The development of novel selective probes with high sensitivity for the detection of Al3+ is widely considered an important research goal due to the importance of such probes in medicine, living systems and the environment. Here, we describe a new fluorescent probe, N′-(4-diethylamino-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (1), for Al3+. Probe 1 was evaluated in a solution of acetonitrile/water (1:1 v/v). Compared with previously reported probes for Al3+, probe 1 can be synthesized easily and in high yield. A Job plot confirmed that probe 1 is able to complex Al3+ in a 1:1 ratio, and the binding constant was determined to be 4.25×108m−1. Moreover, the detection limit was as low as 6.7×10−9m, suggesting that probe 1 has a high sensitivity. Common coexistent metal ions, such as K+, Co2+, Ca2+, Ba2+, Ni2+, Pb2+, Hg2+, Ce2+, Zn2+, Cd2+, Fe3+, showed little or no interference in the detection of Al3+ in solution, demonstrating the high selectivity of the probe. Finally, the ability of probe 1 to act as a fluorescent probe for Al3+ in living systems was evaluated in Gram-negative bacteria, Escherichia coli, and confocal laser scanning microscopy confirmed its utility. The results of this study suggest that 1 has appropriate properties to be developed for application as a fluorescent probe of Al3+ for use in biological studies. 相似文献
We describe an electrochemical sensor for simultaneous determination of hydroquinone (HQ) and catechol (CC). A glassy carbon electrode (GCE) was modified with gold nanoparticles, L-cysteine, and ZnS/NiS@ZnS quantum dots using a layer-by-layer technique. The materials were characterized by X-ray diffractometry, field emission scanning electron microscopy, and electrochemical impedance and Fourier transform infrared spectroscopy. Cyclic voltammetry and differential pulse voltammetry revealed this modified GCE to represent a highly sensitive sensor for the simultaneous determination of HQ and CC. The anodic peak current for HQ at a working voltage of 80 mV (vs. Ag/AgCl) is related to its concentration in the 0.1 to 300 μM range (even in the presence of 0.1 mM of CC). The anodic peak current for CC at a working voltage of 184 mV is related to its concentration in the 0.5 to 400 μM range (even in the presence of 0.1 mM of HQ). The detection limits (at an S/N ratio of 3) are 24 and 71 nM for HQ and CC, respectively. The modified GCE was successfully applied to the determination of HQ and CC in aqueous solutions and gave satisfactory results.
In order to investigate the effect of the organic ligands on the structures of coordination polymers, two new cadmium(II) coordination polymers based on the different dicarboxylate ligands, namely [Cd2(bpdc)2(DPNDI)2] · 3H2O · NMF ( 1 ) and [Cd(obb)(DPNDI)] ( 2 ) [H2bpdc = biphenyl‐4,4′‐dicarboxylate, H2obb = 4,4′‐oxybis(benzoic acid), DPNDI = N,N′‐bis(4‐pyridyl)‐1,4,5,8‐naphthalene tetracarboxydiimide, and NMF = N‐methylformamide), were synthesized under solvothermal condition and further characterized. Complex 1 shows a twofold interpenetrated pcu topology. Complex 2 possesses a two‐dimensional (2D) layer structure with –ABCD– stacking sequence. Furthermore, the luminescent properties of complexes 1 and 2 are investigated. 相似文献
Two metal‐organic frameworks, [Co2(ABTC)(bimh)(OH)] · 2H2O ( 1 ) and [Co3(ABTC)2(dimb)4]n ( 2 ) [H3ABTC = 3,4′,5‐azobenzenetricarboxylic acid, bimh = 1,1′‐(1,4‐hexanediy)bis(imidazole), dimb = 1,4‐bis(1H‐imidazol‐1‐yl)benzene], were prepared under solvothermal conditions and structurally characterized. Complex 1 demonstrates a complicated 3D (3,8)‐connected tfz‐d net with (43)2(46.617.85) topology. The framework of 2 can be classified as a rare 3D (3,6,6)‐connected net with the Schäfli symbol of (4.62)2(42.610.83)(44.610.8), and exhibits an intriguing self‐penetrating motif. Meanwhile, the thermal stabilities and magnetic properties for 1 and 2 were also probed. 相似文献
A three‐component reaction between an aromatic aldehyde, quinolin‐6‐amine or quinolin‐5‐amine, and tert‐butyl 2,4‐dioxopiperidine‐1‐carboxylate in reflux EtOH gave pyrido phenanthroline derivatives in high yields under catalyst free conditions. The rare C‐H…F hydrogen bond is found in the crystal structure of 6h . 相似文献
Two uranyl complexes based on pyromellitic acid were hydrothermally synthesized, and their X‐ray single‐crystal diffraction structures were determined. Complex [UO2(Hbtec)]–(Himd)+ · H2O ( 1 ) (H4btec = pyromellitic acid, imd = imidazole), is an ionic complex, which shows a typical (4, 4) topological structure in the space. A heterometallic complex, UO2Cu(btec)(phen) ( 2 ) (phen = 1,10‐phenanthroline) results from the reaction of uranyl nitrate and copper(II) bromide with pyromellitic acid. The structure of complex 2 revealed that the chains of UO7 and CuO3N2 units were connected to each other through the carboxyl groups and U=O–Cu interactions to create a two‐dimensional framework. 相似文献
Four ZnII/CdII coordination polymers (CPs) based on 2‐(4‐carboxy‐phenyl)imidazo[4, 5‐f]‐1, 10‐phenanthroline (HNCP) and different derivatives of 5‐R‐1, 3‐benzenedicarboxylate (5‐R‐1, 3‐BDC) (R = NO2, H, OH), [Zn(HNCP)(5‐NO2‐1, 3‐BDC)]n ( 1 ), [Cd(HNCP)(5‐NO2‐1, 3‐BDC)]n ( 2 ), [Zn(HNCP)(1, 3‐BDC)(H2O)2]n ( 3 ), and {[Zn(HNCP)(5‐OH‐1, 3‐BDC)(H2O) · H2O}n ( 4 ) were synthesized under hydrothermal conditions. Compounds 1 – 4 were determined by elemental analyses, IR spectroscopy, and single‐crystal and powder X‐ray diffraction. Compounds 1 and 2 are isomorphous, presenting a 4‐connected uninodal (4, 4)‐sql 2D framework with threefold interpenetration, which are further extended into the three‐dimensional (3D) supramolecular architecture through π ··· π stacking interactions between the aryl rings of 5‐NO2‐1, 3‐BDC. Compared to compound 1 , 3 is obtained by using different reaction temperatures and metal‐ligand ratios, generating a 3D framework with –ABAB– fashion via π ··· π stacking interactions. Compound 4 is a 1D chain, which is further extended into a 3D supramolecular net by hydrogen bonds and π ··· π stacking interactions. The thermogravimetric and fluorescence properties of 1 – 4 were also explored. 相似文献
Based on enzymatic reactions-triggered changes of pH values and biocomputing, a novel and multistage interconnection biological network with multiple easy-detectable signal outputs has been developed. Compared with traditional chemical computing, the enzyme-based biological system could overcome the interference between reactions or the incompatibility of individual computing gates and offer a unique opportunity to assemble multicomponent/multifunctional logic circuitries. Our system included four enzyme inputs: β-galactosidase (β-gal), glucose oxidase (GOx), esterase (Est) and urease (Ur). With the assistance of two signal transducers (gold nanoparticles and acid–base indicators) or pH meter, the outputs of the biological network could be conveniently read by the naked eyes. In contrast to current methods, the approach present here could realize cost-effective, label-free and colorimetric logic operations without complicated instrument. By designing a series of Boolean logic operations, we could logically make judgment of the compositions of the samples on the basis of visual output signals. Our work offered a promising paradigm for future biological computing technology and might be highly useful in future intelligent diagnostics, prodrug activation, smart drug delivery, process control, and electronic applications. 相似文献