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Coordination geometry-induced optical imaging of <scp>l</scp> -cysteine in cancer cells using imidazopyridine-based copper( <scp>ii</scp> ) complexes
摘要: Overexpression of cysteine cathepsins proteases has been documented in a wide variety of cancers, and enhances the L-cysteine concentration in tumor cells. We report the synthesis and characterization of copper(II) complexes [Cu(L1)2(H2O)](SO3CF3)2, 1, L1 = 3-phenyl-1-(pyridin-2-yl)imidazo[1,5-a]pyridine, [Cu(L2)2(SO3CF3)]SO3CF3, 2, L2 = 3-(4-methoxyphenyl)-1-pyridin-2-yl-imidazo[1,5-a]pyridine, [Cu(L3)2(H2O)](SO3CF3)2, 3, L3 = 3-(3,4-dimethoxy-phenyl)-1-pyridin-2-yl-imidazo[1,5-a]pyridine and [Cu(L4)2(H2O)](SO3CF3)2, 4, L4 = dimethyl-[4-(1-pyridin-2-yl-imidazo[1,5-a]pyridin-3-yl)phenyl]amine as 'turn-on' optical imaging probes for L-cysteine in cancer cells. The molecular structure of complexes adopted distorted trigonal pyramidal geometry (τ, 0.68–0.87). Cu–Npy bonds (1.964–1.989 ?) were shorter than Cu–Nimi bonds (2.024–2.074 ?) for all complexes. Geometrical distortion was strongly revealed in EPR spectra, showing gk (2.26–2.28) and Ak values (139–163 × 10?4 cm?1) at 70 K. The d–d transitions appeared around 680–741 and 882–932 nm in HEPES, which supported the existence of five-coordinate geometry in solution. The Cu(II)/Cu(I) redox potential of 1 (0.221 V vs. NHE) was almost identical to that of 2 and 3 but lower than that of 4 (0.525 V vs. NHE) in HEPES buffer. The complexes were almost non-emissive in nature, but became emissive by the interaction of L-cysteine in 100% HEPES at pH 7.34 via reduction of Cu(II) to Cu(I). Among the probes, probe 2 showed selective and efficient turn-on fluorescence behavior towards L-cysteine over natural amino acids with a limit of detection of 9.9 × 10?8 M and binding constant of 2.3 × 105 M?1. The selectivity of 2 may have originated from a nearly perfect trigonal plane adopted around a copper(II) center (~120.70°), which required minimum structural change during the reduction of Cu(II) to Cu(I) while imaging Cys. The other complexes, with their distorted trigonal planes, required more reorganizational energy, which resulted in poor selectivity. Probe 2 was employed for optical imaging of L-cysteine in HeLa cells and macrophages. It exhibited brighter fluorescent images by visualizing Cys at pH 7.34 and 37 °C. It showed relatively less toxicity for these cell lines as ascertained by the MTT assay.
关键词: optical imaging,cancer cells,turn-on fluorescence,imidazopyridine,L-cysteine,Copper(II) complexes
更新于2025-11-21 11:08:12
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Fluorescent sensor for copper(II) ion based on coumarin derivative and its application in cell imaging
摘要: A novel fluorescent sensor CHT was designed based on the excellent optical properties of coumarin derivatives. It was synthesized by Schiff base reaction connected by 7-(N,N-diethylamino) coumarin-3-aldehyde and 2-hydrazinobenzothiazole. The sensor CHT displayed exhibited a significant fluorescence quenching at 540 nm upon the addition of Cu2+ ions. And the sensor exhibited good sensitivity, fast response time, high selectivity for Cu2+ ions in the presence of other important relevant metal ions. In addition, CHT fluorescent sensor was successfully applied for fluorescent imaging of Cu2+ ions in A549 and MCF-7 cells, demonstrating its potential applications in live cell imaging.
关键词: fluorescent sensor,coumarin,cell imaging,copper(II) ion
更新于2025-09-23 15:23:52
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Bonded-luminescent foam based on europium complexes as a reversible copper (II) ions sensor in pure water
摘要: Developing novel lanthanide complexes to rapidly and reliably sensing Cu2+ ions in pure water is highly challenging. Here, a series long luminescence lifetime luminescent Eu-complex polyurethane foams (Eu-PUFs) porous material by simple one-step co-polycondensation reaction has been successfully assembled. The photoluminescence (PL) results indicated that the pure red emission from Eu3+ ions is selectively quenched upon addition of Cu2+ ions, and barely any interference by other metal ions in pure water, thus making Eu-PUFs as a potential Cu2+ ions sensing material. The original luminescent intensity of Eu3+ ions located 617nm can be recovered about 84% by washing of ethylenediaminetetraacetic acid (EDTA) there times, indicating the sensing ability of Eu-PUFs is highly reversible. Due to the probe molecules Eu (TTA)3 ? Phen-NH2 was bonded into Eu-PUFs through covalent bond linker, so the Eu-PUFs sensors can be utilized to detection of Cu2+ ions in pure water multiple times (more than 20 times) without much effect on the sensitivity, and the limitation of detection (LOD) for Cu2+ in pure water is as low as 0.28 μM. All above mentioned results revealed these Eu-PUFs are excellent and potential Cu2+ ions sensing material in pure water and will be widely used in analytical and biological application fields.
关键词: copper (II) ions detection,fluorescence quenching,Europium complexes,Bonded-luminescent foam
更新于2025-09-23 15:22:29
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Photocatalytic Oxyamination of Alkenes: Copper(II) Salts as Terminal Oxidants in Photoredox Catalysis
摘要: A photocatalytic method for the oxyamination of alkenes using simple nucleophilic nitrogen atom sources in place of prefunctionalized electrophilic nitrogen atom donors is reported. Copper(II) is an inexpensive, practical, and uniquely effective terminal oxidant for this process. In contrast to oxygen, peroxides, and similar oxidants commonly utilized in non-photochemical oxidative methods, the use of copper(II) as a terminal oxidant in photoredox reactions avoids the formation of reactive heteroatom-centered radical intermediates that can be incompatible with electron-rich functional groups. As a demonstration of the generality of this concept, it has been shown that diamination and deoxygenation reactions can also be accomplished using similar photooxidative conditions.
关键词: copper(II),photoredox catalysis,alkenes,oxyamination,terminal oxidant,photocatalytic
更新于2025-09-23 15:21:21
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Hydrophilic Truxene Derivative as a Fluorescent off-on Sensor for Copper (II) Ion and Phosphate Species
摘要: A new symmetrical truxene derivative (TP3) containing three dipicolylamino peripheral groups is successfully synthesized in four synthetic steps with an overall yield of 42%. This hydrophilic fluorescent compound exhibits a maximum absorption wavelength at 375 nm, an emission maximum at 474 nm with an outstanding 58% quantum efficiency in THF-HEPES buffer mixture. The compound shows a highly selective fluorescence quenching towards Cu(II) ion with a detection limit of 0.06 ppm. The results from mass spectrometry and Job plot indicate that a 1:1 complex between TP3 and Cu(II) ion is responsible for the signal quenching. Interestingly, this TP3-Cu complex can be used as a turn-on sensor for hydrogen phosphate and nucleoside phosphates. The limit of detection for hydrogen phosphate is estimated at 8.7 nM. The signal restoration involves a displacement of TP3 in the complex by the phosphates which have strong coordination abilities with Cu(II) ion.
关键词: Truxene,Fluorescence,Phosphate,Sensor,Picolylamine,Copper (II) ion
更新于2025-09-19 17:15:36
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A novel coumarin-based fluorescent probe for sensitive detection of copper(II) in wine
摘要: A novel coumarin-based fluorescent probe (probe 1) for the detection of copper(II) was developed. The fluorescence intensity of probe 1 showed a linear relationship with the concentration of copper(II) in the range 0–16 μM (0–1.02 mg/L) and the limit of detection was 62 nM (3.94 μg/L). The luminescence of probe 1 at the maximum allowable amounts of copper(II) in wine and water could be observed with the naked eye under a 365-nm ultraviolet lamp. Moreover, probe 1 was successfully used for the qualitative and quantitative detection of copper(II) in wine.
关键词: fluorescent probe,red wine,Copper(II)
更新于2025-09-19 17:15:36
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An Optical Fiber Chemical Sensor for the Detection of Copper(II) in Drinking Water
摘要: Highly sensitive plasmonic optical fiber platforms combined with receptors have been recently used to obtain selective sensors. A low-cost configuration can be obtained exploiting a D-shaped plastic optical fiber covered with a multilayer sensing surface. The multilayer consists of a gold film, functionalized with a specific receptor, where the surface plasmon resonance (SPR) occurs. The signal is produced by the refractive index variation occurring as a consequence of the receptor-to analyte binding. In this work, a selective sensor for copper(II) detection in drinking water, exploiting a self-assembled monolayer (SAM) of d,l-penicillamine as the sensing layer, has been developed and tested. Different concentrations of copper(II) in NaCl 0.1 M solutions at different pH values and in a real matrix (drinking water) have been considered. The results show that the sensor is able to sense copper(II) at concentrations ranging from 4 × 10?6 M to 2 × 10?4 M. The use of this optical chemical sensor is a very attractive perspective for fast, in situ and low-cost detection of Cu(II) in drinking water for human health concerns. Furthermore, the possibility of remote control is feasible as well, because optical fibers are employed.
关键词: Optical chemical sensors,surface plasmon resonance,copper(II),drinking water,human health
更新于2025-09-16 10:30:52
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TG-FTIR coupled analysis to predetermine effective precursors for laser-activated and electroless metallized materials
摘要: Copper compounds can be used as additives to elaborate polymer materials, which after laser-induced ablation can be directly metallized on the irradiated surface area. In this work, three [Cu(l-tyr)2]n (l-tyr = l-tyrosine) (A), [Cu(bpy)3][CrO4]·7.5H2O (bpy = 2,2′-bipyridine) (B) and [Cu(bpy)2(O2SO2)]·CH3OH (C) copper(II) complexes were evaluated. The complexes were mixed at 20 mass% with polyurethane resin to form the coatings. The coatings were irradiated with ArF excimer laser and electroless metallized. It was found that only complex A was effective metallization precursors. Thermal properties of the copper(II) complexes were considered as crucial for defining effective precursors. TG-FTIR coupled analysis was applied to predetermine thermal properties of the compounds, which can be responsible for effective metallization. It was found that the main reason for unsuccessful metallization of the coatings containing complexes B or C was release of lattice H2O or CH3OH molecules in crystal structures, respectively, which affected ablation of the coatings. Appropriate model of laser ablation was also proposed.
关键词: Copper(II) complexes,Polymer coating,Electroless metallization,Laser modification,TG-FTIR coupled analysis
更新于2025-09-11 14:15:04
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A Combined Experimental and Theoretical Investigation on Organic Cation Dichlorocopper (II): Structural Characterization, Hirshfeld Surface Analysis, Spectroscopic Properties and DFT Calculation
摘要: The (ethylenediamine) dichlorocopper(II) complex, {[Cu(en)]Cl2}n(en:C2H8N2), was synthesized by hydrothermal technique. The X-ray structure of {[Cu(en)]Cl2}n shows that the compound crystallizes as a one dimensional chain with one chlorine that is non-bridging and the other chlorine which is triply bridging. It crystallizes at room temperature in the centrosymmetric space group P21/m. The structure of {Cu(en)Cl2}n was originally reported by Kumara et al. The surrounding copper is best described as distorted octahedral. The crystal structure was stabilized with an extensive network of N-H…Cl classical hydrogen bond interactions. The investigation on that close intermolecular interactions between the molecules via Hirshfeld surface analyses is presented to reveal subtle differences and similarities in the crystal structures. The decomposition of the fingerprint plot area provides a percentage of each intermolecular interaction, allowing for a quantified analysis of close contacts within the crystal. The optimized molecular structure and vibrational spectra were calculated by the Density Functional Theory (DFT) method using the B3LYP function with the LanL2DZ basis set. Good consistency is found between the calculated results and the experimental structure, FT-IR, and FT-Raman spectra. The detailed interpretation of the vibrational modes was carried out. Optical transmission measurements performed on thin films of {[Cu(en)]Cl2}n revealed two absorption bands at 3.64 eV and 1.907 eV. The calculated HOMO-LUMO energies reveal that charge transfer occurs within the molecule.
关键词: Optical absorption,Synthesis hydrothermal,Complex copper (II),Hirchfeld surface analysis,Crystal structure,DFT vibrational assignment
更新于2025-09-09 09:28:46
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Molecular electronic spin qubits from a spin-frustrated trinuclear copper complex
摘要: The trinuclear copper(II) complex [Cu3(saltag)(py)6]ClO4 (H5saltag = tris(2-hydroxybenzylidene)triaminoguanidine) was synthesized and characterized by experimental as well as theoretical methods. This complex exhibits a strong antiferromagnetic coupling (J = (cid:2)298 cm(cid:2)1) between the copper(II) ions, mediated by the N–N diazine bridges of the tritopic ligand, leading to a spin-frustrated system. This compound shows a T2 coherence time of 340 ns in frozen pyridine solution, which extends to 591 ns by changing the solvent to pyridine-d5. Hence, the presented compound is a promising candidate as a building block for molecular spintronics.
关键词: antiferromagnetic coupling,trinuclear copper(II) complex,molecular spintronics,spin-frustrated system
更新于2025-09-04 15:30:14