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Zhou Y.-H.,Anhui Normal University | Tao J.,Anhui Normal University | Sun D.-L.,Anhui Normal University | Chen L.-Q.,Anhui Normal University | And 3 more authors.

To mimic superoxide dismutase, two new copper(II) complexes, [Cu(bqad)X2] (1, X = Cl; 2, X = Br; where bqad = N,N′-bis(2-quinolinylmethyl)amantadine), have been synthesized and characterized by elemental analysis, electronic absorption, IR and single crystal X-ray diffraction. The copper ions in 1 and 2 have a penta-coordination geometry, composed of three nitrogen atoms from one bqad ligand and two halide anions. The complexes showed quasi-reversible one-electron Cu(II)/Cu(I) redox waves, as determined by cyclic voltammetry. By using an NBT assay at pH 7.8, the superoxide dismutase (SOD)-like activity (IC50) of 1 and 2 were measured to be 0.43 and 0.32 μM, respectively. The enhancement in the SOD-like activity of 2 can be ascribed to the formation of the species [Cu(bqad)2(H2O)2]2+ in aqueous solution due to the two labile bromine ions. Furthermore, DFT calculations were performed in order to understand the relationship between the structures and activities of the mimics. © 2014 Elsevier Ltd. All rights reserved. Source

Miao H.,Fuyang Normal College | Miao H.,Anhui Province Key Laboratory for Degradation and Monitoring of Pollution of the Environment | Miao H.,Key Laboratory of Functional Molecular Solids | Xia J.,Fuyang Normal College | And 9 more authors.
Faguang Xuebao/Chinese Journal of Luminescence

AgNbO3/graphene nanocomposites were synthesized via the technique of solid-solid grinding and subsequent sintering process. Surface structures and optical properties of the prepared materials were characterized by transmission electron microscopy and UV-Vis diffuse reflection spectroscopy. The results indicate that band-gap of AgNbO3 is lowered upon compositing with graphene nanoparticles, thereby giving an absorption in a large range of wavelengths. Degradation of methyl orange (MO) is carried out to evaluate the photocatalytic activity of AgNbO3/graphene nanocomposites under visible light irradiation. Compared with pure AgNbO3, AgNbO3/graphene composites exhibit significantly enhanced photocatalytic activity for MO. Moreover, AgNbO3/graphene (2:1) obtained at 300 ℃ exhibits the highest degradation degree of MO after an irradiation of 120 min with apparent kapp of 0.034 min-1, which is about 10 times than that of the pure AgNbO3. The tests of radical scavengers confirm that ·O2 - and h+ are the main reactive species for the degradation of MO. © 2016, Science Press. All right reserved. Source

Jiang H.,Key Laboratory of Chemical Biosensing | Jiang H.,Key Laboratory of Functional Molecular Solids | Jiang H.,Anhui Normal University | Zhang X.,Key Laboratory of Chemical Biosensing | And 6 more authors.
Biosensors and Bioelectronics

Due to terbium's unique photophysical properties, nucleic-acid-sensitized terbium (DNA/Tb3+) bioluminescent system becomes a potential candidate for the fabrication of DNA biosensors. However, the low sensitivity of DNA/Tb3+ bioluminescent system limits its development. In this paper, a strategy combining autocatalytic multi-cycle-amplification (including exonuclease III (exo III)-aided and Zn2+-requiring DNAzyme-assisted target recycling amplifications) and magnetic nanoparticles assisted-background-lowering to improve the sensitivity of DNA/Tb3+ bioluminescent system is presented for sensitive detection of target DNA (tDNA). The DNA/Tb3+ bioluminescent system was investigated by ultraviolet-visible (UV-vis) absorption and luminescence spectra. The possible conjugation mechanism and mode of DNA with Tb3+ were discussed. The autocatalytic multi-cycle-amplification effect was investigated by the comparison of the luminescence. The carboxylation-functionalized Fe3O4-magnetic nanoparticles (MNPs) were characterized and its role in background lowering was proved. As a result, with the designed protocol, the detection limit for the tDNA detection reached a low level to aM, which is especially exciting for the DNA/Tb3+ bioluminescent system. In the process, due to the separation effect of MNPs, the assay solution was purified to avoid the nonspecific luminescence of DNA/Tb3+, not only lowering the background signal greatly (about five times lower than that without the use of MNPs but also improving the reproducibility and stability. We hope that our attempt in this field will not only extend the application of DNA/Tb3+ luminescent system in biosensing areas but also open the road to adaptation of the protocols to other related analytes. © 2015. Source

Wang G.,Key Laboratory of Chemical Biosensing | Wang G.,Key Laboratory of Functional Molecular Solids | Wang G.,Anhui Normal University | Wang G.,Hefei University of Technology | And 12 more authors.
Biosensors and Bioelectronics

In the present study, based on a dual hairpin DNA structure, a novel system of electrically contacted enzyme and its signal amplification for ultrasensitive detection of Hg 2+ was demonstrated. In the presence of Hg 2+, with the interaction of thymine-Hg 2+-thymine (T-Hg 2+-T), DNA sequence dully labeled with ferrocene (Fc) at 5' end and horseradish peroxidase (HRP) at 3' end, hybridized to the capture probe and formed the dual hairpin structure on the electrode. Fc unit acts as a relay that electrically contacts HRP with the electrode and activates the bioelectrocatalyzed reduction of H 2O 2. And based on the bioelectrocatalyzed signal amplification of the presented system, Hg 2+ could be quantitatively detected in the range of 10 -10-10 -6M with a low detection limit of 52pM. And it also demonstrated excellent selectivity against other interferential metal ions. © 2012 Elsevier B.V. Source

Zhou Y.-H.,Anhui Normal University | Zhou Y.-H.,Key Laboratory of Functional Molecular Solids | Tao J.,Anhui Normal University | Lv Q.-C.,Anhui Normal University | And 6 more authors.
Inorganica Chimica Acta

Four copper(II) complexes (1, [Cu(L1)(CH3COO-)](ClO4); 2, [Cu(L2)2](ClO4)2; 3, [Cu(L2)2Br]Br and 4, [Cu2(L2)2(CH3COO-)4]; L1 = N,N'-bis(2-pyridylmethyl)amantadine, L2 = (pyridyl-2-amino)carbonyl adamantane) have been synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction. Copper ions in 1 and 2 have the distorted planar coordination configuration. The coordination geometry of 3 and 4 can be described as the distorted tetragonal pyramid. The adjacent two copper ions in 4 are bridged by four acetate anions. By using NBT assay at pH 7.8, the superoxide dismutase (SOD)-like activity (IC50) of 1-4 were measured to be 0.21, 0.15, 0.22 and 0.90 μM, respectively. The enhancement in SOD-like activity of 2 suggests that the hydrogen bonds provided by the amide groups and the coordination configuration play an important role on the dismutation of O2 -. Moreover, electrochemistry of complexes was determined by the cyclic voltammetry. ©2014 Elsevier B.V. All rights reserved. Source

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