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1.
A benzofuran glycinamide-based chemosensor, 3-(2-([4-fluorobenzyl]amino)acetamido)benzofuran-2-carboxamide ( BGA ) was developed and synthesized for the selective and sensitive detection of Fe 3+ ions. The photophysical properties of the probe BGA were studied using UV–visible light absorption and fluorescence spectrophotometers. The chemosensor BGA showed a marked ‘on–off’ fluorescence response towards Fe 3+ ions in the presence of other metal ions in DMSO/H 2O solution (9/1, v/v). The very low limits of detection (LOD) were calculated to be 10 nM and 43 nM using UV–visible light absorption and fluorescence spectrophotometers, respectively. Job's plot analysis revealed the formation of a BGA -Fe 3+ complex with a 1:1 binding stoichiometry ratio using UV–visible light spectroscopy. The sensing mechanism was also demonstrated using density functional theory calculation. 相似文献
2.
In this study, we demonstrated a highly sensitive, selective, and reversible chemosensor for Hg 2+ determination. This chemosensor was synthesized by direct condensation of thymin‐1‐ylacetic acid with zinc tetraaminoporphyrin, which has a porphyrin core as the fluorophore and four thymine (T) moieties as the specific interaction sites for Hg 2+. The probe (4T‐ZnP) exhibited split Soret bands with a small peak at 408 nm and a strong band at 429 nm in a dimethylformamide/H 2O (7/3, v/v) mixed solvent as well as a strong emission band at 614 nm. Upon the addition of Hg 2+, the probe displayed strong fluorescence quenching due to the formation of T‐Hg 2+‐T complexes. With the aid of the fluorescence spectrometer, the chemosensor in the dimethylformamide/H 2O (7/3, v/v) mixed solvent (0.3 μM) exhibited a detection limit of 6.7 nM. Interferences from other common cations, such as Co 2+, K +, Sn 2+, Zn 2+, Cu 2+, Ni 2+, Mn 2+, Na +, Ca 2+, Mg 2+, Pb 2+, and Cd 2+, associated with Hg 2+ analysis were effectively inhibited. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
3.
A new rhodamine–ethylenediamine–nitrothiourea conjugate (RT) was synthesized and its sensing property as a fluorescent chemodosimeter toward metal ions was explored in water media. Analytical results from absorption and fluorescence spectra revealed that the addition of Hg 2+ ions to the aqueous solution of the chemodosimeter RT caused a distinct fluorescence OFF–ON response with a remarkable visual color change from colorless to pink; however, no clear spectral and color changes were observed from other metal ions including: Zn 2+, Cu 2+, Cd 2+, Pb 2+, Ag +, Fe 2+, Cr 3+, Co 3+, Ni 2+, Ca 2+, Mg 2+, K + and Na +. The sensing results and the molecular structure suggested that a Hg 2+‐induced a desulfurization reaction and cyclic guanylation of the thiourea moiety followed by ring‐opening of the rhodamine spirolactam in RT are responsible for a distinct fluorescence turn‐on signal, indicating that RT is a remarkably sensitive and selective chemodosimeter for Hg 2+ ions in aqueous solution. Hg 2+ within a concentration range from 0.1 to 25 μM can be determined using RT as a chemodosimeter and a detection limit of 0.04 μM is achieved. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
4.
The designing and development of fluorescent chemosensors have recently been intensively explored for sensitive and specific detection of environmentally and biologically relevant metal ions in aqueous solution and living cells. Herein, we report the photophysical results of alanine substituted rhodamine B derivative 3 having specific binding affinity toward Fe 3+ with micro molar concentration level. Through fluorescence titration at 599 nm, we were confirmed that ligand 3 exhibited ratiometric fluorescence response with remarkable enhancement in emission intensity by complexation between 3 and Fe 3+ while it appeared no emission in case of the competitive ions (Sc 3+, Yb 3+, In 3+, Ce 3+, Sm 3+, Cr 3+, Sn 2+, Pb 2+, Ni 2+, Co 2+, Cu 2+, Ba 2+, Ca 2+, Mg 2+, Ag +, Cs +, Cu +, K +) in aqueous/methanol (60:40, v/v) at neutral pH. However, the fluorescence as well as colorimetric response of ligand–iron complex solution was quenched by addition of KCN which snatches the Fe 3+ from complex and turn off the sensor confirming the recognition process was reversible. Furthermore, bioimaging studies against L-929 cells (mouse fibroblast cells) and BHK-21 (hamster kidney fibroblast), through confocal fluorescence microscopic experiment indicated that ligand showed good permeability and minimum toxicity against the tested cell lines. 相似文献
5.
A new fluorescent zinc (II) complex-based probe 1 encompassing a Schiff's base (E)-2-methoxy-6-((2-[5-nitropyridin-2-ylamino]ethylimino)methyl)phenol ( HL ) was designed, synthesized, and used for the highly selective detection of Cu 2+. Ligand HL and complex 1 were characterized using various spectroscopic techniques such as 1H, 13C-NMR, and FTIR spectroscopy, high-resolution mass spectronomy (HRMS), UV/visible light spectroscopy, and fluorescence studies. Ligand HL did not exhibit any considerable change in fluorescence in the presence of various cations. Notably, its Zn(II) complex 1 exhibited highly selective ‘TURN-OFF’ fluorescence signalling towards Cu 2+ that remained uninterrupted with competing analytes. Probe 1 interacted with Cu 2+ in 1:2 (1:Cu 2+) stoichiometry as estimated through a Job's plot. Moreover, the selectivity of 1 was further confirmed through the interaction of the 1 + Cu 2+ complex with some possible interfering metal ions inducing an insignificant response. Additionally, the association and quenching constant were determined to be 3.30 × 10 4 M −1 and 0.21 × 10 5 M −1 through the Benesi–Hildebrand method and Stern–Volmer plot, respectively. 相似文献
6.
A new Rhodamine B-based fluorescent probe (RBO) is successfully designed and synthesized, which is a higher selective and sensitive chemosensor for Cu 2+ than other ions. Under physiological conditions (pH = 7.0), the non emission RBO displays a rapid fluorescence increase together with a color change after addition of Cu 2+ and the detection limit is down to 28 nM, which can clearly illustrate the distribution of Cu 2+ with the help of laser scanning confocal microscope in plant tissues. Eventually, it confirmed that the Cu 2+ accumulates mostly in the vascular cylinder and very less in the epidermal cells of maize roots, which is important to understand how the plants take up, transport and store in the Cu 2+. 相似文献
7.
We report a combined approach that introduces the use of 4‐aminobenzo‐15‐crown‐5 (4AB15C5) for the detection of ferric(III) ions by colorimetric, ultraviolet (UV)–visible light absorption, fluorescence, and live‐cell imaging techniques along with density functional theory (DFT) calculations. We have found that 4AB15C5 is sensitive and selective for binding ferric(III) ions in aqueous solutions. DFT calculations using the polarizable continuum model have been used to explain the strong binding of the ferric ion by 4AB15C5 in aqueous solutions. The detection limit in the fluorescence quenching measurements was found to be as low as 50 μM for the ferric ion with a determined Stern–Volmer constant of 1.52 × 10 4 M ?1. Fluorescence intensity did not change for other ions tested, Fe 2+, Co 2+, Mn 2+, Mg 2+, Zn 2+, Ca 2+, NH 4+, Na +, and K + ions. Live‐cell fluorescence imaging was also used to check the intracellular variations in ferric ion levels. Our spectroscopic data indicated that 4AB15C5 can bind ferric ions selectively in aqueous solutions. 相似文献
8.
Divalent metal-ion transporter-1 (DMT1) is a H +-coupled metal-ion transporter that plays essential roles in iron homeostasis. DMT1 exhibits reactivity (based on evoked currents) with a broad range of metal ions; however, direct measurement of transport is lacking for many of its potential substrates. We performed a comprehensive substrate-profile analysis for human DMT1 expressed in RNA-injected Xenopus oocytes by using radiotracer assays and the continuous measurement of transport by fluorescence with the metal-sensitive PhenGreen SK fluorophore. We provide validation for the use of PhenGreen SK fluorescence quenching as a reporter of cellular metal-ion uptake. We determined metal-ion selectivity under fixed conditions using the voltage clamp. Radiotracer and continuous measurement of transport by fluorescence assays revealed that DMT1 mediates the transport of several metal ions that were ranked in selectivity by using the ratio Imax/ K0.5 (determined from evoked currents at −70 mV): Cd 2+ > Fe 2+ > Co 2+, Mn 2+ ≫ Zn 2+, Ni 2+, VO 2+. DMT1 expression did not stimulate the transport of Cr 2+, Cr 3+, Cu +, Cu 2+, Fe 3+, Ga 3+, Hg 2+, or VO +. 55Fe 2+ transport was competitively inhibited by Co 2+ and Mn 2+. Zn 2+ only weakly inhibited 55Fe 2+ transport. Our data reveal that DMT1 selects Fe 2+ over its other physiological substrates and provides a basis for predicting the contribution of DMT1 to intestinal, nasal, and pulmonary absorption of metal ions and their cellular uptake in other tissues. Whereas DMT1 is a likely route of entry for the toxic heavy metal cadmium, and may serve the metabolism of cobalt, manganese, and vanadium, we predict that DMT1 should contribute little if at all to the absorption or uptake of zinc. The conclusion in previous reports that copper is a substrate of DMT1 is not supported. 相似文献
9.
A new 2,5‐diphenyl‐1,3,4‐oxadiazole‐based derivative (L) was synthesized and applied as a highly selective and sensitive fluorescent sensor for relay recognition of Cu 2+ and S 2? in water (Tris–HCl 10 mM, pH = 7.0) solution. L exhibits an excellent selectivity to Cu 2+ over other examined metal ions with a prominent fluorescence ‘turn‐off’ at 392 nm. L interacts with Cu 2+ through a 1:2 binding stoichiometry with a detection limit of 4.8 × 10 –7 M. The on‐site formed L–2Cu 2+ complex exhibits excellent selectivity to S 2? with a fluorescence ‘off–on’ response via a Cu 2+ displacement approach. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
10.
Two BODIPY derivatives for Cu 2+ ion chemosensors containing 4-[2-(diethylamino)-2-oxoethoxy]phenyl ( BDP1) and 3,4-bis[2-(diethylamino)-2-oxoethoxy]phenyl ( BDP2) were synthesized by coupling appropriate N, N-diethyl-2-(4-formylphenoxy)acetamide and 2,4-dimethylpyrrole moieties in the presence of trifluoroacetic acid and anhydrous dichloromethane at room temperature. The binding abilities between these chemosensors and 50 equivalents of Na +, K +, Ag +, Ca 2+, Fe 2+, Ni 2+, Cu 2+, Zn 2+, Cd 2+, Hg 2+ and Pb 2+ ions were studied using UV-vis and fluorescence spectrophotometry. The results show that, compared to other ions, both the UV-vis absorption and fluorescence emission intensity of BDP2 decreased dramatically when Cu 2+ ion was added. To explain this behavior, ab initio quantum chemical calculations were performed using correlated second-order Møller-Plesset perturbation theory (MP2/LanL2DZ). The calculated orbital energies indicated that the decrease in UV-vis absorption intensity and the quenching of fluorescene emission were due to the single-electron reduction of Cu 2+ to Cu + ion. Figure Optimized structure, fluorescent spectra, frontier orbital energy diagrams and electron-transfer paths in receptor BDP2 before and after attachment to Cu 2+ ion 相似文献
11.
We prepared an aminothiourea‐derived Schiff base (DA) as a fluorescent chemosensor for Hg 2+ ions. Addition of 1 equiv of Hg 2+ ions to the aqueous solution of DA gave rise to an obvious fluorescence enhancement and the subsequent addition of more Hg 2+ induced gradual fluorescence quenching. Other competing ions, including Pb 2+, Cd 2+, Cr 3+, Zn 2+, Fe 2+, Co 3+, Ni 2+, Ca 2+, Mg 2+, K + and Na +, did not induce any distinct fluorescence changes, indicating that DA can selectively detect Hg 2+ ions in aqueous solution. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
12.
Two new twinborn benzimidazole derivates ( L and A ), which bonded pyridine via the ester space on the opposite and adjacent positions of the benzene ring of benzimidazole respectively, were designed and synthesized. Compound L displayed fluorescence quenching response only towards copper(II) ions (Cu 2+) in acetonitrile solution with high selectivity and sensitivity. However, compound A presented ‘on–off’ fluorescence response towards a wide range of metal ions to different degrees and did not have selectivity. Furthermore, compound L formed a 1:1 complex with Cu 2+ and the binding constant between sensor L and Cu 2+ was high at 6.02 × 10 4 M ?1. Job's plot, mass spectra, IR spectra, 1H‐NMR titration and density functional theory (DFT) calculations demonstrated the formation of a 1:1 complex between L and Cu 2+. Chemosensor L displayed a low limit of detection (3.05 × 10 ?6 M) and fast response time (15 s) to Cu 2+. The Stern–Volmer analysis illustrated that the fluorescence quenching agreed with the static quenching mode. In addition, the obvious difference of L within HepG2 cells in the presence and absence of Cu 2+ indicated L had the recognition capability for Cu 2+ in living cells. 相似文献
13.
Sodium dodecyl sulfate (SDS)-capped 1-pyrenecarboxaldehyde nanoparticles (PyalNPs) were prepared using a reprecipitation method in an aqueous medium and exhibited red-shifted aggregation-induced enhanced emission (AIEE). The dynamic light scattering (DLS) examination showed narrower particle size distribution with an average particle size of 41 nm, whereas −34.5 mV zeta potential value indicate the negative surface charge and good stability of nanoparticles (NPs) in an aqueous medium. The AIEE was seen at λ max = 473 nm in a fluorescence spectrum of a PyalNP suspension. In the presence of Cu 2+ ions, the fluorescence of PyalNPs quenches very significantly, even in the presence of other metal ions like Ba 2+, Ca 2+, Cd 2+, Co 2+, Al 3+, Fe 2+, Hg 2+, Ni 2+ and Mg 2+. The changes in the fluorescence lifetime of PyalNPs in the presence of Cu 2+ ions suggested that the type of quenching was dynamic. The fluorescence quenching data for the NPs suspension fitted well into a typical Stern–Volmer relationship in the concentration range 1.0–25 μg/ml of Cu 2+ ions. The estimated value of the correlation coefficient R2 = 0.9877 was close to 1 and showed the linear relationship between quenching data and Cu 2+ ion concentration. The limit of detection (LOD) was found to be 0.94 ng/ml and is far below the tolerable intake limit value of 1.3 μg/ml accepted by the World Health Organization for Cu 2+ ions in drinking water. The fluorescence quenching approach for a SDS-capped Pyal nanosuspension for copper ion quantification is of high specificity and coexisting ions were found to interfere very negligibly. The developed method was successfully applied for the estimation of copper ions in river water samples. 相似文献
14.
An asymmetrical diarylethene (1O) with a bi‐8‐carboxamidoquinoline unit was synthesized. Its photochromic and fluorescence performances on stimulation with both light and metal ions showed that the diarylethene could serve as a highly selective ratiometric fluorescent chemosensor to detect Zn 2+ ions based on internal charge transfer and chelation‐enhanced fluorescence processes. The diarylethene could selectively discriminate Zn 2+ from Cd 2+ in acetonitrile. Furthermore, Job's plots based on fluorescence titration and electrospray ionization mass spectrometry analysis showed 1 : 1 binding stoichiometry between 1O and Zn 2+. The binding constant of 1O with Zn 2+, estimated using the Benesi–Hildebrand method, and the limit of detection were 3.37 × 10 5 M –1 and 4.6 × 10 –8 mol/L, respectively. Additionally, the light and metal‐responsive fluorescence behavior of 1O was used successfully to construct a molecular logic circuit with four inputs and one output. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
15.
Naphthazarin esters (C1–C4) isolated from the roots of Arnebia euchroma are found as skilled dual chemosensors for Ni 2+ and Cu 2+ among Pb 2+, Na 2+, K 2+, Hg 2+, Mg 2+, and Ca 2+ metal ions. C1–C4 esters exhibited a red shift of 54 nm with Ni 2+ and 30 nm with Cu 2+ metal ions in absorption. There is a formation of red-shifted bands between 517 and 613 nm in the absorption spectrum of C1–C4 sensors on binding with Ni 2+ and Cu 2+ ions. The addition of Ni 2+ and Cu 2+ ions to sensors C1–C4 stimulates a remarkable color change from reddish pink to purple and light blue, respectively. These color changes can be identified with the naked eye. The significant downfield shifts of CO and OH peaks in nuclear magnetic resonance (NMR) spectrum confirm the chelation as binding mechanism. With ultraviolet–visble and NMR studies, it is found that C1–C4 esters possessed notable selectivity and sensitivity toward Ni 2+ and Cu 2+ over other metal ions. 相似文献
16.
In this study, a novel fluorescent chemosensor 1 based on chromone-3-carboxaldehyde Schiff base was synthesized and featured through nuclear magnetic resonance (NMR) and mass spectra. Spectroscopic investigation indicated that the fluorescent sensor showed high selectivity toward Zn 2+ over other metal ions and that the detection limit of 1 could reach 10 −7 M. These indicated that 1 acted as a highly selective and sensitive fluorescence chemosensor for Zn 2+. 相似文献
17.
We report the fabrication of a novel easily available turn‐on fluorescent water‐soluble polymeric chemosensor for Hg 2+ ions that was simply prepared by micellar free radical polymerization of a water‐insoluble organic rhodamine‐based Hg 2+‐recognizing monomer (GR6GH), with hydrophilic monomers acrylamide (AM) and acrylic acid (AA). The chemical structure of the polymeric sensor was characterized by FT‐IR and 1H NMR spectroscopy. The apparent viscosity average molecular weight M η of poly(acrylamide–acrylic acid) [poly(AM–NaAA)] and the water‐soluble polymeric chemosensor poly(AM–NaAA–GR6GH) were 1.76 × 10 6 and 6.84 × 10 4 g/mol, respectively. Because of its amphiphilic property, the water‐soluble polymeric chemosensor can be used as a chemosensor in aqueous media. Upon addition of Hg 2+ ions to an aqueous solution of poly(AM–NaAA–GR6GH), fluorescence enhancements were observed instantly. Moreover, other metal ions did not induce obvious changes to the fluorescence spectra. This approach may provide an easily measurable and inherently sensitive method for Hg 2+ ion detection in environmental and biological applications. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
18.
Ion‐induced change in fluorescence is a straight‐forward method for detection of toxic metal ions showing immediate response. Cadmium ions are toxic to the environment. We report in this paper a piperidine‐4‐one‐based fluorescent chemosensor of Cd 2+ ions, designed and synthesized by a simple method. The compound is characterized using infra‐red (IR) and 1H–NMR spectral techniques. The chemosensor showed Cd 2+ ion selectivity and sensitivity in aqueous solution. The stoichiometry and the binding constants were determined using fluorescence spectroscopy. Piperidine‐4‐one shows a 1:1 stoichiometric binding to Cd 2+. The limit of detection of Cd 2+ was reported. 相似文献
19.
A new ion sensor based on hybrid SiO 2‐coated CdTe nanocrystals (NCs) was prepared and applied for sensitive sensing of Cu 2+ and Ag + for the selective quenching of photoluminescence (PL) of NCs in the presence of ions. As shown by ion detection experiments conducted in pure water rather than buffer solution, PL responses of NCs were linearly proportional to concentrations of Cu 2+ and Ag + ions < 3 and 7 uM, respectively. Much lower detection limits of 42.37 nM for Cu 2+ and 39.40 nM for Ag + were also observed. In addition, the NC quenching mechanism was discussed in terms of the characterization of static and transient optical spectra. The transfer and trapping of photoinduced charges in NCs by surface energy levels of CuS and Ag 2S clusters as well as surface defects generated by the exchange of Cu 2+ and Ag + ions with Cd 2+ ion in NCs, resulted in PL quenching and other optical spectra changes, including steady‐state absorption and transient PL spectra. It is our hope that these results will be helpful in the future preparation of new ion sensors. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
20.
This paper reports the synthesis of azomethine-modified gold nanoparticles with azomethine (azomethine-AuNPs) in aqueous media, which were characterized by FT-IR spectroscopy, ultraviolet–visible spectroscopy (UV-Vis), dynamic light scattering (DLS), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The azomethine-AuNPs were employed as colorimetric for Cr3+ and Co2+ ions at pH 6.2–7.5 and 8.1–9.1, at room temperature in aqueous solution. In the presence of Cr3+ and Co2+, the azomethine-AuNPs induce aggregation of the nanoparticles. Upon aggregation, the surface plasmon absorption band red-shifts so that the nanoparticle solution appears a blue color. The sensitivity of azomethine-AuNPs towards other metal ions, Mg2+, Mn2+, Cr6+, Na+, Ni2+, Ag+, Al3+, Ca2+, Cd2+, Cu2+, Fe2+, Fe3+, Hg2+, Cd2+, K+, Co3+, Ni2+, Pb2+, and Zn2+ are negligible. This highly selective sensor allows a direct quantitative assay of Co2+ and Cr3+ with colorimetric detection limits of 83.22 and 108 nM, respectively. 相似文献
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