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Here we present an analytical method for Cu isotopic measurement using standard-sample bracketing on a Nu Sapphire multi-collector inductively coupled plasma mass spectrometer. The effects of Cu concentration and HNO3 molarity mismatch between the standard and the sample, as well as the presence of matrix elements have been evaluated. Intermediate precision of better than ±0.030‰ for δ65Cu (2SD) was routinely obtained on NIST SRM 3114 and NWU-Cu-A. Accurate measurements were achieved when CNa/CCu < 0.5, CTi/CCu, CFe/CCu and CCo/CCu < 1, CNi/CCu < 3 and CZn/CCu < 10. High-precision Cu isotopic data were determined for nineteen geological reference materials, including igneous rocks, sedimentary rocks, metamorphic rocks and chalcopyrite, with an overall range of ∼0.44‰ (−0.056‰ to 0.384‰), nearly 15 times the current analytical precision. The Cu isotopic data of these reference materials can be used for future interlaboratory comparisons. [ABSTRACT FROM AUTHOR]

Copper and its production process are crucial in the quest to achieve decarbonization of energy sources and electromobility. The quantification of mineral species in copper ores in real-time is important for monitoring and improving the performance of the process. In this work the capability of laser-induced breakdown spectroscopy (LIBS) is expanded for rapid determination of the key mineral species namely bornite (Cu5FeS4), chalcocite (Cu2S), chalcopyrite (CuFeS2), covellite (CuS), enargite (Cu3AsS4), molybdenite (MoS2) pyrite (FeS2), quartz (SiO2), and iron oxides (FexOy) in bulk copper concentrates. Multivariate calibration techniques such as partial least squares regression (PLSR), artificial neural network regression (ANNR) and multivariate curve resolution-alternating least squares (MCR-ALS) were compared as quantification approaches. Moreover, prediction accuracy errors agree with those obtained by standard mineralogical techniques such as SEM-MLA. [ABSTRACT FROM AUTHOR]

The reaction between 2,5-bis(diphenylphosphinomethyl)pyrrole and Me3SiN3 gave the new pyrrole-based bis(phosphinimine) L1H in an excellent yield. L1H reacts with [CuCl(COD)]2, AgBF4, or AgOTf to give the corresponding two-coordinate mononuclear ionic complex formulated as [M{(L1H)-κ2N,N}]+[X]− where M = Cu and Ag; X = [CuCl2], BF4 or OTf. Their single crystal X-ray diffraction studies confirmed the two-coordinate geometry formed by the chelate bonding mode of L1H. These 10-membered metalacycles exhibit planar chirality and were also characterized by spectroscopic methods. In addition, in all three structures, there exists a hitherto unknown π-interaction between the pyrrole ring atoms and metal, represented as η2-(Cα–N) in the copper(I) complex, and η3-(Cα–N–Cα′) in the silver(I) complexes. These weak interactions were supported by DFT calculations in terms of their electron densities, non-covalent interaction plots and the decrease in the aromaticity of the pyrrole ring. [ABSTRACT FROM AUTHOR]

Cu isotopic analysis can provide valuable insight when investigating Wilson's disease (WD), but one of the problems related to this type of study is that usually low sample volumes are available and/or low Cu concentrations are found in these samples. This paper presents a new approach for Cu isotope ratio determination that requires only 1 μL of pre-treated serum sample per replicate (after Cu separation and preconcentration to a Cu concentration range between 0.3 and 4 mg L−1). Cu determination was carried out by direct μ-injection of 1 μL of pretreated serum samples into an ICP-MS, offering a LOD of 3 μg L−1. For Cu isotopic analysis, the method presented is based on micro-volume deposition on a pure silicon wafer and subsequent ablation analysis by fsLA-MC-ICP-MS. Cu isotopic analysis of NIST 3114 at 1 mg L−1 Cu concentration with the self-bracketing method provided average δ65Cu values of −0.01 ± 0.19‰ (2SD) and an internal precision value of 517 ppm. This method was deployed for the analysis of serum samples from WD patients under different treatments, as well as healthy newborns and patients with other liver disorders. The results seem to link decreased δ65Cu values to Cu release from the liver, further demonstrating the potential of this type of analysis in the biomedical context. [ABSTRACT FROM AUTHOR]

Attempts to prepare a supramolecular M4L2 box involving two tetra-bipyridyl calix[4]arene units and four copper(I) cations afforded, in fact, complex 2 for which, in the solid state, X-ray diffraction analysis showed that the stoichiometry is indeed M4L2, with the two calixarene subunits associated in a "hand-to-hand" mode by complexation via two adjacent bipyridine units to two copper(I) cations, and each group of two residual, adjacent, bipyridine arms is complexed to one copper(I) centre. Mass spectrometry, UV spectroscopy and preliminary 1H-NMR analysis are in preliminary accordance with a monocalixarenic right/left handed M2L structure. Nevertheless, some particularities of the NMR spectrum related to Ar-CH2-Ar and O-CH2bpy resonance signals, the possible generation of the M2L species during the mass spectrometry experiment and the lack of sensitivity of the UV-visible titration caused us to proceed to deeper investigations, looking for other associations, notably the M4L2 "hand-to-hand" systems. This involved 1D and 2D-NMR spectroscopies, among them 1H–15N HMBC, for the reconstruction of the molecule, but also the measurement of self-diffusion coefficients by NMR and electrochemistry. The 2D-NMR analysis and NMR self-diffusion evaluation were in accordance with the M2L structure, but the electrochemical self-diffusion experiment indicated a M4L2 structure. [ABSTRACT FROM AUTHOR]

Laser-ablation spark-induced breakdown spectroscopy (LA-SIBS) based on a fiber laser operated at 30 kHz pulse repetition rate was first developed to realize sensitive elemental analysis of minor elements in copper alloys. The characteristics of the spark discharge operated at 30 kHz repetition rate and the effects of discharge voltage as well as the capacitance of the energy storage capacitor on the signal intensities of different atomic lines and their signal-to-background ratios were studied. The calibration curves of lead, iron and aluminum in copper alloys have been generated using a compact fiber spectrometer to analyze the spectra. Selecting Pb I 368.35 nm, Fe I 358.12 nm and Al I 396.15 nm analytical lines, the detection limits of lead, iron and aluminum in copper alloys were determined to be 1309, 1022 and 106 ppm when the sample was only ablated by a fiber laser with 0.6 mJ pulse energy. With the assistance of the spark discharge, these detection limits have been improved to be 240, 113 and 30 ppm, demonstrating a 3–9 fold enhancement of the detection limit under current experimental conditions. This work demonstrates that the spark discharge can be used to improve the analytical sensitivity of a portable laser-induced breakdown spectroscopic system consisting of a fiber laser and a fiber spectrometer. The portable LA-SIBS system based on a fiber laser and fiber spectrometer will be helpful to realize more sensitive elemental analysis for different solid samples than a portable LIBS system that consists of the same fiber laser and the same fiber spectrometer. [ABSTRACT FROM AUTHOR]

The reaction of copper(ii) acetate monohydrate with p-hydroxycinnamic acid (HpOHcinn) and different pyridine derivatives (4-tert-butylpyridine, 4-tBupy; 4-acetylpyridine, 4-Acpy; 3-phenylpyridine, 3-Phpy; 4-phenylpyridine, 4-Phpy) was essayed in methanol solvent at room temperature. The crystal structures of the resulting compounds were elucidated. Their analysis shows that the choice of pyridine ligands determines different coordination modes of the pOHcinn ligand and the Cu(ii) coordination, nuclearity and geometry. The pOHcinn acts as a monodentate carboxylate ligand in combination with 4-tBupy or 4-Phpy, yielding monomers and dimers, associated by hydrogen bonds into supramolecular networks in which the phenol group plays a key role. Conversely, in combination with 4-Acpy or 3-Phpy, the phenol group coordinates directly to the Cu(ii), acting as a ditopic ligand and yielding 2D coordination polymers. The compound containing 3-Phpy shows interesting MeOH–H2O reversible exchange behavior. Not only has the pyridine auxiliary ligand had a tremendous effect on the coordination mode of pOHcinn, but also its reactivity is influenced. Particularly, in the case of the compound containing 4-Phpy, it undergoes a photoinduced process, in which the phenol group deprotonates and coordinates to Cu(ii) as a phenoxy ligand. This yields a coordination polymer in which two different dimers alternate, bridged by the resulting pOcinn ligand. The magneto-structural correlation of this compound is also discussed. [ABSTRACT FROM AUTHOR]

An easily synthesized fluorescent probe for detecting copper in aqueous samples, with a short response time and at neutral pH, has been investigated. Through the chelation of Cu2+ ions or by binding to CuO nanoparticles, the fluorescence emission of the 2-(aminomethyl)aniline derivative H2L is quenched by over 50%. Spectroscopic determination of the association constants of H2L with some metal ions showed that the ligand has a higher affinity toward Cu2+ than toward other d-block metal ions. The comparative bonding ability of the aniline-based fluorescent probe in d-block metal complexes was studied in solution by a combination of UV-Vis, 1H NMR and mass spectrometry analyses. Besides these, the bonding behavior has been investigated in the solid state by X-ray diffraction, FT-IR spectroscopy and elemental analysis. The crystal structures of Pd2(L)2 and Co(L)(HL)(H2O) were elucidated. [ABSTRACT FROM AUTHOR]

Isotope Dilution Inductively Coupled Plasma Mass Spectrometry (ID-ICP-MS) has been applied to the accurate determination of elements in human serum. However, in the determination of Cu, because of high Na concentration (approximate 3500 μg g−1) and other potential interfering elements (such as Ca, Mg, P and S), it is often a considerably difficult matter to accurately determine the 63Cu/65Cu ratio in the isotope dilution quadrupole ICP-MS (ID-Q-ICP-MS) procedure. In this study, a method for the quantitative correction of matrix effects is presented in the analysis of Cu in a human serum sample by ID-Q-ICP-MS. The potential matrix effects induced by non-spectral and spectral interference are fully investigated, and the polyatomic interference caused by high concentration of Na is proved to be the most important source of matrix effects in Cu determination. On this basis, a series of simulated Na matrix solutions with different 63Cu/65Cu ratios (from 0.1158 to 2.2440) are prepared to confirm the matrix correction factor, which is used for matrix correction after subsequent standard-sample bracketing (SSB) mass bias correction during ID-ICP-MS analysis. Moreover, this methodology is validated by using high resolution (HR) ICP-MS, and the consistent results prove the validity of this quantitative correction strategy. This idea will help to open the way to certain applications involving isotope ratio measurements, which previously have been beyond the reach of quadrupole ICP-MS instruments. [ABSTRACT FROM AUTHOR]

The article discusses various topics including the preparation of copper nanoparticles, use of antibiotics for treatment of bacterial infection, and provides details of the editorial board members of the journal.

Polyaromatic amphiphilic probes have been developed, that can be involved in chromogenic detection of Cu + ions in anionic micelles. A rapid change in solution color from yellow to orange was observed in the presence of Cu + ions. The detection limit was found at the nanomolar range. To the best of our knowledge, this is the first report of the visible detection of Cu + ions in aqueous medium using anionic micelles as a stabilizing agent. Interestingly, the compound can also detect Cu + ions, generated in situ from physiological redox processes. The mechanistic investigation suggests that the probe molecule forms a diamagnetic tetrahedral complex with the Cu + ion, coordinating through a pyridyl ketone unit. In addition, we have also followed the interaction with Cu + on a bilayer surface made of anionic phospholipids. Further, a Cu 2+ -probe ensemble is used to assay the reducing ability of different biogenic thiols depending upon the p K a of their sulfhydryl (-SH) group. This allows us to determine the amount of reducing thiols present in human urine samples. Considering the high sensitivity of the present system, we screened water samples collected from different natural sources for Cu + ions. Nearly 100% recovery values with considerably small relative standard deviations (<5%) indicate that the present system is indeed suitable for real-life sample analysis. Finally, low-cost, reusable, chemically-modified paper strips have been developed for rapid, on-location detection of Cu + ions.

Extensive investigations have been carried out in recent years on the effects of the presence of small amounts of molecular gases in analytical glow discharges (GDs) using argon as the plasma gas. Complementary studies using neon have shown that, when hydrogen is added to a neon discharge with a copper sample, the intensities of lines from most of the upper energy levels in the Cu II 3d9(2D)4p sub-configuration decrease. However, the 224.700 nm spectral line and other lines from the same upper level (3Po2) increase in intensity and this effect cannot be produced by the excitation processes normally considered. We show that asymmetric charge transfer (ACT) excitation by hydrogen molecules (H2-ACT) is the most likely explanation, the first time this process has been reported for any element in analytical GDs. We also explain why a similar effect is not observed with added nitrogen, although the ionization energies of hydrogen and nitrogen molecules are very similar. [ABSTRACT FROM AUTHOR]

Glow discharge mass spectrometry (GDMS) with its high resolution, low limit of determination and wide linear dynamic range is a powerful technique for direct analysis of high purity solid metals. Similar to the drawback of other direct solid sampling methods, a drawback of this technique is the lack of appropriate pure certified reference materials to calibrate the instrument, so that it is often used for semi-quantity analysis. A new calibration procedure using synthetic calibration samples by the doping-melting method was developed to obtain more accurate and traceable analytical results. The calibration samples were prepared from high purity copper powder doped with standard solutions of graduated and defined concentration. And then a part of them was melted into bulks and another was pressed to tablets. The homogeneity of both types of samples was measured by GDMS and for the doped tablets, relative deviations of the IBRs of both sides for 45 elements were mostly less than 10%. For the doped bulks, some problems such as the segregation effect and analyte losses happened for most elements; so satisfactory homogeneity was obtained for only 9 elements, for which nearly all relative deviations of the IBRs of both sides were less than 5%. Relative sensitivity factors of 9 and 45 elements in the copper matrix were obtained by calibration of GDMS with doped bulks and doped tablets, respectively. The RSF values obtained by calibration with doped tablets were compared with values derived from standard RSFs and the large differences demonstrated that matrix-adapted calibration was necessary when the impurities were measured accurately by using the instrument, especially for the rare earth elements. Then the 9 RSFs determined using tablets and bulks were compared and the results showed that relative deviations of them in most cases were less than 10%. The correlation coefficients of the calibration curves obtained by using the doping-melting method were better than those obtained using the doping-pressed method and the uncertainties of RSFs were smaller. Several copper CRMs were measured to validate the calibration procedures. The results revealed that the measured values using the two types of calibration samples were in agreement with the certified values. The results revealed that the calibration results of Fe and Ni coming from calibration samples prepared by using the two types of methods were in agreement with the certified values. [ABSTRACT FROM AUTHOR]

In this study, an optical analytical naked-eye sensor based on thiourea–polyvinyl alcohol (PVA) microspheres was designed for the selective recognition of heavy metals in aqueous solutions. The colorimetric sensor was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy to confirm the linkage of the chromophore with the surface of PVA microspheres. In the sensing system, notable changes in absorbance intensity of the colorimetric sensor for Hg2+ and Cu2+ were observed at pH 3 and 4, respectively. The sensor could selectively recognize heavy metals, as shown by the change in color from faint yellow to orange for Hg2+ and from faint yellow to dark green for Cu2+. The sensor provided consistent data reliability, with a detection limit of 0.209 and 0.320 μM by UV-vis spectrometry for Hg2+ and Cu2+, respectively. The prepared colorimetric sensor can be used to monitor Hg2+ and Cu2+ with satisfactory results because of its selectivity, reversibility, sensitivity, and signal stability. [ABSTRACT FROM AUTHOR]

In this study, an optical analytical naked-eye sensor based on thiourea–polyvinyl alcohol (PVA) microspheres was designed for the selective recognition of heavy metals in aqueous solutions. The colorimetric sensor was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy to confirm the linkage of the chromophore with the surface of PVA microspheres. In the sensing system, notable changes in absorbance intensity of the colorimetric sensor for Hg2+ and Cu2+ were observed at pH 3 and 4, respectively. The sensor could selectively recognize heavy metals, as shown by the change in color from faint yellow to orange for Hg2+ and from faint yellow to dark green for Cu2+. The sensor provided consistent data reliability, with a detection limit of 0.209 and 0.320 μM by UV-vis spectrometry for Hg2+ and Cu2+, respectively. The prepared colorimetric sensor can be used to monitor Hg2+ and Cu2+ with satisfactory results because of its selectivity, reversibility, sensitivity, and signal stability. [ABSTRACT FROM AUTHOR]

Four novel luminescent materials, namely, [Ag3(3,2′,3′-dpob)(bpy)]n (1·Ag), [Ag(3,3′,4′-H2dpob)(bpy)]n (2·Ag), [Ag3(3,2′,3′-Hdpob)(3,2′,3′-H2dpob)(bib)3·2H2O]n (3·Ag), and [Cu(3,2′,3′-Hdpob)(bib)·2H2O]n (4·Cu) [3,2′,3′-H3dpob = 3-(2′,3′-dicarboxylphenoxy)benzonic acid; 3,3′,4′-H3dpob = 3-(3′,4′-dicarboxylphenoxy)benzonic acid; bpy = 4,4′-bipyridine; bib = 1,4-bis(1-imidazoly)benzene] have been hydrothermally synthesized by mixed ligands and characterized using single crystal X-ray diffraction, infrared (IR), elemental analysis and thermogravimetric analysis (TGA). The crystal structures of four compounds indicate that the hydrogen bonding (O–H…O, C–H…O and C–H…π) and π…π stacking interactions play critical roles in the formation of the extended supramolecular array. 1·Ag displays a rare 3D compact structure with a 1D right-handed helical chain [–Ag1–CO2–Ag3–CO2–Ag1–]. 2·Ag and 3·Ag exhibit a 3D supramolecular architecture linked by intermolecular hydrogen bonds based on a 1D double-chain and 1D triple-chain, respectively. 4·Cu shows a 1D + 1D → 2D sheet, which is propagated to form an extended 3D structure with pcu (primitive cubic) topology viaπ…π stacking. The four compounds display remarkable narrow band emission with smaller full width at half-maximum (FWHM) (77 K, 97.91, 92.27, 72.98 and 77.96 nm; 298 K, 169.41, 241.98, 293.66 and 148.50 nm) in the solid state. The combination of such narrow FWHM and the red-shift from 298 K to 77 K endow them with a prominent thermochromic effect. It is worth noting that 2·Ag and 3·Ag display good aggregation-induced emission (AIE) properties. Both of them show very weak luminescence in dimethyl sulfoxide (DMSO, good solvent) while their intensities increased enormously with the addition of water (H2O, poor solvent) due to aggregation. In addition, adsorption spectra reveal their semiconductive nature (2.35 eV for 1·Ag and 2.91 eV for 3·Ag) and the role of Ag…Ag interactions in controlling the performance of semiconductive properties is highlighted. [ABSTRACT FROM AUTHOR]

In supplementary work to the one published earlier, experiments with SF6, NF3, CF4 and H2 as new modifier gases for the matrix studied were performed. Our investigations were continued to improve the described analytical method and to achieve additional insights into the mechanism of analyte release. Our new survey is split in two parts. At first fluorinating modifiers were used to investigate the behaviour of a variety of trace elements (Ag, Al, As, Au, Bi, Cd, Co, Cr, Fe, Mg, Mn, Ni, P, Pb, Sb, Se, Si, Sn, Te, Ti, Zn and Zr). Most of them (exceptions Au, Se, and Te) could be effectively released from the copper matrix by thermo-halogenation reactions and by partial sub-sample evaporation. Using SF6 and NF3 as modifier gases, low limits of quantification (LOQs) were achieved for the 19 well released trace elements (typical ≤0.1 mg kg−1). Most elements (exceptions Ag, Mg, and Ni) could be calibrated by using aqueous calibration solutions without any sample pretreatment. For the trace determination of Se, Te, and Au, a further analytical method of ETV-ICP OES is described in the second part based on thermo-hydrogenation reactions by using a hydrogen/argon mixture as a modifier gas. The determination of Se and Te with very high analytical performance (LOQ ＜ 0.1 mg kg−1) can either be carried out in a second analytical step succeeding the halogenation procedure, or the sub-sample is directly treated with H2 without previous halogenation procedure whereby the sub-sample can either be partially or totally evaporated. In this case some other analytes (Ag, Au, As, Bi, Cd, Fe, Mg, Ni, Pb, Sb, Sn, and Zn) can additionally be quantified simultaneously with Se and Te. [ABSTRACT FROM AUTHOR]

The encapsulation of a fluoride ion in a trigonal prismatic CuII6-pyrazolato cage results in a small expansion of the Cu6-host. The structural, electronic and magnetic features of the Cu6-complex, containing an endohedral fluoride in the rare μ6-F coordination mode, are compared with those of the parent complex with a vacant Cu6-cage. [ABSTRACT FROM AUTHOR]

Two copper hydroxychlorides, A3Cu3(OH)Cl8 (A = Cs, Rb), were synthesized by a hydrothermal method, which crystallize in the space group P21/c. All copper atoms are coordinated with three Cl atoms and one OH group forming quite distorted squares of CuCl3(OH), which further share one edge and one corner to form an isolated triangle unit of [Cu3(OH)Cl8]3− with μ2-Cl and μ3-OH cores. Interestingly, the two isostructural compounds exhibit antiferromagnetic ordering at low temperature and the dominant exchange coupling in the isolated triangle is found to be of ferromagnetic type, ruling out geometrical frustration effects. The origin of such a ferromagnetic interaction is suggested to arise likely from the folded [Cu(2)Cu(3)(OH)Cl5]2− dimers with a Cu(2)–Cl(5)–Cu(3) route. [ABSTRACT FROM AUTHOR]

We report the synthesis, characterization, crystal structures, nonlinear-optical (NLO) properties, and density functional theory (DFT) calculations of nickel(ii) and copper(ii) complex based ONO tridentate Schiff base ligands: two mononuclear compounds, [Ni(An-ONO)(NC5H5)] (5) and [Cu(An-ONO)(4-NC5H4C(CH3)3)] (6), and two heterobimetallic species, [M(Fc-ONO)(NC5H5)] (M = Ni, 7; Cu, 8), where An-ONOH2 (3) and Fc-ONOH2 (4) are the 1 : 1 condensation products of 2-aminophenol and p-anisoylacetone and ferrocenoylacetone, respectively. These compounds were characterised by microanalysis, FT-IR and X-ray crystallography in the solid state and in solution by UV-vis and 1H and 13C NMR spectroscopy. The crystal structures of 3–5, 7 and 8 have been determined and show for Schiff base complexes 5, 7 and 8 a four-coordinated square-planar environment for nickel and copper ions. The electrochemical behavior of all derivatives 3–8 was investigated by cyclic voltammetry in dichloromethane, and discussed on the basis of DFT-computed electronic structures of the neutral and oxidized forms of the compounds. The second-order NLO responses of 3–8 have been determined by harmonic light scattering measurements using a 10−2 M solution of dichloromethane and working with a 1.91 μm incident wavelength, giving rather high β1.91 values of 350 and 290 × 10−30 esu for the mononuclear species 5 and 6, respectively. The assignment and the nature of the electronic transitions observed in the UV-vis spectra were analyzed using time-dependent (TD) DFT calculations. They are dominated by LMCT, MLCT and π–π* transitions. [ABSTRACT FROM AUTHOR]

A switchable solvent-based liquid phase microextraction (SS-LPME) procedure has been established for the preconcentration of copper prior to its determination by microsampling flame atomic absorption spectrometry (FAAS). Triethylamine (TEA) was adopted for the study as a green and cheap switchable solvent. The Cu(ii)-1-(2-pyridylazo)-2-naphthol (PAN) complex was extracted into the TEA phase by converting the protonated carbonate (P-TEA-C) to TEA. The experimental conditions have been comprehensively studied and optimized. The limit of detection (LOD) and repeatability (RSD%) of the method were 1.80 μg L−1 and 3.8%, respectively, and its accuracy was assessed against certified reference materials (TMDA-64.2 fortified water, TMDA-53.3 fortified water, TMDA-51.3 fortified water, 1573a tomato leaves, INCT-OBTL-5 oriental basma tobacco leaves and NCS ZC 8100 2b human hair), and by addition-recovery tests. The SS-LPME-FAAS method was also applied for the determination of trace amounts of copper in water, food and hair samples. [ABSTRACT FROM AUTHOR]

In this work the determination of Cd, Cu, Cr, Fe and Sb as organic and inorganic additives in in-house plastic materials (ABS, LDPE) using electrothermal vaporization combined with inductively coupled plasma optical emission spectroscopy is described. The influence of CCl2F2 as gaseous halogenation modifier was investigated. Especially for the carbide forming elements the sensitivity was improved and the memory effects were significantly reduced. Calibration was performed by external calibration and standard addition with aqueous standard solutions added directly into the sample boats. Absolute limits of detection (3s-criterion) range between 0.1 ng (Cd) and 9 ng (Fe) which corresponds to relative values of 0.1 mg kg−1 and 1.6 mg kg−1, respectively, taking 5 mg as typical sample mass. The detection limits are sufficient to monitor the element contents of plastic materials according to European directives such as European directive on the safety of toys. The developed ETV-ICP-OES method allows a fast analysis with a high sample throughput (3 minutes per analysis), low sample consumption and good trueness and precision for the analyzed elements. Sample preparation is reduced to ashing the samples in a muffle furnace. Furthermore, measurements are possible regardless of the chemical form in the additives. For verification the results obtained with the developed method were compared with measurement results of independent methods ICP-MS/OES after digestion. In addition Cd, Cr and Pb were determined in a solid plastic reference material BAM-H010 to confirm the applicability and accuracy of the method. [ABSTRACT FROM AUTHOR]

We have designed and developed stable and biocompatible copper analogues of a Prussian blue (PB) nanoparticle based drug delivery system containing doxorubicin that show selective quenching of fluorescence of doxorubicin compared to PB analogues with other metals and inhibition of cancer cell proliferation, suggesting future potential multifunctional applications in biomedical sciences. [ABSTRACT FROM AUTHOR]

A chemosensor (NBD-H) based on an amino acid with 7-nitro-2,1,3-benzoxadiazole was used for selective detection of HgII and CuII among 15 metal ions in aqueous solutions by a colorimetric change. NBD-H sensitively differentiated HgII and CuII in aqueous solutions by a color change; a pink color for HgII and an orange color for CuII. NBD-H showed nanomolar detection limits for HgII (176 nM, R2 = 0.996) and CuII (163 nM, R2 = 0.996). The detection limit for CuII was much lower than the maximum allowable level of CuII in drinking water recommended by the U.S. EPA. The binding mode study showed that deprotonation of the NH group of NBD-H played a critical role in the binding and sensing of metal ions. NBD-H immobilized on PEG-PS resin maintained the potent binding affinity and sensing ability for the metal ions. The resin with NBD-H was recyclable for the detection of metal ions in 100% aqueous solutions. [ABSTRACT FROM AUTHOR]

Members of the cytochrome c oxidase family exhibit nitrite reductase activity. In this work, we have characterized a ferrous heme a3-nitro species in ba3-oxidase by resonance Raman spectroscopy. This provides the first evidence for the structure of a nitrite-bound species in the binuclear heme/copper center of cytochrome c oxidases. [ABSTRACT FROM AUTHOR]

Here we report synthesis and characterization of early transition-metal(TM)-substituted decaniobates as a continuation of our previous report of tetramethylammonium (TMA) salt of FeNb9 and NiNb9: TMA6[H2CrIIINb9O28]·14H2O (1, CrNb9), TMA8[MnIIINb9O28]·29H2O (2, MnNb9) and TMA7 [H2CoIINb9O28]· 25H2O (3, CoNb9). Among the TM-substituted decaniobates, CoNb9 or NiNb9 exhibit a higher photocatalytic H2 evolution activity in methanol-water mixtures than others. [ABSTRACT FROM AUTHOR]

For realizing selective adsorption of targeted molecules, a flexible metal-organic framework (MOF) was modified with monodentate secondary ligands. Although the modified MOF retains CO2 adsorptivities with a vertical adsorption uptake, the material also shows gate adsorptivities of a specific gas molecule that the pristine MOF does not adsorb. [ABSTRACT FROM AUTHOR]

Since there is a significant difference in the isotopic composition of Cu and Fe in whole blood between men and women, it was hypothesized that menstruation and the associated Cu and Fe loss affect the isotopic composition of these metabolically relevant transition metals. To assess this hypothesis, whole blood from two groups of non-menstruating women was analyzed for its Cu, Fe and Zn isotopic composition using multi-collector ICP-mass spectrometry (MC-ICP-MS) and the results were compared to the values for a male and a female reference population. The first group of non-menstruating women consisted of women in their menopause, while the second group consisted of women that were not menstruating because of an intra-uterine device (IUD). Also the effect of age on the isotopic composition of Cu, Fe and Zn in whole blood was investigated. The Cu and Fe isotopic composition of whole blood indeed seems to be influenced by menstruation. Non-menstruating women show an isotopic signature indistinguishable from that of the male reference population. The results for both groups of non-menstruating women do not differ significantly from one another and there does not seem to be an "age effect" for these two elements. Also for the isotopic composition of Zn in whole blood, no age effect could be demonstrated. No influence of menstruation was found either. However, a significant difference in the Zn isotopic composition was found between women in their menopause and women with an IUD. Possibly, this can be explained by a hormonal effect on the isotopic signature of Zn. [ABSTRACT FROM AUTHOR]

The large surface areas in porous organic matter (OM) and on the surface of altered minerals control the sequestration of metal(loid)s in contaminated soils and sediments. This study explores the sequestration of Cu by OM in surficial forest soil in close proximity to the Horne smelter, Rouyn-Noranda, Quebec, Canada. The organic-rich soils have elevated concentrations of Cu (Cu = 〈0.75〉 wt%) but lack associations between organic matter (OM) and Cu-sulfides, commonly observed in organic-rich Cu-contaminated soils. This provides a unique opportunity to study the sequestration of Cu by OM in a sulfur-depleted environment using a combination of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atom probe tomography (APT). In two examined OM particles, Cu is predominantly sequestered as (I) nano- to micrometer-size Cu-bearing spinels, (II) as cuprite (Cu 2 O) nanoparticles or (III) finely dispersed Cu in association with clusters of magnetite (Fe 3 O 4 ) nanoparticles embedded in amorphous silica-rich pockets and (IV) in the OM matrix. The occurrence of euhedral crystals and nanoparticles in the single-digit range within the OM matrix indicate that the majority of the nanoparticles formed in situ within the OM particles. A model is developed which proposes that the sequestration of Cu in OM is promoted by (I) the partial mineralization of the OM matrix by amorphous silica; (II) the nucleation of magnetite nanoparticles on highly reactive silanol groups; (III) the diffusion of Cu within mineralized and altered areas of the OM; (IV) the availability of Cu-bearing species, which in turn is controlled by the hydrodynamic properties of the pore channels; (V) the formation of precursors and nucleation of Cu-bearing nanoparticles. This study shows that the combination of SEM, TEM and APT provides new insights into the sequestration of metal contaminants by OM at various scales ranging from the single-digit nano- to micrometer scale.

Exposure to lead, a toxic heavy metal, in drinking water is a worldwide problem. Lead leaching from lead service lines, the main contamination source, and other plumbing materials is controlled by the plumbosolvency of water. Square wave anodic stripping voltammetry (SWASV) has been greatly explored as a rapid and portable technique for the detection of trace Pb 2+ ions in drinking water. However, the impact of water quality parameters (WQP) on the SWASV technique is not well understood. Herein, SWASV was employed to detect 10 μg L -1 Pb 2+ and determine trends in the stripping peak changes in simulated water samples while individually varying the pH, conductivity, alkalinity, free chlorine, temperature, and copper levels. The pH and conductivity were controlled using the buffer 3-( N -morpholino)propanesulfonic acid (MOPS), and NaNO 3 , respectively and kept at pH = 7.0 and conductivity = 500 μS cm -1 when exploring other WQPs. The working electrode, a gold-nanoparticle-modified carbon nanotube fiber cross-section (AuNP-CNT f -CS) electrode provided sufficiently sharp and prominent peaks for 10 μg L -1 Pb 2+ detection as well as good reproducibility, with a relative error of 5.9% in simulated water. We found that conductivity, and temperature had a proportional relationship to the peak height, and pH, alkalinity, free chlorine, and copper had an inverse relationship. In addition, increasing the copper concentration caused broadening and shifting of the Pb 2+ stripping peak. At extremely low conductivities (<100 μS cm -1 ), the voltammograms became difficult to interpret owing to the formation of inverted and distorted peaks. These trends were then also observed within a local drinking water sample in order to validate the results.

Two new Keggin-based hybrids with polynuclear Cu(i) clusters, formulated as [Cu4(HL)4(SiW12O40)]·6H2O (1) and [Cu6.5(HL)2(L)4(H2O)(H1.5SiW12O40)]·3H2O (2) (HL = 5-(4-imidazol-1-ylphenyl)-2H-tetrazole), have been hydrothermally synthesized and characterized by routine techniques. In 1, Keggin polyanions [SiW12O40]4− (SiW12) link adjacent [Cu4(HL)4]n chains to generate a 2D network. In 2, a cationic (2,3,11)-connected 3D framework, {Cu6.5(HL)2(L)4(H2O)}2.5+, is induced by SiW12 as the template. The differences in the structures of compounds 1 and 2 indicate that pH and the acid radical ions in the initial reaction system play a key role in determining the final structures. Interestingly, the ligand HL in 1 only adopts a μ1,2,3 bridging mode, while in 2, the ligand is in HL/L states and exhibits four different bridging modes: μ1,2,3,4,5, μ1,2,3,5, μ1,2,4,5, and μ1,2,4. The luminescent properties of compounds 1 and 2 have also been investigated. The results show that solvent-dependent luminescence properties can be found in 1. In addition, electrochemistry properties of 1 and 2 have also been studied. [ABSTRACT FROM AUTHOR]

The synthesis, structures and magnetic characterisation of a family of discrete planar pentanuclear Cu(ii) 12-MC-4 metallacrowns of formulae [Cu5(L1)4(MeOH)4](ClO4)2 (1), [Cu5(L1)4(py)2](ClO4)2·py (2), [Cu5(L1)4(py)6](ClO4)2 (3) and [Cu5(L2)4(MeOH)4](ClO4)2·H2O (7) (where L1H2 = 2-(dimethylamino)phenylhydroxamic acid and L2H2 = 2-(amino)phenylhydroxamic acid) are reported. UV-vis and Electrospray MS studies indicate solution stability with respect to their {Cu5(L)4}2+ cores. Magnetic susceptibility measurements confirm strong antiferromagnetic exchange between the Cu(ii) ions resulting in isolated S = 1/2 ground spin states. The introduction of ditopic co-ligands such as 4,4′-bipyridine (4,4′-bipy), pyrazine (pz) and 4,4′-azopyridine (4,4′-azp) results in their coordination at a number of axial Cu(ii) sites within the {Cu5} metallacrown nodes to afford the extended networks {[Cu5(L1)4(4,4′-bipy)3](ClO4)2·(H2O)}n (4), {[Cu5(L1)4(4,4′-azp)2(MeOH)2](ClO4)2}n (5) and {[Cu5(L2)4(pz)2(MeOH)3](ClO4)2·MeOH}n (6). [ABSTRACT FROM AUTHOR]

Ionic liquids of methyltrioctylammonium chloride modified magnetic nanoparticles were prepared, and a new method of magnetic solid phase extraction combined with inductively coupled plasma-optical emission spectrometry was established for the determination of Cu, Zn, and Cd in human hair and urine samples. The effect of pH on the extraction of Cu, Zn, and Cd was investigated. The results show that the ionic liquid played a key role in the extraction of target analytes. The magnetic nanoparticles served as the carriers of the ionic liquid and the base of the phase separation. Several parameters affecting the extraction and desorption of the target analytes were investigated including the sample volume, extraction time, eluent concentration and volume, desorption time, sedimentation time, amount of the ionic liquid and Fe3O4@Si–OH, and the optimized conditions were established. Under the optimized conditions, the detection limits of Cu, Zn, and Cd were 0.54, 0.56, and 0.33 μg L−1, respectively, and the relative standard deviations (n = 7) were 4.9% (c = 2 μg L−1), 3.7% (c = 2 μg L−1), and 5.1% (c = 1 μg L−1), respectively. To validate the accuracy of the proposed method, it was applied to analyze certified reference materials of GBW07601 human hair and GBW09103 human urine. The determined values agree with the certified values. The developed method was also employed to analyze human hair and urine, and the recoveries for the spiked samples were in the range of 89.1% to 120%. The developed method was simple, highly sensitive, solvent-free, chelate-free, and could be considered as a green analytical technique. [ABSTRACT FROM AUTHOR]

In this study, a highly selective and sensitive fluorescence assay has been proposed for the determination of copper(ii) and cobalt(ii) ions in environmental water and toner samples. In the presence of hydrogen peroxide, copper(ii) reacted with a new fluorescence reagent Amplex® UltraRed (AUR), forming a fluorescence product only at pH 7.0, while the fluorescence product of cobalt(ii) with AUR formed only at pH 9.0. The fluorescence signal obtained was linear with respect to the copper(ii) concentration over the range of 1.6–12.0 μM (R2 = 0.988) and was linear with respect to the cobalt(ii) concentration over the range of 45.0 nM to 1.0 μM (R2 = 0.992). The limits of detection (at a signal-to-noise ratio of 3) for copper(ii) and cobalt(ii) were 0.17 μM and 14.0 nM, respectively. Our present approach is simpler, faster, and more cost-effective than other techniques for the detection of copper(ii) and cobalt(ii) ions in environmental water samples and that of copper(ii) ions in toner samples. [ABSTRACT FROM AUTHOR]

This study shows that Cu occurs predominantly as Cu-sulfides and Cu-bearing phosphates and -carbonates in organic matter (OM) colloids within smelter-impacted soils in which they are often associated with other inorganic components. Major emitters of Cu are smelters and coal-power plants, which cause severe damage to the health of soils and aquatic systems as elevated Cu concentrations are toxic for terrestrial and aquatic organisms. Toxic effects and the long-term environmental fate of Cu depend among many other factors on its speciation in soil and water bodies. This study explores the role of OM colloids (defined as particles with diameters in the range of 100 to 1000 nm and with a larger proportion of organic than inorganic material) in the sequestration of Cu in contaminated soils around the Horne smelter, Rouyn Noranda, Quebec, Canada, focusing on a thin soil overlying bedrock (bedrock soil) and forest soil. The sequestration and mobilization of Cu by OM colloids are studied using a combination of column leaching experiments, ultra-centrifugation and transmission electron microscopy (TEM). TEM analysis indicates that Cu occurs as nano-sized CuS x phases in OM colloids of the bedrock soil, and as Cu-bearing Ca-Mg-phosphates and Ca-carbonates in OM colloids of the forest soil. The nano-sized CuS x phases occur along the rim of OM colloids or are attached to silica inclusions located within OM colloids, suggesting that their in situ formation is strongly controlled by the presence of polar groups within or on the surface of OM colloids. The proportion of Cu-bearing colloids in the soil leachates ranges from 20 to 40% of the total colloidal fraction, suggesting that OM colloids can play a significant role in the sequestration of Cu in surficial soil environments.

Isotopic fractionation during in-situ analysis of copper using laser ablation (LA) MC-ICP-MS has been investigated. Results show that particles <200 nm transported in the aerosol are isotopically lighter by up to 0.7‰ compared to the larger particles. The dependence of this isotopic fractionation on the ablation time, together with isotopic effects caused in the ICP during particle vaporisation, explains the variations of isotope ratios observed during LA-MC-ICP-MS. LA-MC-ICP-MS measurements of copper isotope ratios in metallic copper typically show large systematic within-run variations of up to several permil (‰) depending on the ablation time and, correspondingly, large offsets from solution data for the same sample when compared directly. Analysis of small particles generated by vapour condensation after the laser impact, and larger particles formed by ejection of liquid droplets from the crater, show that the laser impact results in isotopic fractionation of 65Cuﾭ슻 between different aerosol particle size fractions of up to 0.7‰. This fractionation cannot be overcome by removal of large particles from the aerosol that are not completely vaporised and ionised in the ICP source. However, separation of the large particles is shown to significantly reduce within-run fractionation, as well as improving the accuracy relative to solution data, and is therefore recommended for the analysis of copper metal. Temporal variations in the isotopic composition of particulate vapour condensate are explained by a crater effect that influences the residence time of large particles in the laser-generated plasma plume, leading to preferential vaporisation of the lighter isotopes. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of the new chiral ligand 2, based on a BINOL-tren (tren = tris(2-aminoethyl)amine) conjugate, in enantiomerically pure form, are reported. UV-Vis spectrophotometric and spectrofluorimetric studies at variable pH show that the incorporation of a phenolic functionality in close proximity to the polyamino fragment of the molecule causes a dramatic variation of the acid-base and coordination properties of the molecule; the major role of this functionality in determining the selectivity observed in the complexation of Cu2+, when compared with Zn2+ and Ni2+, at pH = 5 in aqueous MeOH, has been clarified, also by comparison with the spectroscopic and coordination properties of model compound 3, bearing protected OMe functionalities. The peculiar absorbance, emission and chiroptical properties of the binaphthyl fragment incorporated in compound 2 can be used for the selective detection of Cu2+ using three different and potentially orthogonal techniques, namely UV, CD and fluorescence spectroscopies. [ABSTRACT FROM AUTHOR]

In recent years, it has been found that Cu 2+ , Fe 3+ , and amino acids play an irreplaceable and subtle role in organisms and have attracted the considerable attention of many researchers. Therefore, it is vital to design visual indicators to reveal the relationships between metal ions and amino acids. However, there have been few reports on this vigorous subject. Fortunately, based on the different coordination effects between metal ions and boron groups, we have designed an accessible fluorescent probe (PSI-A). Borane was introduced as an ion-sensitive group to form a novel POSS-based fluorescent probe, which achieves fascinating performance, in situ dynamic multiple detection, excellent photostability, and enervative biological toxicity. PSI-A exhibited predominant selectivity and sensitivity to Cu 2+ /amino acids and Fe 3+ /amino acids sequence reactions in HepG2 cells and zebrafish. The fluorescence of PSI-A was quenched by Cu 2+ , which can be recovered by adding Asp, Ser, Arg, Ace or Trp. Additionally, the fluorescence of PSI-A quenched by Fe 3+ can be restored after adding Asp. PSI-A is available to monitor Cu 2+ /amino acids and Fe 3+ /amino acids sequence reactions and can be repeated for at least three consecutive cycles without a fatigued performance. Therefore, this multifunctional fluorescent probe may have prospective application potentials in the biological field.

Ratiometric fluorescent probes based on coordination polymers (CPs) have been widely applied in optical applications. Therefore, it is very important to develop a dual-emitting gel material based on coordination polymers for specific recognition of molecules. Cu-atda (H 2 atda = 3,3'-(4-amino-1,2,4-triazol-3,5-diyl) dibenzoic acid) is synthesized with a porous structure and a large number of amino sites exposed on the surface, which can be regarded as a carrier for fluorescent molecules and well disperse in the SA hydrogel network. A dual-emission Eu 3+ functionalized CP hydrogel bead (9A/Cu-atda@Eu3+/SA, 9A = 9-anthraldehyde and SA = sodium alginate) is successfully prepared, which presents ratiometric fluorescence detection of flumequine with a low detection limit (48 nM) and high selectivity. Furthermore, it also displays an excellent fluorescence quenching effect on nitrofuran antibiotics, exhibiting a dual functional performance. In addition, the fluorescence response mechanisms of flumequine and nitrofuran antibiotics are discussed in depth. As a portable material, visualization 9A/Cu-atda@Eu3+/SA beads provide an extensive and convenient application prospect for real-time monitoring of antibiotics in the water environment.

A synthetically facile and earth abundant Cu(i) metal-to-ligand charge transfer sensitizer was successfully incorporated into two distinct photochemical upconversion schemes, affording red-to-green and orange-to-blue wavelength conversions. [ABSTRACT FROM AUTHOR]

A series of functional IRMOF-3 frameworks with solid-state luminescence and tuneable light emission (from 490 to 608 nm) have been synthesized by per-functionalizing AIE-active Schiff-bases with zinc. These precursor AIE-active ligands endowed the functional frameworks with boosted fluorescence emission efficiencies (from 0.16% to 1.03%). IRMOF-3-h revealed a flower-like morphology attributed to the formation of J-aggregates, and could be used as a fluorescent probe for sensitive detection of copper(ii) (135 pM) and thiols (subnanomole).

The present article focuses on fluorescent probes based on Ru(ii)-polypyridyl fragments connected to different chelates, their significant roles in coordination chemistry and their applications in the selective recognition of biorelevant Cu2+ and Fe2+/Fe3+ ions. A critical analysis of the detection of metal ions by both "turn-on" and "turn-off" emission, properties, mechanism and applications of these sensors is presented. Emphasis has also been laid on the efficiency, selectivity and specificity of these sensors towards biologically important Cu2+ and Fe2+/Fe3+ ions.

Morphological, spectroscopic and scattering studies of the self-assembly and aggregation process of hybrids containing gold nanoparticles (AuNPs) and the amyloid peptides [RF]4 and P[RF]4 (where R = arginine; F = phenylalanine; P = proline) in aqueous solution were performed. Two methodologies were tested for the AuNP nucleation, using sodium borohydride (NaBH4) or epigallocatechin gallate (EGCG) as a reducing agent. This led to remarkable distinct modes of assembly, AuNP decorated fibrils with NaBH4 reduction or isolated AuNPs with EGCG reduction. For both methodologies, the presence of spherical AuNPs was observed by plasmonic resonance bands in absorption spectra at ∼520 nm. Zeta potential measurements confirmed stable systems, with a similar aggregation state. Circular dichroism spectra revealed an antiparallel β-sheet conformation of the peptides. The transmission electron microscopy (TEM) images showed the coexistence of nanometer fibers and globular nanoparticles with 20 nm size. The small-angle X-ray scattering (SAXS) results show that the NaBH4 systems presented large cylindrical structures, while with increasing P[RF]4 content, a decrease in radius was observed. However, the EGCG-AuNPs were characterized by spherical particles, with a radius of 10-20 nm. Also, the colorimetric efficiency of the hybrids in the capture of Cu2+ ions in solution was monitored. Raman spectroscopy data confirmed the conformation/structure of self-assembled samples. Moreover, there are indications for a surface-enhanced Raman spectroscopy (SERS) effect for Cu2+ sites. The set of results indicates that these systems could act as a promising sensitive metal concentration probes.

A highly sensitive AIE fluorescent chemosensor, N'-((4'-(6,6-dimethyl-4,5,6,7-tetrahydro-1H-5,7-methanoindazol-3-yl)-[1,1'-biphenyl]-4-yl)methylene)picolinohydrazide (PBPHS), for the detection of Hg2+ and Cu2+ ions in near 100% aqueous solution was developed based on the renewable β-pinene derivative nopinone. The probe PBPHS was designed and synthesized via a four reaction steps, including condensation, cyclization, Suzuki coupling reaction, and Schiff-base reaction. PBPHS could recognize Hg2+ and Cu2+ over other competitive metal ions via specific complexation ability towards them. The detection limits of PBPHS for Hg2+ and Cu2+ were 15 nM and 17 nM, respectively. The fluorescent probe PBPHS could also be utilized to detect S2- and Hg2+/Cu2+ reversibly for five cycle. Moreover, the different binding mechanisms of PBPHS with Hg2+ and Cu2+ were confirmed by HRMS analysis, 1H NMR titration, DFT calculation, and molecular logic gate. Furthermore, the probe PBPHS was applied for the analysis of real water and soil samples and living HeLa cells and zebrafish bioimaging.

In the past few years, the development of novel nanozymes with excellent performance has attracted increasing attention in biosensing. However, most of those nanozymes were found to possess peroxidase activity with the prerequisite of the presence of H2O2. In contrast, oxidase mimics can catalyze the oxidation of substrates without H2O2, delivering a higher signal-to-noise ratio than that of peroxidase mimics in practical applications. Herein, for the first time, two-dimensional (2D) nanosheets composed of iron phosphide embedded in a carbon matrix (FeP@C nanosheets) were found to demonstrate a robust oxidase-like property, different from those previously reported peroxidase mimics based on transition metal phosphides (TMPs). Based on this intriguing observation, the fluorescent substrate Amplex Red (AR) of peroxidase can be effectively oxidized by FeP@C nanosheets in the absence of H2O2. Benefiting from the oxidase-like enzymatic activity of the FeP@C nanosheets, a novel fluorescence sensing platform was developed for the detection of cysteine (Cys) and Cu2+. The outstanding performance of the 2D FeP@C nanosheets endows the proposed platform with superior sensitivity and selectivity compared to many previously reported approaches. Besides, the inherent features of simplicity, being label free, and low cost also allow this methodology to stand out among many other strategies, revealing its huge potential in practical analysis and detection applications.

Novel dual-ratio semiconducting polymer dots (Pdots) with trichromatic-emission in the red, green and blue primary-color regions, are designed as lysosome-targeting nanoprobes for the simultaneous detection and multicolor imaging of pH and Cu 2+ in HeLa cells and zebrafish without cross-interference.

Copper (Cu) is a vital metal element for humans and animals. Monitoring and evaluating the concentration level of Cu2+ in a biological body is an effective way to prevent a variety of diseases. In this work, phenyl doped graphitic carbon nitride (PDCN) nanosheets with strong green fluorescence exhibited a sensitive and selective detection for Cu2+ with a linear range from 0.1-2.0 μmol L-1. Furthermore, fluorescent imaging was applied to semiquantitatively detect Cu2+ in HeLa cells using PDCN nanosheets as the probe, which can avoid the interference of background autofluorescence. This work provided a low-cost and biologically friendly fluorescent probe to monitor the concentration level of Cu2+ in living cells.

A near-infrared ratiometric fluorescent probe CR-Ac based on a coumarin-benzopyrylium platform has been developed for selective detection of Cu 2+ . The cell imaging data revealed the capabilities of CR-Ac in monitoring the dynamic changes of subcellular Cu 2+ and the quantification of Cu 2+ levels in living cells.

The measurement of exchangeable Cu2+ levels in biological samples is gaining interest in the context of copper-related pathologies. Here, we report a Tb3+ luminescent turn-off sensor for Cu2+ based on the specific and suitable-affinity Xxx-Zzz-His (ATCUN) peptide motif, enabling Cu2+ detection in the presence of a biological fluorescent background.

Carbon dots (Cdots) play an important role in many biological and chemical applications. To prepare strongly fluorescent Cdots, the starting material should contain nitrogen in addition to carbon. Nucleobases are nitrogen rich with interesting metal binding properties. In this work, we prepared a series of Cdots with citrate as the carbon source, and ethylenediamine, adenosine, cytidine, thymidine or guanosine as the respective nitrogen sources. The resulting Cdots were all fluorescent with the ethylenediamine sample being the most strongly emissive. These Cdots were then tested for their metal sensitivity and all tested metal ions can quench their fluorescence. The fluorescence of the G-Cdots prepared with guanosine was quenched most efficiently by Cu2+, while the Cdots prepared with ethylenediamine were more sensitive to Hg2+. With the differential quenching by different metal ions, we prepared a sensor array to discriminate multiple metal ions, and quantified Cu2+ and Hg2+ at the same time. Our work has expanded the range of starting materials for preparing Cdots and showed that by tuning the precursor composition, Cdots with different optical and metal binding properties can be obtained, which is useful in constructing a sensing platform for a large number of metal ions.