共查询到20条相似文献,搜索用时 15 毫秒
1.
A chemosensor is reported with high sensitivity and selectivity for detection of fluoride anion. The recognition mechanism is attributed to a fluoride-triggered disruption of the hydrogen bond between imidazole and naphthalimide moieties, resulting in a noncoplanar geometry with low fluorescence. 相似文献
2.
Jie Ma Yulan Zeng Luliang Yan Bingkun Chen Mengya Sun Zhenhua Liu 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):582-586
AbstractA fluorescent sensor TPE-TSC with aggregation induced emission (AIE) characteristic is synthesized for detecting Hg2+ by attaching thiosemicarbazide (TSC) unit into tetraphenylethylene (TPE) group. TPE-TSC exhibits intense green emission in DMSO/H2O (V:V?=?1:9) solution with the formation of the aggregation. TPE-TSC shows outstanding fluorescence quenching toward Hg2+ over other metal ions due to the formation of complex TPE-TSC/Hg2+ with a 2:1 binding ratio. The detection limit of TPE-TSC for Hg2+ is 1?×?10?5 mol·L?1. 相似文献
3.
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
4.
The optical carbon dioxide sensor is prepared by covering a pH sensor based on fluorescence with a CO2-permeable membrane and contacting the pH-sensitive membrane with a reservoir of hydrogen carbonate. As carbon dioxide diffuses across the membrane it causes a chnage in pH which is detected by measuring the change in fluorescence from the base form of the pH-sensitive fluorescentdye. The usable range of response depends on the concentration of hydrogen carbonate in contact with the membrane. The sensor also responds to sulfide and sulfite. 相似文献
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A colorimetric sensor based on dipyrromethane(donor)-7,7′,8,8′-tetracyanoquinodimethane (acceptor) charge-transfer compound depicts excellent selectivity for naked-eye as well as spectrophotometric determination of F− even in co-existence with other halide ions (Cl−, Br− and I−). The sensing mechanism is ascribed to the interrupted charge-transfer between donor-acceptor in the presence of F−. The sensing on solid support mimics the solution sensing process supported by the reflectance values. Thus this compound has potential for practical applications. 相似文献
7.
Tetra-dansylated diphenyl glycoluril has been synthesized and evaluated for ionic recognition. The synthesized molecular receptor shows selective response to silver ions as determined through the enhancement of fluorescence intensity. 相似文献
8.
Zhuang X Liu W Wu J Zhang H Wang P 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1352-1355
A novel visible colorimetric sensor (L1) with high selectivity for fluoride ion based on coumarin has been synthesized by a simple modification of our earlier report. The chemosensor L1 shows an obvious color change from yellow to blue upon addition of fluoride ion with a large red shift of 145 nm in acetonitrile, and without interference of other anions such as Cl-, Br-, I-, NO3-, H2PO4-, HSO4-, and AcO-. The investigation of 1H NMR spectrum titration indicates the proposed mechanism is that F- first establishes a hydrogen bonding interaction with L1, and then the formation of [F-H-F]- induces deprotonation. 相似文献
9.
LV YongJun XU Jian GUO Yong & SHAO ShiJun Key Laboratory of Chemistry of Northwestern Plant Resources Key Laboratory for Natural Medicine of Gansu Province Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou China State Key Laboratory for Oxo Synthesis Selective Oxidation China Graduate University of the Chinese Academy of Sciences Beijing China 《中国科学B辑(英文版)》2011,(5)
A boradiazaindacenes (BODIPY)-phenol conjugate,1,can act as a colorimetric and fluorometric sensor for sensitive and se-lective measurement of F-over AcO-and H2PO-4 in CH3CN. Sensor 1 gives response to F-in a 1:1 ratio via the deprotonation of the phenolic OH proton,which results in color change from pale yellow to light green and quenching of bright green fluo-rescence. 相似文献
10.
Gao F Tang L Dai L Wang L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,67(2):517-521
We have synthesized dual-fluorophore-doped core-shell silica nanoparticles used as ratiometric pH sensor. The nanoparticles were prepared with a reverse microemulsion technique by simultaneously encapsulating two different fluorophores, the pH-sensitive dye fluorescein as a pH indicator and the pH-insensitive dye phenosafranine as an internal reference for fluorescence ratiometric measurement, into silica shell. The nanoparticles prevent the fluorescence dyes leaching from the silica matrix when immersed inside water. The hydrophilic silica shells were made by hydrolysing and polymerizing tetraethoxysilane (TEOS) in water-in-oil microemulsion. The fluorescence intensity ratio of the two dyes varied linearly as a function of pH in the range from 4.0 to 8.0. The sensor was also applied to measure pH of real water samples. The results are in good agreements with that using the conventional glass electrode method. The as-prepared fluorescent nanoparticles showed rapid response, excellent stability and high reproducibility as pH sensors. 相似文献
11.
A selective optical chemical sensor for 2,6-dinitrophenol based on fluorescence quenching of a novel functional polymer 总被引:1,自引:0,他引:1
A bifurcated optical fiber based chemical sensor for continuous monitoring of 2,6-dinitrophenol (2,6-DNP) has been proposed based on the reversible chemical reaction between a novel functional poly(vinyl chloride) (PVC) as the sensing material and the analytes. The functional PVC (FPVC), containing a fluorescent curcumin moiety, was synthesized by the nucleophilic substitution of a fraction of the chlorine atoms bound to the PVC backbone by curcumin. When plasticized in a membrane of 5 μm thickness, FPVC extracts 2,6-DNP from aqueous solution into the bulk membrane phase and reacts with the analyte to form a complex with low fluorescence efficiency through hydrogen bonding. Formation of the complex gave a significant fluorescence quenching which is suitable for signalling the occurrence of the host-guest interaction. At pH 3.50, the sensor exhibits a dynamic detection range from 2.5 × 10−6 to 7.0 × 10−3 mol L−1 with a limit of detection of 1.0 × 10−6 mol L−1. As 2,6-DNP can provide an optimal space geometry matches to the formation of hydrogen bonds, the sensor shows excellent selectivity for 2,6-DNP over other nitrophenols. The forward and reverse response time (t95) of the sensor both was within 1 min. The repeatability, reproducibility, and lifetime of the sensor were also satisfied. The sensor was applied to determine 2,6-DNP in water samples successfully. 相似文献
12.
Sun MZ Wu FY Wu YM Liu WM 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(3):814-817
A novel ditopic chromogenic receptor, N-5-(8-hydroxy)quinoline-N'-4'-nitro-phenyl thiourea (1), was synthesized. The metal complex 1-Hg(2+) showed sensitive and highly selective responses to F(-) over other anions such as CH(3)CO(2)(-), H(2)PO(4)(-), HSO(4)(-) and Cl(-). 1-Hg(2+)-F(-) complex formed, which promoted the intramolecular charge transfer and led to a dramatic spectral change. The color of 1-Hg(2+) solution changed from colorless to red upon addition of F(-). Thus, a colorimetric assay of F(-) was developed in acetonitrile by naked-eye detection. F(-) behaved linearly in the 8.0 x 10(-6) to 2.0 x 10(-5) mol L(-1) concentration range with LOD as 1.4 x 10(-6) mol L(-1). 相似文献
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Kim TH Choi MS Sohn BH Park SY Lyoo WS Lee TS 《Chemical communications (Cambridge, England)》2008,(20):2364-2366
The benzoxazole derivative gelator forms a stable DMF/toluene cosolvent gel with dramatically enhanced fluorescence emission compared to its mother solution. The translucent colorless gel was changed to a solution with strong greenish fluorescence in the presence of fluoride anion with disruption of the gel structure. 相似文献
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A new anthracene derivative bearing two phenylboronic acid groups at the 1,8-positions was prepared and its binding properties towards sorbitol, xylitol, fructose, glucose and galactose have been studied using fluorescence analysis. 相似文献
17.
In a search for new type pH sensing fluorophores, the possibility of using the proton "off-on" switch behaviour of naphthalimide derivatives for optical pH sensor preparation has been explored. A new compound, N-allyl-4-(4[prime or minute]-methyl-piperazinyl)-1,8-naphthalimide (AMPN), was synthesized. The enhancement of fluorescence of AMPN with the increase of hydrogen ion concentration is based on arresting photo-induced electron transfer to the naphthalimide fluorophore from aliphatic amine group after its protonation. The Stokes Shift of the proposed type of pH sensing fluorophore is significantly larger than that of the fluorescein counterparts. To avoid the leakage of the fluorophore, AMPN was photo-copolymerized with 2-hydroxyethyl methacrylate and acrylamide on the glass surface. The fluorescence intensity of membrane contacted with a pH 3.50 buffer is 4.7 times of that for pH 12.00 buffer solutions. The proposed pH sensor is not susceptible to ionic strength and shows good selectivity, repeatability and short response time. The membrane shows a good stability with a lifetime over two months. The sensor can be used for the determination of pH in the range of pH 4.5-9.0, without interference of most commonly co-existing inorganic ions and some organic species. The sensor has been applied to the analysis of urine samples. 相似文献
18.
采用水热法合成了纳米氧化锌-氧化石墨烯复合材料,并基于该复合材料构制了一种新型双酚A传感器,研究了该传感器的电化学行为。结果表明,在含8.0×10-5mol/L CTAB的p H 7.0磷酸盐缓冲液中,双酚A在0.573V处出现1个不可逆的氧化峰,具有良好的电化学响应;其氧化峰电流与浓度在1.0×10-8~4.0×10-5mol/L范围内呈良好的线性关系,检出限为5.0×10-9mol/L;对模拟环境水样中双酚A进行3次平行测定的回收率在96.3%~101.9%之间,相对误差在1.2%~3.8%范围内。该传感器具有灵敏度高、线性范围宽的特点。 相似文献
19.
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
20.
Jianwei Li Hai Lin Zunsheng Cai Huakuan Lin 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,72(5):1062-1065
A new and simple salicylaldehyde-based sensor 1 designed for fluoride sensing has been investigated in DMSO and even in the 9/1 DMSO/H2O (v/v) mixtures. The affinity constants of receptor 1 for anionic species in the 9/1 DMSO/H2O (v/v) reveal that it is sensitive to F. Also, the color changes induced by anions can provide a way of detection by ‘naked-eye’. These result can be substantiated by the spectrum changes upon the addition of 25 equiv. anions to 1 in the 9/1 DMSO/H2O solution. The further insights to the nature of interactions between the sensor 1 and F− were investigated by 1H NMR titration experiments in 9/1 DMSO-d6/H2O (v/v). In addition, the proposed binding mode between 1 and F− was suggested. 相似文献