Selective Detection Of Cu2 Research Articles

A nano sensor for sensitive and selective detection of Cu2+ based on fluorescein: Cell imaging and drinking water analysis.

A fluorescein-based nano probe was designed and synthesized for ultra-sensitive detection of Cu2+ in aqueous solution. The formation of fluorescent organic nanoparticles confirmed by using particle size analysis and scanning electron microscopy. UV-Vis. absorption and fluorescence spectroscopy displays excellent photophysical properties of prepared nanoparticles as compared to parent molecule i.e. N-(3',6'-dihydroxy-3-oxo-3,3a-dihydrospiro[isoindole-1,9'-xanthene]-2(7aH)-yl)-1-naphthamide (FNH) in acetone. A series of 18 metal ion was examined with FNH nanoparticles (FNHNPs) to examine the change in fluorescence response. Pleasingly, only copper ion (Cu2+) shows selective and sensitive fluorescence enhancement effect, which discussed on chelation-enhanced fluorescence phenomenon. Other competing metal ions does not affect the FNHNPs fluorescence enhancement induced by Cu2+ ion. The excited state complexation through chelation-enhanced fluorescence of FNHNPs was further supported by UV-Vis. absorption and fluorescence decay titration of FNHNPs with and without the addition of Cu2+. The present investigation approach serves extremely low detection limit of 1.62 ng/mL (0.024 μM) for Cu2+ in aqueous solution. In addition, benefit of present study includes practical application for the quantitative estimation of Cu2+ in drinking water sample and intracellular cell imaging for Cu2+.

Ester appended organosilatranes: Paradigm for the detection of Cu2+, Pb2+ and Hg2+ ion

A new series of ester appended organosilatranes (5a–f) were developed for the specific and selective detection of Cu2+, Hg2+ and Pb2+ and were well characterized by various spectroscopic techniques. The newly synthesized silatranes (5a–f) were appraised for heavy metal ion binding properties using UV-vis and photoluminescent spectra. In addition the stern volmer plot confirmed the quenching phenomenon on addition of Cu2+, Hg2+ and Pb2+. Interestingly, the detection limit of 5a-f with Cu2+, 5b with Hg2+ and 5d with Pb2+ is 1.07–3.56 µM, 1.43 and 1.65 respectively. In a nutshell, the present article provides the cost-effective and promising platform for detection of these ions.

Sensitive and selective detection of Cu2+ ions based on fluorescent Ag nanoparticles synthesized by R-phycoerythrin from marine algae Porphyra yezoensis

In this study, using a natural and green protein R-phycoerythrin (R-PE) extracted from marine Porphyra yezoensis as the stabilizer and reducer, silver nanoparticles (AgNPs) were synthesized. Based on this, a highly sensitive and selective method for the detection of Cu2+ ions was developed using R-PE-AgNPs as fluorescent probe. The interactions between R-PE-AgNPs and Cu2+ ions were systematically characterized by fluorescence spectroscopy, transmission electron microscopy (TEM), elemental mapping and Fourier transform infrared (FTIR). It was found that Cu2+ ions could cause aggregation of the R-PE-AgNPs, accompanied by the greatly increased particle size. Importantly, the method offered a wide linear detection range from 0 μM to 100.0 μM with a detection limit of 0.0190 μM. Moreover, the proposed method was successfully applied to analyze Cu2+ ions in tap water and lake water samples, acquiring satisfactory recovery between 91.6% and 102.2%. Such a green, fast and cost-effective fluorimetric method of the R-PE-AgNPs probe has great potential for tracing Cu2+ ions in diverse aqueous media.

Analyte-triggered cyclic autocatalytic oxidation amplification combined with anupconversion nanoparticle probe for fluorometricdetection of copper(II).

The authors describe an upconversion nanoparticle-based (UCNP-based) fluorometric method for ultrasensitive and selective detection of Cu2+. The UCNPs show a strong emission band at 550nm under near-infrared excitation at 980nm. The principle of the strategy is that gold nanoparticles (AuNP) can quench the fluorescence of UCNP. In contrast, the addition of L-cysteine (Cys) can induce the aggregation of AuNP, resulting in a fluorescence recovery of theUCNPs. On addition of Cu2+, it oxidizes Cys to cystine and is reduced to Cu+. The Cu+ thusformedcan be oxidized cyclically to Cu2+ by dissolved O2, which catalyzes and recycles the whole reaction. Thus, the aggregation of AuNP is inhibited and the fluorescence recovered by Cys is quenched. Under the optimal condition, the quenching efficiency shows a good linear response to theconcentrations of Cu2+ in the 0.4-40nM range. The limit of detection is 0.16nM, which is 5 orders of magnitude lower than the U.S. Environmental Protection Agency limit for Cu2+ in drinking water (20μM). The method has been further applied to monitor Cu2+ levels in real samples. The results of detection are wellconsistent with those obtained by atomic absorption spectroscopy. Graphical abstract Gold nanoparticles (AuNP) as a high efficient fluorescence quenching reagent of upconversion nanoparticles (UCNP) were used in a fluorometric method for detection of Cu2+ based on acyclic catalytic oxidation amplification strategy.

Pyranine functionalized Fe3O4 nanoparticles for the sensitive fluorescence detection of Cu2+ ions

In this study, a sensitive fluorescence sensor was synthesized for the detection of Cu2+ ions based on the quenching of fluorophore. The sensor is composed of pyranine functionalized amino silane shell modified magnetite (Fe3O4) core nanostructures. The synthesized nanomaterials were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Powder Diffraction (XRD), Vibrating Sample Magnetometer (VSM) and Transmission Electron Microscopy (TEM). The fluorescent magnetic nanoparticles were analyzed by fluorescence spectroscopy. The characterization data showed that the magnetic core was highly superparamagnetic with an average particles diameter up to 10 nm. The fluorescence response of Fe3O4@-SiO2-NH2-Pyr nanosensor towards Cu2+ ions showed an enhanced and selective fluorescence quenching. Pyranine functionalized magnetic nanoparticles were found to be highly selective for Cu2+ ions without giving any response to other interfering cations and biomolecules. The nanosensor not only provided a sensitive (LOD = 6 nM), fast and selective detection of Cu2+ ions but a new fluorescent and biocompatible material with potential uses in biological and environmental fields.

Sensitive and selective detection of Cu(II) ion: A new effective 1,8-naphthalimide-based fluorescence 'turn off' sensor.

The present study reports the development of a new 1,8-naphthalimide-based fluorescent sensor V for monitoring Cu(II) ions. The sensor exhibited pH independence over a wide pH range 2.52-9.58, and indicated its possible use for monitoring Cu(II) ions in a competitive pH medium. The sensor also showed high selectivity and sensitivity towards the Cu(II) ions over other competitive metal ions in DMSO-HEPES buffer (v/v, 1:1; pH7.4) with a fluorescence 'turn off' mode of 79.79% observed. A Job plot indicated the formation of a 1:1 binding mode of the sensor with Cu(II) ions. The association constant and detection limit were 1.14 × 106 M-1 and 4.67 × 10-8 M, respectively. The fluorescence spectrum of the sensor was quenched due to the powerful paramagnetic nature of the Cu(II) ions. Potential application of this sensor was also demonstrated when determining Cu(II) ion levels in two different water samples.

A novel reaction-based fluorescent probe for sensitive and selective detection of Cu 2+

A novel reaction-based fluorescent probe (2) for Cu2+ was designed and synthesized. 2 exhibited remarkable fluorescence enhancement (65-fold) after the addition of Cu2+. Base on the absorption spectra, fluorescence spectra, ESI-MS and 1H NMR spectra analysis, the fluorescence response was attributed to Cu2+-promoted hydrolysis of the picolinate moiety to yield a highly fluorescent product, 6-acetyl-2-hydroxynaphthalene (1). Moreover, 2 not only displayed a rapid response time (within 6 min), high sensitivity (detection limit of 8.5 nM), and high selectivity for Cu2+ over other metal ions, but also could detect Cu2+ by absorption spectra, fluorescence spectra, even an obvious fluorescence color change at room temperature.

Highly sensitive and selective determination of copper(II) based on a dual catalytic effect and by using silicon nanoparticles as a fluorescent probe.

The authors describe a silicon nanoparticle-based fluorometric method for sensitive and selective detection of Cu2+. It is based on the catalytic action of Cu2+ on the oxidation of cysteine (Cys) by oxygen to form cystine and the by-product H2O2. The generated H2O2 is catalytically decomposed by Cu2+ to generate hydroxyl radicals which oxidize and destroy the surface of SiNPs. As a result, the blue fluorescence of the SiNPs is quenched. The method has excellent selectivity due to the dual catalytic effects of Cu2+, which is much better than most previously reported nanomaterial-based assays for Cu2+. Under the optimal conditions, the method has low detection limit (29nM) and a linear response in a concentration range from 0.05μM to 15μM. The method has been successfully applied to the determination of Cu2+ in spiked real water samples, and the results agreed well with those obtained by the Chinese National Standard method (GB/T 7475-1987; AAS). Graphical abstract Schematic presentation of a fluorometric method for the determination of Cu2+ based on the dual catalytic effects of Cu2+, and the oxidative effect of hydroxy radicals on the surface of silicon nanoparticles (SiNPs). The method has a 29 nM detection limit and good selectivity.

Coumarin-based tripodal chemosensor for selective detection of Cu(II) ion and resultant complex as anion probe through a Cu(II) displacement approach

In this paper, a novel tripodal fluorescent receptor based on naturally occurring coumarin was synthesized and its ionic recognition properties were fully investigated by spectroscopic techniques. As revealed by the results, tripodal 1 exhibits excellent selectivity toward copper(II) by forming a 1:1 complex with triazole N as the main binding sites. And the resulted 1·Cu2+ complex shows recognition ability toward H2PO4− by metal displacement approach. The recognition mechanism was further investigated by computer calculation.

Selective detection of Cu2+ and S2− by a colorimetric chemosensor: Experimental and theoretical calculations

A multifunctional colorimetric chemosensor 1, based on 4-(diethylamino)-2-hydroxybenzaldehyde and 2,3-diamino-5-bromopyridine, has been synthesized and characterized. Sensor 1 detected instantly both Cu2+ and S2− by the color change from pale yellow to deep yellow. The binding modes of 1 with Cu2+ and S2− were found to be the 1:1 stoichiometry through Job plot and ESI-mass spectrometry analysis, respectively. In addition, the detection limit of 1 for Cu2+ was found to be 68.6 nΜ, which was much lower than WHO guideline (31.5 µΜ) in drinking water. Importantly, sensor 1 could be used to quantify Cu2+ in water samples. Moreover, 1 exhibited a high selectivity for S2− in the presence of other anions. The sensing mechanisms of Cu2+ and S2− by 1 were explained by theoretical calculations.

Electrochemical sensor using NH2-MIL-88(Fe)-rGO composite for trace Cd2 +, Pb2 +, and Cu2 + detection

A novel electrochemical sensor was developed for the sensitive and selective detection of Cu2+, Pb2+ and Cd2+, which was based on NH2-MIL-88(Fe)-rGO composite modified glass carbon electrode (NH2-MIL-88(Fe)-rGO/GCE). The NH2-MIL-88(Fe)-rGO composite was facilely prepared by a one-step method and characterized by SEM, XRD, Raman spectrum and electrochemical methods. The stepwise GCE modified process was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of Cu2+, Pb2+ and Cd2+ ions on the NH2-MIL-88(Fe)-rGO/GCE were explored by differential pulse anodic stripping voltammetry (DPASV). It was found that NH2-MIL-88(Fe)-rGO was capable of adsorbing Cu2+, Pb2+ and Cd2+ ions from aqueous solutions and the NH2-MIL-88(Fe)-rGO/GCE could enhance the electrochemical responses of Cu2+, Pb2+ and Cd2+ effectively. Important operational parameters such as electrolyte pH and deposition time were investigated and optimized for the determination of trace Cu2+, Pb2+ and Cd2+ ions. Under the optimum conditions, the proposed electrochemical sensor had a linear range of 0.005––0.3μM for Cd2+, 0.01–0.3μM for Pb2+ and 0.005–0.05μM for Cu2+, respectively. The limits of detection (LODs) are 4.9nM for Cd2+, 10nM for Pb2+ and 3.6nM for Cu2+, respectively. The proposed method has been successfully applied to determine three metal ions in water samples. The developed sensor promises simple preparation, fast operation, good sensitivity and excellent reusability, showing great potential for monitoring of water quality.

A facile fluorescent probe with a large Stokes shift for sequentially detecting copper and sulfide in 100% aqueous solution and imaging them in living cells

The selective detection of Cu2+ and S2− in pure water systems is very challenging. To address this problem, we here present a novel fluorescent probe CF536 for the reversible detection of Cu2+ and S2− in a 100% aqueous solution via a displacement approach based on fluorescence quenching and the ESIPT mechanism, and characterized by IR, NMR, HRMS and X-ray analysis. The introduction of Cu2+ (1.0 equiv.) to the aqueous solution of CF536 led to quenching of the intense green fluorescence within 2min. On the addition of S2− (3.0 equiv.), the emission of the ESIPT probe soon recovered from the CF536-Cu2+ system due to the abolishment of paramagnetic Cu2+. The fluorescence “ON-OFF-ON” cycle can be repeated a minimum of 5 times by the alternate addition of Cu2+ and S2−, implying that CF536 is a renewable dual-functional probe. The probe displayed high selectivity, a rapid response time, excellent water solubility due to introduction of the extremely hydrophilic trihydroxyl group and outstanding anti-interference ability for its large Stokes shift of 101nm (λabs=435nm, λem=536nm), thus making the method highly suitable for bioimaging. The probe CF536 was successfully used for fluorescent imaging of copper and hydrogen sulfide in living cells.

Iodine-Mediated Etching of Triangular Gold Nanoplates for Colorimetric Sensing of Copper Ion and Aptasensing of Chloramphenicol.

A colorimetric method for fast, simple, and selective detection of Cu2+ was developed using I--mediated etching of triangular gold nanoplates (AuNPLs). The method was based on our finding that Cu2+ efficiently promoted this etching in the presence of SCN-. The etching process was accompanied by a dramatic color change from blue to red, allowing for visual and spectroscopic detection of Cu2+ with detection limits of 10 and 1 μM, respectively. When molecular recognition by a DNA aptamer was incorporated into this method, visual detection of chloramphenicol was also achieved with a detection limit of 5 μM.

Spirohydrazine rhodamine as a fluorescent chemodosimeter for the selective detection of Cu(II) ions and its application in live cell imaging

A rhodamine-based fluorescent chemdosimeter SHR for Cu2+ has been developed based on the spirocyclic ring-opening mechanism. SHR is colorless and nonfluorescent due to intramolecular spirocyclization. Upon incubation with Cu2+ in aqueous media, a highly efficient ring opening of SHR occurs via Cu2+-promoted phenylhydrazine oxidation, causing a dual chromogenic and fluorogenic response. The fluorescent intensity at 580nm increases linearly with Cu2+ concentration and as low as 10nM of Cu2+ can be readily detected. The proposed chemodosimeter shows high selectivity toward Cu2+ over other metal ions and proves to be able to image Cu2+ levels in live cells.

A simple and facile colorimetric chemosensor for selective detection of Cu2+ ion in aqueous solution

In this paper the chemical sensing ability of aromatic salicylideneaniline Schiff-base (ASASB), synthesized solvent-free mechanochemically and characterized, was assessed via UV-Vis spectroscopic method together with naked-eye detection. Metal ions in aqueous medium from s, p and d-block elements were investigated based on chelation-induced colorimetric chemosensing. The result revealed that ASASB can be used as a new colorimetric chemosensor for selective detection of Cu 2+ ion in aqueous solution. KEY WORDS : Metal ion, Schiff-base, Colorimetric chemosensor, Mechanochemistry Bull. Chem. Soc. Ethiop. 2017 , 31(1), 31-38. DOI: http://dx.doi.org/10.4314/bcse.v31i1.3

Carbazole-azine based fluorescence 'off-on' sensor for selective detection of Cu2+ and its live cell imaging.

A new carbazole-azine based fluorescent sensor was synthesized and characterized. The selectivity of the sensor for Cu2+ over other counter ions in a dimethyl sulfoxide/H2 O mixture was shown through enhancement in fluorescence - an off to on transformation. The specificity of the probe towards Cu2+ was evident in ultraviolet/visible, fluorescence, Fourier transform infrared and mass studies. Application of the probe in the cell imaging and cytotoxicity of living cells is illustrated.

A colorimetric and fluorescent chemosensor for selective detection of Cu2+ based on a new diarylethene with a benzophenone hydrazone unit.

A new photochromic diarylethene based on benzophenone hydrazone has been synthesized. Its photochromic and fluorescent properties changed upon alternating irradiation with UV/Vis light and adding Cu2+ /EDTA in methanol, which showed that the diarylethene could be served as a colorimetric and fluorescent chemosensor for selective detection of Cu2+ based on internal charge transfer processes. The colorimetric and turn-off fluorescent selective detection of Cu2+ was attributed to the 2:1 complex of the diarylethene and Cu2+ . The binding constant (Ka) was 1.53×104 L mol-1 and the limit of detection of the diarylethene for Cu2+ was calculated to be 1.45×10-6 mol L-1 . In addition, the metal-responsive photochromic behavior of diarylethene was applied successfully to the construction of a molecular logic circuit.

11-Mercaptoundecanoic acid functionalized gold nanoclusters as fluorescent probes for the sensitive detection of Cu2+ and Fe3+ ions

Metal ions are physiologically essential, but excessive metal ions may cause severe risk to plants and animals. Here, we prepared gold nanoclusters (Au NCs) protected by 11-mercaptoundecanoic acid (11-MUA), which have excellent fluorescence properties for the detection of metal ions. The results showed that the copper ions (Cu2+) and iron ions (Fe3+) in the solution have obvious quenching effect on the fluorescence intensity of Au NCs. The detection range of Fe3+ was 0.8–4.5μmol/L (R2=0.992) and 4.5–11.0μmol/L (R2=0.997). And Cu2+ has a lower linear range (0.1–1.0μmol/L, R2=0.993). When EDTA was added into the reaction system, it was observed that the quenching effect of Cu2+ and Fe3+ on Au NCs showed different phenomenon. Then, the effect of metal ions on the fluorescence of Au NCs was investigated. The selective detection of Cu2+ was achieved by EDTA masking of Fe3+. In addition, we realized the metal ions detection application of Au NCs in the serum

Selective detection of Cu2 + and Co2 + in aqueous media: Asymmetric chemosensors, crystal structure and spectroscopic studies

Two new azo-azomethine receptors, H2L1 and H2L2, containing hydrazine, naphthalene and different electron withdrawing groups, Cl and NO2, have been designed and synthesized for qualitative and quantitative detection of Cu2+ and Co2+ in aqueous media. The crystal structure of H2L1is reported. The H2L1was used as a chemosensor for selective detection of trace amount of Cu2+ in aqueous media. H2L2 was also applied to naked-eye distinction of Cu2+ and Co2+ from other transition metal ions in aqueous media. Detection limit of Cu2+ is 1.13μM and 1.26μM, in water, for H2L1 and H2L2, respectively, which are lower than the World Health Organization (WHO) recommended level. The binuclear Cu2+ and Co2+ complexes of the receptors have been also prepared and characterized using spectroscopic methods and MALDI-TOF mass analysis. Furthermore, the binding stoichiometry between the receptors upon the addition Cu2+ and Co2+ has been investigated using Job's plot. Moreover, the fluorescence emission spectra of the receptors and their metal complexes are also reported.

Selective detection of copper ion in water by tetradentate ligand sensor

Abstract Tetradentate ligand, 3,5-bis(((2-hydroxynaphthalen-1-yl)methylene)amino)benzoic acid (3,5-BHNMABA), was synthesized for the selective detection of copper ion. The fluorescence of the ligand in solution was quenched about 72% by Cu(II) and about 18% by Fe(II), but it was scarcely influenced by the existence of other metal ions. The ligand was chemically bound on self-assembled monolayer on indium tin oxide electrode. The as-prepared electrode exhibited the electrochemical recognition ability for metal ions: Cu(II) could be selectively caught to 3,5-BHNMABA ligand on the electrode, but Fe(II) and other metal ions did not display electrochemical response. Results indicate the selective coordination linkage of Cu(II) with the ligand both in solution and on electrode, being different from other ions. It can be concluded that the 3,5-BHNMABA-functionalized electrode is a favorable sensor for the selective detection of Cu(II) in water.