MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 4
·1-8
·
IF 5.705
Shao Hong,Xu Dan,Ding Yadan,Hong Xia,Liu Yichun
The authors describe an “off-on” colorimetric and fluorometric assay for the determination of Cu(II). It is based on the use of upconversion nanoparticles (UCNPs) of type NaYF 4 :Yb(III),Er(III) that were functionalized with branched polyethylenimine (BPEI). A color change from colorless to blue occurs within 2 s after addition of Cu(II) to a solution of the modified UCNPs. The color change can be visually detected at Cu(II) concentrations down to 80 μM. The upconversion fluorescence of the modified UCNPs, measured at excitation wavelength of 980 nm, is reduced due to the predominant inner filter effect caused by the formation of the BPEI-Cu(II) complex. Normalized fluorescence intensity drops linearly in the 50 nM to 10 μM Cu(II) concentration range, and the fluorometric detection limit is 45 nM. Both the color and the fluorescence are recovered on addition of EDTA. Excellent selectivity over other metal ions and anions is achieved.
Upconversion nanoparticles of type NaYF4:Yb,Er were functionalized with branched polyethylenimine (UCNP/BPEI) and used in an “off-on” colorimetric and fluorometric assay for Cu(II). The upconversion fluorescence is selectively quenched on addition of Cu(II), and this is accompanied by a rapid colorless-to-blue color switch. The colorimetric changes and quenched fluorescence can be reversed by adding EDTA.
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MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 12
·4731-4740
·
IF 4.58
Lu Zhiwei,Zhang Junjun,Dai Wanlin,Lin Xueni,Ye Jiaping,Ye Jianshan
The authors report on a disposable sensor for the differential pulse anodic stripping voltammetric (DPASV) determination of the ions Zn(II), Pb(II) and Cu(II). Simultaneous detection is accomplished by using a screen-printed carbon electrode (SPCE) co-modified with an in-situ plated bismuth (Bi)) film and gold nanoparticles (AuNPs). The synergistic effect of the Bi film, and the large surface and good electrical conductivity of the AuNPs strongly assist in the co-deposition of the three ions. Four well-defined and fully separated anodic stripping peaks, at 540 mV for Zn(II), 50 mV for Pb(II), 140 mV for Bi(III) and 295 mV for Cu(II), all vs. Ag/AgCl, can be seen. The modified SPCE was characterized by scanning electron microscopy, X-ray diffraction, cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimized conditions, the sensor has a good response to these ions. The detection limits (at an S/N ratio of 3) are 50 ng·L −1 for Zn(II), 20 ng·L −1 for Pb(II), and 30 ng·L −1 for Cu(II). The method was applied to the determination of the 3 ions in spiked lake water samples.
Schematic of screen-printed carbon electrode (SPCE) co-modified with a bismuth film and gold nanoparticles for electrochemical simultaneous determination of Zn(II), Pb(II) and Cu(II) by differential pulse anodic stripping voltammetric (DPASV).
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INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2015
·Vol. 16
·期 7
·14464-14476
·
IF 2.862
Jing Wei,Lu Han,Jing Song,Mengfang Chen
The objectives of this study were to evaluate the binding behavior of Cu(II) and Eu(III) with water extractable organic matter (WEOM) in soil, and assess the competitive effect of the cations. Excitation-emission matrix (EEM) fluorescence spectrometry was used in combination with parallel factor analysis (PARAFAC) to obtain four WEOM components: fulvic-like, humic-like, microbial degraded humic-like, and protein-like substances. Fluorescence titration experiments were performed to obtain the binding parameters of PARAFAC-derived components with Cu(II) and Eu(III). The conditional complexation stability constants (logKM) of Cu(II) with the four components ranged from 5.49 to 5.94, and the Eu(III) logKMvalues were between 5.26 to 5.81. The component-specific binding parameters obtained from competitive binding experiments revealed that Cu(II) and Eu(III) competed for the same binding sites on the WEOM components. These results would help understand the molecular binding mechanisms of Cu(II) and Eu(III) with WEOM in soil environment.Keywords:water extractable organic matter;copper;europium;excitation-emission matrix;parallel factor analysis
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JOURNAL OF ORGANIC CHEMISTRY
·
2021
·
IF 4.354
Quan Zhu,Yunsong Luo,Yongyan Guo,Yushun Zhang,Yunhai Tao
A highly efficient and practical Pd(II)/Cu(OAc)2-catalyst system of Saegusa oxidation, which converts enol ethers to the corresponding enals with a number of diverse substrates at extremely low catalyst loadings (500 mol ppm) under ligand-free and aqueous conditions, is described. Its synthetic utility was demonstrated by large-scale applications of the catalyst system to important nature molecules. This work allows Saegusa oxidation to become a highly practical approach to preparing enals and also suggests new insight into the Pd(II)/Cu(II)-catalyst system for dehydrogenation of carbonyl compounds and decreasing Pd-catalyst loadings.
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JOURNAL OF COORDINATION CHEMISTRY
·
2021
·
IF 1.751
Yan Zhao,Xianying Duan,Guangguang Zhang,Meilin Wei
Two proton-conductive and luminescent organic-inorganic hybrid materials, {[Cu(II)(bhmbpy)(H2O)(Cl)0.5(CH3CN)]2[PW(VI)10W(V)2O39]}·4H2O(1) and {H2[Cu(I)(bhmbpy)2(Cl)Cu(I)(bhmbpy)2][PW12O40]}·7H2O (2) (where bhmbpy is bis(hydroxymethyl)-2,2′-bipyridine), were synthesized at room temperature. The two products were characterized by infrared spectroscopy, X-ray single-crystal diffraction, X-ray powder diffraction, elemental and thermogravimetric analyses. The proton conductivities and luminescence of 1 and 2 were studied by using alternating-current impedance spectroscopy and luminescence spectroscopy, respectively. X-ray diffraction analysis revealed that 1 includes a decorated polyanion chain {[Cu(II)(bhmbpy)(H2O)(Cl)0.5(CH3CN)]2[PW(VI)10W(V)2O39]}n and forms a three-dimensional network structure depending on short Cl…Cl contacts and hydrogen-bonding interactions. X-ray diffraction analysis revealed that 2 includes a butterfly-like bi-nuclear copper cluster unit with a Cl-bridge, [Cu(I)(bhmbpy)2(Cl)Cu(I)(bhmbpy)2]+, and forms a three-dimensional network structure depending on hydrogen-bonding interactions. [PW12O40]3– anions fill in the network based on hydrogen-bonding and electrostatic interactions. In them, the bhmbpy acts as a bidentate nitrogen donor ligand in the chelating fashion to coordinate with the Cu(II) center in 1 and the Cu(I) center in 2. The bhmbpy in 2 successfully constrains the Cu(I) within a rigid environment in a tetragonal-pyramidal geometry. The two compounds exhibit good proton conductivity (10−4 S·cm−1) at 100 °C in the relative humidity range 35–98%. Their luminescence behaviors in the solid state at room temperature have also been investigated. Upon excitation at 384 nm, 1 exhibits three emission peaks centered at 439, 507 and 566 nm. When excited at 364 nm, 2 displays three emission peaks centered at 443, 501 and 553 nm.
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EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
·
2018
·
IF 4.816
Yong-Yu Qi,Qian Gan,Ya-Xian Liu,Ya-Hong Xiong,Zong-Wan Mao,Xue-Yi Le
In the search for more effective anticancer drugs with less toxic side effects, dipeptides were introduced into the Cu(II) complex of 5-methyl-2-(2′-pyridyl)benzimidazole (HPBM). Analytical and spectroscopic techniques were employed to thoroughly characterize complexes [Cu(Gly-gly)(HPBM)(H 2 O)]ClO 4 ·0.5H 2 O ( 1 ) and [Cu(Gly- L -leu)(HPBM)(H 2 O)]ClO 4 ( 2 ) (where Gly-gly = Glycyl-glycine anion, Gly- L -leu = Glycyl- l -leucine anion). The solution stability studies performed by ultraviolet–visible (UV–Vis) spectroscopy confirmed the stability of the complexes in the buffer solutions. The DNA binding affinity was evaluated using multi-spectroscopy, viscosity measurement and molecular docking methods and further quantified by K b and K app values, revealing an intercalative mode. Moreover, gel electrophoresis analysis revealed that the complexes could damage CT DNA through a hydroxyl radical pathway in the presence of ascorbic acid . All the complexes displayed favorable antimicrobial and cytotoxic activities toward the tested microorganisms ( Bacillus subtilis , Staphylococcus aureus , Escherichia coli and Pseudomonas aeruginosa ) and cancer cells (A549, HeLa and PC-3). Most importantly, the possible anticancer mechanism of the complexes was explored by determining the cells morphological changes, intracellular reactive oxygen species (ROS) levels, location in mitochondria, mitochondrial membrane potentials and the expression of Bcl-2 family proteins. The results showed that the complexes could induce apoptosis in HeLa cells through an ROS-mediated mitochondrial dysfunction pathway, which was accompanied by the regulation of Bcl-2 family proteins.
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Materials Research Express
·
2019
·Vol. 6
·期 9
·095315
·
IF 1.449
Huining Zhang,Qing Chang,Jianping Han,Shiming Gao,Zhiguo Wu,Jiawei Hu,Yahong Yang,Zhiqiang Wei,Dengqi Zhang,Zhangpu Peng
In this work, two novel macroporous hydrogel beads (PVA/GO–N and PVA/CS) were prepared to remove Cu2+ and Pb2+ ions in the solution. The maximum Cu2+ sorption capacities on PVA/GO–N and PVA/CS beads were 96.22 and 74.66 mg g−1, while the counterpart sorption capacities of Pb(II) were 278.16 and 144.53 mg g−1, respectively. Isotherm, kinetics and XPS analysis investigation indicated that the sorption processes were controlled by multiple mechanisms. The Cu(II) and Pb(II) removal rates were influenced by the changes of pH, initial dosage, ionic strength, chelator and co-existed ions. The packed-bed sorption column experiments were also carried out to investigate the operating parameters and the potential of the two adsorbents in large scale adsorption systems in practical use. The kinetic model, Thomas equation, was applied to predict dynamic behavior of the fixed bed column for a successful design of a sorption column.
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MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 7
·2325-2331
·
IF 4.58
Huang Xinan,Jiang Hong,Li Yongxin,Sang Lijia,Zhou Huipeng,Shahzad Sohail Anjum,Ibupoto Zafar Hussain,Yu Cong
A sensitive and selective luminescent nanoprobe (referred to as DEPN) is designed for the determination of Cu(II) ions. DEPN shows two emission peaks, one at 602 nm and caused by [Ru(bpy) 3 ] 2+ , the other (peaking at 500 nm) caused by silver nanoclusters (AgNCs). The luminescence of the ruthenium complex is inert and acts as the internal reference signal, while that of the AgNCs is quenched by Cu(II) ions. Under 350 nm photoexcitation, a linear relationship is found between the ratio of emission intensity (I 500 /I 602 ) and the concentration of Cu(II) ions in the 0.1–16 μM range. The detection limit of Cu(II) ions is estimated to be 50 nM. The DEPN was applied to the determination of Cu(II) ions in (spiked) water samples, and to intracellular imaging of Cu(II) in HeLa cells using confocal fluorescence microscopy.
Schematic presentation of a dual-emission photoluminescence nanoprobe for selective Cu 2+ sensing. The emission of the Ag nanoclusters (at 500 nm) is quenched by Cu 2+ , while that of the Ru(bpy) 3
2+ -doped silica nanoparticles (at 602 nm) remains unchanged and serves as a reference.
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ANALYTICAL LETTERS
·
2024
·
IF 1.6
Zheng Chang,Qiqi Zhao,Binghua Yao,Lei Han
Novel electroactive nanotags of Cu(II) functionalized polyethylenimine (PEI)/SiO2 nanoparticles (abbreviated as Cu2+/PEI/SiO2 NPs) were conveniently synthesized using a strong coordination reaction between Cu(II) and the multi-amino groups of PEI. These electroactive nanotags were easily coated on the overoxidized polypyrrole (OPPy) modified Nafion/multi-walled carbon nanotubes (abbreviated as Nafion/MWNTs) electrode surface through Cu-N bonds and strong electrostatic interactions. The Cu2+/PEI/SiO2 NPs@OPPy/MWNTs hybrid nanomaterial was formed without the addition of extra membrane-forming substances. The experimental results demonstrate that the OPPy/MWNTs composite membrane coupled with electrocatalytic Cu(Tris)42+ complexes in tris(hydroxymethyl)aminomethane (Tris)-HCl buffer medium amplified the electrochemical signals of nanotags based on the mutual synergistic effects. As an application, a label-free electrochemical immunosensor for epithelial ovarian cancer biomarker-carbohydrate antigen-125 (CA125) was constructed by covalently immobilizing CA125 antibody onto the hybrid nanomaterial modified electrode. With the increasing concentrations of CA125 antigen, different decreases in the electrochemical signals of the nanotags were observed due to the formation of antigen-antibody immune complexes. The electrochemical immunosensor showed a linear relationship from 0.001 to 500 U·mL−1 for CA125 with a detection limit of 3.4 × 10−4 U·mL−1. In addition, the proposed immunosensor was applied to the determination of CA125 in human serum with satisfactory results.
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Journal of Materials Chemistry B
·
2019
·Vol. 8
·期 5
·919-927
·
IF 5.047
Minghui Zan,Cong Li,Daoming Zhu,Lang Rao,Qian-Fang Meng,Bei Chen,Wei Xie,Xingwang Qie,Li Li,Xiaojiao Zeng,Yirong Li,Wen-fei Dong,Wei Liu
Copper ions (Cu2+) and L-cysteine (L-Cys) in the human body always play critical roles in various physiological processes, while abnormal Cu2+ and L-Cys concentrations in the biological system lead to many diseases. In this manuscript, Si-doped carbon dots (Si-CDs) with near-infrared fluorescence were designed for the detection of Cu2+ and L-Cys through the fluorescence “on–off–on” mode. The carbon dots exhibited not only excellent optical merits including good stability against photobleaching and high chemical stability, but also superior biological compatibility. Interestingly, due to the abundant amino groups distributed on the surface of Si-CDs, they could bind to copper ions to form cupric amine complexes and then quench the fluorescence of Si-CDs due to an electron transfer process. In addition, upon the addition of L-Cys, the FL intensity of Si-CDs could be effectively recovered accompanied with complexation between Cu2+ and the functional groups in L-Cys, due to which Cu2+ was removed from the surface of Si-CDs. Notably, as far as we know, these are the first red-emitting carbon dots for copper ion and L-Cys assays in water samples and human plasma samples. Furthermore, this strategy was successfully applied to the determination of Cu2+ and L-Cys in living systems, demonstrating great practicability in biomedical applications.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Lijun Chen,Chenguang Wang,Guozhao Liu,Guanwen Su,Leping Dang,Hongyuan Wei
Rational utilization of the surface charge property of components is an effective method to prepare heterojunction. The surface of g-C 3 N 4 nanosheets (CNs) and black phosphorous nanosheets (BPs) both exhibit negative charge, which would produce repulsive force to hinder them from approaching each other. Herein, non-noble and low-toxic Cu(II) was selected to harmonize the CNs and BPs together under the interaction of surface charges, and the Cu(II) was reduced in situ to Cu with good conductivity, obtaining the sandwich-like product BPs/Cu/CNs with tight interface and high separation efficiency of photogenerated carriers. The composites exhibited attractive degradation performance for various pollutants under visible light, especially, 95.3 % of ciprofloxacin (10 mg/L, 200 mL) was removed in 60 min with 50 mg of 6BPs/4Cu/CNs as photocatalyst, and the removal ratio can still reach 87.4 % after the fifth reuse with negligible leaching of Cu ions. An unconventional type-II band structure was built in the BPs/Cu/CNs under the drive of internal electric field and mutual attraction of opposite charges, in which the e - from CB of BPs transferred to Cu and then combined with the h + from VB of CNs, leaving the e - from CB of CNs and h + from VB of BPs still work. Despite the same result to that of typical type-II band structure of BPs/CNs, the flow of photogenerated carriers in the BPs/Cu/CNs was more favorable in thermodynamics.
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Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Ge Zhang,Huifen Yang,Tong Zhao,Xuan Li,Yichen Zhou,Song Guo
The thermal adsorption residue (TDR) from oil sludge co-contaminated soil was employed to remove As(III), Zn(II), Cu(II), Cd(II) in aqueous solution. The results showed that the TDR could efficiently neutralize the acid and adapt to the extensive pH. The adsorption of four heavy metals on TDR could be divided into three stages. The maximum adsorption capacity were 86.59, 249.07, 339.88, 322.86 mg·g −1 for As(III), Zn(II), Cu(II), Cd(II), respectively. The coexistence of Zn(II)/Cu(II)/Cd(II) could promote As(III) removal but As(III) led to decreasing of Zn(II)/Cu(II)/Cd(II) adsorption capacity in binary system. There was a significant competitive adsorption on TDR among the three cations which followed the selectivity sequence of Cu(II)>Zn(II)>Cd(II). The SEM-EDS, XRD, FTIR and XPS analyses demonstrated that the As(III) was removed via formation of Ca-As precipitation, and the Zn(II), Cu(II), Cd(II) were removed through precipitating as hydroxides/carbonates/silicates combining with ion exchange. Specially, the Cu(II) mainly precipitated in the form of Cu 4 (SO 4 )(OH) 6 ⋅2H 2 O and Cu 4 (OH) 6 SO 4 under sulfuric acid solution environment. Overall, this study indicates the potential of TDR as a cost-effective adsorbent in acid heavy metals contaminated wastewater treatment .
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