Selective Detection Of Copper Ions Research Articles

An electrochemical sensor for highly sensitive detection of copper ions based on a new molecular probe Pi-A decorated on graphene

In this paper, a new electrochemical sensor based on a new fluorescent probe N-(2-(1-(p-tolyl)-1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)picolinamide (Pi-A) decorated reduced graphene oxide (RGO) modified glassy carbon electrode (GCE) was developed for highly selective detection of copper ions using the electrochemical method.

Colorimetric sensor for highly sensitive and selective detection of copper ion

Colorimetric detection of Cu2+based on the inhibiting effect of Cu2+on the reaction ofl-cysteine with the established probe Cy-NB.

A highly sensitive and selective fluorescent sensor for detection of copper ions based on natural Isorhamnetin from Ginkgo leaves

A natural isorhamnetin-based fluorescent sensor for highly sensitive and selective detection of copper ions had been studied. The fluorescent sensor isorhamnetin (Iso) after binding to Cu2+ ions in pH 7.40 buffer solution generated quenching in fluorescent emission intensity. The binding constant value was obtained 1.79×106. The sensor Iso can be applied to the quantification of Cu2+ ion with a linear range of 1.0×10−8–1.9×10−6molL−1, the detection limit of 4.0×10−9molL−1, and the reproducibility of the sensor is good. The sensor showed high selectivity toward Cu2+. As a result, the isorhamnetin fluorescent sensor was successfully applied for determination of Cu2+ in rivers, lakes, vegetables and fruits with good recovery.

A new fluorescence chemosensor for selective detection of copper ion in aqueous solution

A new fluorescent chemosensor based upon 2,5-diphenylfuran and di(2-picolyl)amine (DPA) was designed and synthesized. Its structure was confirmed by single crystal X-ray diffraction and its photophysical properties were studied by absorption and fluorescence spectra. This compound can be used to determine Cu2+ ion with high selectivity among a series of cations in aqueous DMSO. This sensor forms a 1:1 complex with Cu2+ and displays fluorescent quenching.

Biomimetic synthesis of needle-like fluorescent calcium phosphate/carbon dot hybrid composites for cell labeling and copper ion detection.

Herein, we report a biomimetic method to synthesize needle-like calcium phosphate (CaP) with dimensions of ∼130 nm length and ∼30 nm width using carbon dots (CDs) and sodium carboxymethylcellulose as dual templates. In addition to acting as the template, the CDs enable the CaP/CDs hybrid composites to emit blue fluorescence under UV excitation. Moreover, the prepared CaP/CDs exhibited a negligible cytotoxicity towards HeLa cells. The potential of these CaP/CDs as a fluorescent probe for cell labeling was tested. In addition, it was demonstrated that the CaP/CDs were capable of selective detection of copper ions in drinking water.

A natural quercetin-based fluorescent sensor for highly sensitive and selective detection of copper ions

A natural quercetin-based fluorescent sensor for highly sensitive and selective detection of copper ions has been studied.

An ultrasensitive and selective turn-off fluorescent nanoprobe for the detection of copper ions

In this study, a novel approach for sensitive and extremely selective detection of copper ions has been developed based on fluorescence resonance energy transfer (FRET) between AuNPs as an acceptor and fluorescein isothiocyanate (FITC) as a donor.

Tuning plasmon absorption of unmodified silver nanoplates for sensitive and selective detection of copper ions by introduction of ascorbate

Abstract Silver nanoplates as novel optical sensors for Cu 2+ detection have been demonstrated. Silver nanoplates are synthesized via previous H 2 O 2 –NaBH 4 cyclic oxidation–reduction reactions. With introduction of ascorbate as mild reductants, Cu 2+ ions are reduced into Cu + and the Cu + is further reduced to Cu, which is deposited on the surface of the silver nanoplates. The deposition of the Cu on the surface of the silver nanoplates allows a significant red-shift of their plasmon absorption. Therefore, trace Cu 2+ can be detected. The shift of the plasmon absorption wavelength of silver nanoplates is proportional to the Cu 2+ concentration over a range of 40–340 μmol L −1 with a limit of detection of 9.0 μmol L −1 . Moreover, such silver nanoplate-based optical sensors provide good selectivity for Cu 2+ detection, and most other metal ions do not disturb its detection. Moreover, the practicality of the proposed sensor was tested. This Cu 2+ assay is advantageous in its simplicity, selectivity, and cost-effectiveness.

Thermally treated bare gold nanoparticles for colorimetric sensing of copper ions

We demonstrate a sensitive and rapid colorimetric assay for selective detection of copper ions based on the strong coordination between Cu(II) ions and the tetrahydroxyaurate anions [Au(OH)4]− on the surface of thermally treated bare gold nanoparticles (GNPs). The method for making the unmodified GNPs is simple and results in a nanomaterial with a highly specific response to Cu(II). The thermal treatment of the bare GNPs and the recognition of Cu(II) ions is accomplished in a single step within 5 min. The presence of Cu(II) causes the color to change from red to purple-blue. The limit of detection (LOD) is 0.04 μM of Cu(II) when using UV–vis spectrometry and ratioing the absorbances at 650 and 515 nm, respectively. The method also is amenable to bare eye (visual) inspection and in this case has an LOD of 2.0 μM of Cu(II).

Conjugation-induced fluorescence labelling of mesoporous silica nanoparticles for the sensitive and selective detection of copper ions in aqueous solution

A newly developed fluorescent “on–off” chemosensor presents high selectivity towards Cu2+ with detection limit as low as 0.28 μM.

Sensitive and Selective Detection of Copper Ions with Highly Stable Polyethyleneimine-Protected Silver Nanoclusters

Copper is a highly toxic environmental pollutant with bioaccumulative properties. Therefore, sensitive Cu(2+) detection is very important to prevent over-ingestion, and visual detection using unaugmented vision is preferred for practical applications. In this study, hyperbranched polyethyleneimine-protected silver nanoclusters (hPEI-AgNCs) were successfully synthesized using a facile, one-pot reaction under mild conditions. The hPEI-AgNCs were very stable against extreme pH, ionic strength, temperature, and photoillumination and could act as sensitive and selective Cu(2+) sensing nanoprobes in aqueous solutions with a 10 nM limit of detection. In addition, hPEI-AgNCs-doped agarose hydrogels were developed as an instrument-free and regenerable platform for visual Cu(2+) and water quality monitoring.

Sensitive and Selective Detection of Copper Ions Based on the Aggregation of Chitosan-Stablized Silver Nanoparticles

In this contribution, we present a simple and sensitive method for detecting Cu2+ based on the Cu(2+)-induced aggregation of silver nanoparticle (AgNPs) capped with chitosan. Chitosan could be adsorbed on the surface of AgNPs, and keep AgNPs against aggregation. However, in the presence of Cu2+, AgNPs aggregate again, the absorption decreases, and the color changes from yellow to colorless, which is due to the coordination of Cu2+ and chitosan. The depressed intensity (deltaA) is in proportion to the concentration of Cu2+ over the range of 3.33-40.0 microM with the limit of detection (3sigma) of 10.25 nM, the recovery of 92.60-104.20% and R.S.D. of 0.94-4.62%. The advantages of this method are simple, sensitive and low cost.

Electrochemical Detection of Copper Using a Gly-Gly-His Modified Carbon Nanotube Biosensor

Diazonium ion chemistry has been used to electrochemically graft aminophenyl layers onto p-type silicon (100) substrates. A condensation reaction was used to immobilise single-walled carbon nanotubes with high carboxylic acid functionality directly to this layer. The surface immobilised carbon nanotubes were then modified with the tripeptide Gly-Gly-His for the selective detection of copper ions in aqueous environments. The stepwise assembly and sensitivity of this biosensor to copper was characterised by X-ray photoelectron spectroscopy and differential pulse voltammetry, respectively. The ability to detect copper ion concentrations down to 1 μM was demonstrated. As this biosensor combines the advantages of a silicon substrate for easy integration into sophisticated electrical and electronic devices, diazonium salt derived films for stability in aqueous environments and carbon nanotubes for desirable electrochemical properties, it is expected to have important future applications in environmental sensing.

Development of an aminocarboxylic acid-modified infrared chemical sensor for selective determination of copper ions in aqueous solutions

An evanescent wave infrared chemical sensor for the sensitive and selective detection of copper ions in aqueous solutions is described. Because copper ions have no vibrational features, a band-shifting technique was utilized to produce the analytical signal. To enhance the sensitivity of the detection process, a three-step procedure was employed to prepare acidified tris(2-aminoethyl)amine (ATAA) phase on an evanescent wave sensing element. This sensing phase has a chemical structure similar to that of ethylenediamine tetraacetic acid (EDTA), a common chelating agent for metal ions. After formation of complex with copper ions, the shifts in the absorption bands of the ATAA phase were used for quantitation. An additional four sensing phases having chemical structures related to that of EDTA were synthesized to compare their performances for detection of copper ions. The synthetic sensing phases are highly stable in water and insensitive to changes in solutions at pH greater than 4. ATAA was the most sensitive of the phases tested, probably because of the accessibility and flexibility of the functional groups in the ATAA phase. To explore these systems in greater detail and to optimize detection, the effects of parameters such as the buffer concentration, the pH of the sample solution, and the matrix effect on response time and linearity of detection were examined. The analytical signals for copper ions were similar – and highly selective – when the pH of the solution was between 5 and 6.5. For a detection time of 5 min, these signals were linear for concentrations up to 200 μM with a detection limit ca. 3 μM.

Selective detection of copper ions in aqueous solution based on an evanescent wave infrared absorption spectroscopic method.

A new infrared sensing scheme based on an evanescent wave was proposed in this work for selective detection of copper ion in aqueous solutions. This sensing scheme is based on the band-shifting technique to overcome the limitation that metal ions do not absorb IR radiation. To demonstrate that the proposed mechanism is feasible, both theoretical considerations and practical examination of copper ions in aqueous solutions were investigated. The IR sensor was constructed by surface modification with L-(-)proline to selectively interact with copper ions by formation of stable square-planar complexes. After complexation, the absorption bands of the immobilized L-(-)proline exhibits a band shift and could be used to monitor the quantity of metal ions in aqueous solutions. To immobilize L-(-)proline on the surface of a sensing element and increase the stability of the modified phase in aqueous solutions, poly(vinylbenzyl chloride) was coated onto the sensing element for further immobilization of L-(-)proline. A sensitive and a water-stable L-(-)proline phase was obtained. This sensing phase is selective and sensitive to copper ions due to the large formation constant between the copper ions and L-(-)proline. Factors, such as the copper ion concentration, response time, solution pH, long-term stability, regeneration efficiency, and the matrix effect, were investigated. Results indicated that the pH effect was significant but could be controlled by buffering the sample solutions. Using the optimal conditions found in this work, the detection limit could be lower than 0.7 microM and the linear regression coefficients in standard curves could be higher than 0.99 for a concentration range from 5 to 200 microM.

A dansylated peptide for the selective detection of copper ions.

A new peptidyl fluorescent chemosensor for the selective detection of copper ions was studied.