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A new benzimidazole-based selective and sensitive ‘on-off’ fluorescence chemosensor for Cu <sup>2+</sup> ions and application in cellular bioimaging
摘要： Two new twinborn benzimidazole derivates (L and A), which bonded pyridine via the ester space on the opposite and adjacent positions of the benzene ring of benzimidazole respectively, were designed and synthesized. Compound L displayed fluorescence quenching response only towards copper(II) ions (Cu2+) in acetonitrile solution with high selectivity and sensitivity. However, compound A presented 'on–off' fluorescence response towards a wide range of metal ions to different degrees and did not have selectivity. Furthermore, compound L formed a 1:1 complex with Cu2+ and the binding constant between sensor L and Cu2+ was high at 6.02 × 104 M?1. Job's plot, mass spectra, IR spectra, 1H‐NMR titration and density functional theory (DFT) calculations demonstrated the formation of a 1:1 complex between L and Cu2+. Chemosensor L displayed a low limit of detection (3.05 × 10?6 M) and fast response time (15 s) to Cu2+. The Stern–Volmer analysis illustrated that the fluorescence quenching agreed with the static quenching mode. In addition, the obvious difference of L within HepG2 cells in the presence and absence of Cu2+ indicated L had the recognition capability for Cu2+ in living cells.
关键词： fluorescence chemosensor,benzimidazole,cell imaging,copper ion
更新于2025-09-23 15:23:52
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Atomistic modeling of resistivity evolution of copper nanoparticle in intense pulsed light sintering process
摘要： In this work, the intense pulsed light (IPL) sintering process of copper nanoparticle ink is simulated using molecular dynamics (MD) method. First, the neck size growth between the two copper nanoparticles during the IPL sintering process is computed. The resultant electrical resistivity is then calculated by substituting the neck size into the Reimann-Weber formula. Overall, a rapid decrease of electric resistivity is observed in the beginning of the sintering, which is caused by quick neck size growth, followed by a gradually decrease of resistivity. In addition, the correlation of the simulated temperature dependent resistivity is similar to that of the experimentally measured resistivity. The MD model is an effective tool for designers to optimize the IPL sintering process.
关键词： Molecular dynamics,Nanoparticle,Electrical resistivity,Intense pulsed light,Copper
更新于2025-09-23 15:23:52
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Low-temperature dark anneal as pre-treatment for LeTID in multicrystalline silicon
摘要： Light and elevated temperature induced degradation (LeTID) is currently a severe issue in crystalline silicon photovoltaics, which has led to numerous efforts to both understand the mechanism and to mitigate it. Here we show that a low-temperature dark anneal performed as the last step in typical solar cell processing influences greatly LeTID characteristics, both the strength of the degradation and the degradation kinetics. While a relatively short anneal in the temperature range of 200–240 °C can be detrimental to LeTID by doubling the degradation intensity, an optimized anneal at 300 °C shows the opposite trend providing an efficient means to eliminate LeTID. Furthermore, we show that the simulated recombination activity of metal precipitation and dissolution during the dark anneal correlates with the experiments, suggesting a possible explanation for the LeTID mechanism.
关键词： PERC,Precipitation,Multicrystalline silicon,Minority-carrier lifetime,LeTID,Copper in silicon
更新于2025-09-23 15:23:52
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Effect of Na doping on structural and optical properties in Cu2ZnSnS4 thin films synthesized by thermal evaporation method
摘要： Quaternary chalcogenide Cu2ZnSnS4 (CZTS) compound, a potential material for application as absorber layer in thin film solar cells, is synthesized by direct melting of the constituent elements taken in stoichiometry compositions. Alkali element Na was incorporated into CZTS thin films synthesized by thermal evaporation method, in order to further improve the structural and optical properties. X-Ray diffraction (XRD), Raman spectroscopy, Energy dispersive spectrometry and optical spectrophotometry were used to characterise the phase purity and optical properties. It showed that the diffusion of Na ions is uniform in the films after annealing. XRD analysis showed that CZTS films possess polycrystalline structure with [221] preferred orientation. Na ions incorporation in CZTS thin films could improve the cristallinity, the graine size and the absorption coefficient. For CZTS: Na 5%, optical results revealed higher absorption coefficient (>105 cm-1) and direct optical band gap of 1.56 eV with p-type conductivity.
关键词： Semiconductors,Sodium doping,Structural properties,Optical properties,Copper zinc tin sulfide,Thin films,Thermal evaporation
更新于2025-09-23 15:23:52
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Coordination Polymers Based on Organic–Inorganic Hybrid Rigid Rod Comprising a Backbone of Anderson-Evans POMs
摘要： To construct polyoxometalates coordination polymers (PCPs), we prepared two pyridine ligand functionalized Anderson POMs: (TBA)3[MnMo6O18((OCH2)3CN=CH-4-Py)2]·DMF ((TBA)3POM-1, TBA = tetrabutyl ammonium, Py = pyridine) and (TBA)3[MnMo6O18((OCH2)3CN=CH-3-Py)2] ((TBA)3POM-2) via the post-functionalization of (TBA)3[MnMo6O18((OCH2)3CNH2)2] (Anderson-NH2) by 4-pyridinealdehyde and 3-pyridinealdehyde, respectively. They are characterized using X-ray single crystal diffraction, MALDI-TOF MS, ESI MS, FT-IR, UV-Vis and 1H NMR . The self-assembly of (TBA)3POM-1 and [Cu(PPh3)2(CH3CN)2]ClO4 (CuP2) in the mole ratios of 1 : 2 and 1 : 3, both gave the same 1D double chain with the molecular formula of (NBu4)n{[Cu(PPh3)2]2(POM-1)}n (7.5DMF)n (1). On the contrary, the self-assembly of (TBA)3POM-2 and CuP2 in the mole ratio of 1:2 yields a 2D coordination polymer of (TBA)n{[Cu(PPh3)2]2(POM-2)}n·(2DMF)n (2), while that self-assembly process in the mole ratio of 1:3 results in different 2D coordination polymer of {[Cu(PPh3)2]3(POM-2)·(CH3CN)}n·(5CH3CN)n (3). Compounds 1-3 can keep their skeleton structures below 230oC. They exhibit intense green emission (496nm for 1; 537nm for 2; 530nm for 3) by ultra-violet irradiation (327nm for 1; 303nm for 2; 331nm for 3), which can be tentatively ascribed as ILCT with metal perturbation.
关键词： Luminescence,Polyoxometalates,Pyridine,Coordination Polymer,Copper (I)
更新于2025-09-23 15:23:52
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Copper-doped hybrid Agx–Auy@ZnO nanoparticles and their enhanced photocatalytic activities
摘要： In this paper, we report on the simple polyol synthesis of copper-doped hybrid Agx–Auy@ZnO photocatalysts. The obtained samples have been characterized by X-ray diffraction, UV–Vis diffuse reflectance spectroscopy, transmission electron microscopy and an N2 adsorption study. The experiment results show that Ag, Au and Ag–Au alloy nanoparticles (NPs) successfully load onto the surface of the assembled Cu-doped ZnO. The photocatalytic performances of Cu-doped Agx–Auy@ZnO nanomaterials have been tested using diuron herbicide as a model contaminant under simulated solar light irradiation. The addition of Ag and/or Au nanoparticles to doped ZnO was strongly beneficial to the rate constant displaying a volcano-like pattern as a function of the Ag and Au content. A maximum pseudo-first-order rate constant of 18.55 × 10?3 min?1, 22.70 × 10?3 min?1 and 24.74 × 10?3 min?1 was achieved on Cu-doped Ag0.3@ZnO, Au0.5@ZnO and Ag0.5–Au0.3@ZnO respectively. The Cu-doped Ag0.5–Au0.3@ZnO bimetallic nanoparticles show the highest photocatalytic activity due to the synergistic effect by effective electron transfer.
关键词： Hybrid photocatalyst,Copper-doped,Diuron,Water treatment,Polyol process,One pot,Zinc oxide,Gold,Photocatalysis,Solar light,Silver
更新于2025-09-23 15:23:52
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Quantitative control and identification of copper species in Cu–SAPO-34: a combined UV–vis spectroscopic and H2-TPR analysis
摘要： A series of Cu–SAPO-34 catalysts with different copper contents were prepared using a modified ion-exchange method, i.e., impregnation–activation. Controlled amounts of well-dispersed active copper species and integrated physical properties were obtained by this method. The Cu–SAPO-34 catalysts retained the CHA structure, high specific surface area, and pore volume of the H–SAPO-34. Based on a combined analysis of UV–vis spectra and H2-TPR, these common laboratory techniques enabled the identification of the different copper species present in the catalysts. Only isolated copper ions balanced by two framework charges were present in the catalysts at copper contents ≤ 0.8 wt%. With increasing the Cu content, isolated Cu2+ ions charge-balanced by one negative charge became dominant. Further higher Cu contents could result in formation of copper oxides after consumption of all ion-exchange sites.
关键词： Cu–SAPO-34,Copper species,NH3-SCR,H2-TPR,Impregnation–activation
更新于2025-09-23 15:23:52
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Q-graphene-scaffolded covalent organic frameworks as fluorescent probes and sorbents for the fluorimetry and removal of copper ions
摘要： Metal-free fluorescent covalent organic frameworks (COFs) were synthesized initially with Q-Graphene (QG) scaffolds by the one-step covalent reactions of melamine-aldehyde and phenol-aldehyde poly-condensations using paraformaldehyde. It was discovered that onion-like hollow QG, which consists of multi-layer graphene and different carbon allotropes having a high proportion of folded edges and surface defects, could endow the scaffolded COFs with enhanced green fluorescence and environmental stability. Unexpectedly, they could exhibit the powerful absorption for Cu2+ ions resulting in the specific quenching of fluorescence. A fluorimetric strategy with QG-scaffolded COFs was thereby developed to probe Cu2+ ions separately in blood and wastewater with the linear concentration ranges of 0.0010 - 10.0 μM (limit of detection of 0.50 nM) and 0.0032 - 32.0 μM (limit of detection of 2.4 nM), respectively, promising the potential applications for the field-applicable monitoring of Cu2+ ions in the clinical and environmental analysis fields. In addition, the prepared COFs sorbents were employed to absorb Cu2+ ions in wastewater showing high removal efficiency. More importantly, such an one-pot fabrication route with hollow QG scaffolds may be tailorable extensively for the preparation of a variety of metal-free multifunctional COFs with enhanced fluorescence, water solubility, environmental stability, and metal removal capability.
关键词： Q-Graphene Scaffold；Covalent Organic Frameworks；Fluorescent Analysis；Removal Sorbents；Copper Ions
更新于2025-09-23 15:23:52
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Determination of prostate cancer biomarker acid phosphatase at a copper phthalocyanine-modified screen printed gold transducer
摘要： In this work, a novel sensor based on immobilized copper phthalocyanine, 2,9,16,23-tetracarboxylic acid-polyacrylamide (Cu(II)TC Pc-PAA) was developed for determination of acid phosphatase (ACP) levels in nanomolar quantities. Detection was based on the measurement of enzymatically generated phosphate, with initial studies focused on phosphate detection at a Cu(II)TC Pc-PAA modified screen-printed gold transducer. The sensor was characterised in relation to operational performance (pH, response time, stability, linearity, and sensitivity) and common anionic interferents (nitrate, sulphate, chloride, and perchlorate). The functionalised surface also facilitated rapid detection of the enzyme bi-product 2-naphthol over the range 5-3000 μM. Quantitation of ACP was demonstrated, realising a linear response range of 0.5-20 nM and LOD of 0.5 nM, which is within the clinical range for this prostate cancer biomarker.
关键词： phosphate,Copper phthalocyanine,acid phosphatase,naphthol,gold screen-printed electrode.
更新于2025-09-23 15:23:52
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Synthesis, characterization and DFT analysis of new phthalocyanine complexes containing sulfur rich substituents
摘要： Nine new tetrasubstituted metallophthalocyanines (MPc) bearing sulfur rich substituents on peripheral positions were synthesized and fully characterized. The new MPc compounds contain Co2+, Ni2+ and Cu2+. The photochemical and electrochemical properties of the new molecules were investigated. In addition to this investigation, a comparative study took place on the effect of the type of terminal ligand on properties of the MPc compound. Theoretical studies (DFT) were, also carried out in order to support the corresponding experimental results.
关键词： Cobalt,Copper,Nickel,Microwave synthesis,Phthalocyanines,DFT calculations
更新于2025-09-23 15:23:52