with large enhancement of the fluorescence ratio (I578/I501) from 0.01 to 39.55. The fluorescence ratios for the sensor showed a good linearity with the concentration of OCl− in the range of 0.2–40 μM and the detection limits is 0.024 μM (S N−1 = 3). Investigation of reaction products indicated that the sensor reaction with OCl− produced two new fluorescent molecules, which were responsible for the fluorescence changes in two optical windows. In addition, the sensor showed high selectivity to OCl− over other reactive oxygen species, reactive nitrogen species, cations, and anions. The sensor has also been successfully applied to detection of OCl− in natural water samples with satisfactory recovery. 相似文献
14.
Akira YamaguchiPeng Jin Hiroshi TsuchiyamaTakao Masuda Kai SunShigeki Matsuo Hiroaki Misawa 《Analytica chimica acta》2002,468(1):143-152
Applicability of polydimethylsiloxane (PDMS) for easy and rapid fabrication of enzyme sensor chips, based on electrochemical detection, is examined. The sensor chip consists of PDMS substrate with a microfluidic channel fabricated in it, and a glass substrate with enzyme-modified microelectrodes. The two substrates are clamped together between plastic plates. The sensor chip has shown no leakage around the microelectrodes under continuous solution flow (34 μl/min). Amperometric response of the sensor chips developed in this work suggest that various types of enzyme sensors can be designed by using PDMS microfluidic channels. 相似文献
15.
Alimelli A Pennazza G Santonico M Paolesse R Filippini D D'Amico A Lundström I Di Natale C 《Analytica chimica acta》2007,582(2):320-328
In the last years a large number of different measurement methodologies were applied to measure the freshness of fishes. Among them the connection between freshness and headspace composition has been considered by gas chromatographic analysis and from the last two decades by a number of sensors and biosensors aimed at measuring some characteristic indicators (usually amines). More recently also the so-called artificial olfaction systems gathering together many non-specific sensors have shown a certain capability to transduce the global composition of the fish headspace capturing the differences between fresh and spoiled products. One of the main objectives related to the introduction of sensor systems with respect to the analytical methods is the claimed possibility to distribute the freshness control since sensors are expected to be “portable” and “simple”. In spite of these objectives, until now sensor systems did not result in any tool that may be broadly distributed. In this paper, we present a chemical sensor array where the optical features of layers of chemicals, sensitive to volatile compounds typical of spoilage processes in fish, are interrogated by a very simple platform based on a computer screen and a web cam. An array of metalloporphyrins is here used to classify fillets of thawed fishes according to their storage days and to monitor the spoilage in filleted anchovies for a time of 8 h. Results indicate a complete identification of the storage days of thawed fillets and a determination of the storage time of anchovies held at room temperature with a root mean square error of validation of about 30 min.The optical system produces a sort of spectral fingerprint containing information about both the absorbance and the emission of the sensitive layer. The system here illustrated, based on computer peripherals, can be easily scaled to any device endowed with a programmable screen and a camera such as cellular phones offering for the first time the possibility to fulfil the sensor expectation of diffused and efficient analytical capabilities. 相似文献
16.
We report the fabrication of a microfluidic chip or lab-on-a-chip integrated with a thickness-shear mode (TSM) acoustic wave sensor for muscle cell analysis. The sensor, essentially an AT-cut quartz crystal, serves as a detector for recording changes in acoustic wave properties occurring in an attached cardiomyocyte (single heart muscle cell) during its contraction and relaxation. Presumably, the changes resulted from alterations in viscoelastic properties (e.g. stiffness) of the cells. The effects of excitation electrode size, the presence of a microfluidic channel plate, and liquid loading on the sensor were first examined. Thereafter, muscle cell contraction analysis upon chemical stimuli were described. The potential of the chip for screening of cardiovascular drugs is discussed. 相似文献
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John F. Callan Joanne Ferguson Allen J.M. Huxley Aoife M. O'Brien 《Tetrahedron》2004,60(49):11125-11131
Two leading designs of fluorescent sensors are combined to yield the novel hybrid system of the ‘Fluorophore-Receptor1-Spacer-Receptor2’ format. We use 4-(dialkylaminoalkylamino)-7-nitrobenzo-2-oxa-1,3-diazoles as examples. The emission from internal charge transfer excited states in the present instances are highly responsive to N-H deprotonation as well as being quenched by intramolecular tertiary amine groups via photoinduced electron transfer (PET). When applied to pH sensing, this leads in favourable cases to two steps in the fluorescence-pH profile which can be viewed as a multi-stable photoionic device, even though single steps are more usual. The former situation is favoured when the two proton-associated equilibria are sufficiently separated on the pH scale and when the PET process is of moderate efficiency. These systems have the added feature of excitation/emission wavelengths in the visible region. As a secondary theme, we point out that caution is required when designing sensors for transition metal ions from systems with intrinsically proton-sensitive fluorescence due to receptors either integrated with or spaced from the fluorophore. 相似文献
20.
Roberto Corradini Cristina Paganuzzi Rosangela Marchelli Sara Pagliari Arnaldo Dossena Alexander Duchateau 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):625-630
Ditopic receptors based on cyclodextrins bearing a metal binding site were used as enantioselective fluorescence sensors,
which were able to generate different responses in the presence of d- or l-amino acids. The performances of the selectors as a function of their structure were evaluated, and the same analysis was
extended to other analytes. In this work, this approach is used for the enantiomers of a series of amino acid derivatives
and in particular of 2-aminocaprolactam. The results showed that the ability of these sensors to perform enantiomeric analysis
can be extended to other analytes of interest in organic synthesis such as amino acid amides and α-aminolactams. 相似文献