BIOCHEMICAL ENGINEERING JOURNAL
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2018
·
IF 3.226
Amjad Hussain Memon,Runsheng Ding,Qipeng Yuan,Hao Liang,Yun Wei
Enhancing activity of multiple enzymes by co-localization are key topics in bionanotechnology. Herein, we introduce a facile co-immobilization of glucose oxidase (GOx) and horseradish peroxidase (HRP) in the matrix of Cu (copper) and GMP (guanosine 5′-monophosphate). The multienzyme system by co-immobilizing GOx&HRP observed with high catalytic efficiency and stability compared with free GOx&HRP enzymes. GOx&HRP@Cu/GMP stability was observed 40% increased at pH 3 and thermal stability more than 70% determined at 90 ᵒ C. The storage stability was sustained 8 times higher than free enzymes after thirteen days and reusability after reacting eight times with fresh substrate retains 90% relative activity. Further, GOx&HRP@Cu/GMP demonstrated an excellent selectivity in the development of glucose biosensor and exhibited good resistance against the protease enzymes and organic solvents. The obtained results emphasize that co-immobilization of GOx&HRP in the matrix of Cu/GMP could be an efficient protocol for the biocatalyst encapsulation.
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COLLOIDS AND SURFACES B-BIOINTERFACES
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2018
·
IF 3.997
Hai-Bo Wang,Li-Hong Ma,Bi-Yun Fang,Yuan-Di Zhao,Xue-Bin Hu
This study has reported that a GR-5 DNAzyme based lead ion strip biosensor could exhibit an enhanced specificity with the assistance of graphene oxide (GO). This enhancement results from the specific π-stacking interaction between the ribose rings of the nucleobases and the carbon hexagons in GO which can reduce the false positive interference by removing unhybridized ssDNA during the annealing of GR-5 DNAzyme. Meanwhile, conjugate pad was sprayed with two kinds of AuNP-DNA probes, and nitrocellulose membrane test zone and control zone were immobilized with two kinds of biotin-DNA probes, respectively. The limit of detection of this strip biosensor was estimated to be about 0.05 nM (S/N = 3) and 1 nM (with naked eyes) with a linear range from 0.01 to 100 μM. Furthermore, the strip biosensor exhibited excellent selectivity toward Pb 2+ in the presence of other divalent metal ions. For real soil samples, the obtained recoveries were in the range from 91.5% to 113.1%.
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HIGH PERFORMANCE POLYMERS
·
2018
·
IF 1.047
Huagao Wang,Hailong Tang,Junyi Yang,Youbing Li
Poly(arylene ether nitrile)s (PAENs) play an important role in special engineering materials owing to their excellent mechanical strength and superior thermal stability. In this study, PAEN and carboxyl-functionalized poly(arylene ether nitrile) (CPAEN) were successfully synthesized and their thermal parameters were determined through thermogravimetric analysis and differential scanning calorimetry to investigate the thermal decomposition kinetics and thermal stability. The results indicate that both PAEN and CPAEN exhibited high glass transition temperature and initial decomposition temperature. Meanwhile, the effects of the side groups on the thermal stability and the decomposition kinetic parameters of PAEN and CPAEN under nitrogen were discussed systematically. The kinetic parameters of PAEN and CPAEN were determined using the Kissinger and Ozawa methods, respectively. It reveals that the activation energy (E) values of PAEN obtained using the Kissinger and Ozawa methods were 192.45 and 206.63 kJ/mol, and the corresponding E values of CPAEN were 161.20 and 162.72 kJ/mol, respectively. The thermal decomposition mechanism of PAEN and CPAEN obtained from Coats–Redfern methods goes for F 3 and D 1 models, respectively.
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SENSORS AND ACTUATORS B-CHEMICAL
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2018
·
IF 5.667
Di Zhu,Dongxuan Guo,Lulu Zhang,Lichao Tan,Haijun Pang,Huiyuan Ma,Mo Zhai
Heteropolyacids (PMo 6 W 6 ) and ferrocene (Fc) were assembled on the glassy carbon electrode for the first time by electrodepositon method, and further combined with reduced graphene oxide (RGO) through the layer-by-layer self-assembly technology, developing a novel non-enzymatic nanocomposite for xanthine (XA) detection. The detection signal of XA was greatly amplified on the Fc-PMo 6 W 6 /RGO nanocomposite modified electrode due to coexist of these three active components. As ferrocene and PMo 6 W 6 all have relatively good electrochemical reversibility, fast electron transfer ability and generation of stable redox forms, meanwhile RGO can enlarge the active surface area of the electrode, increase the conductivity and load of ferrocene and PMo 6 W 6 . Under the optimized conditions, the developed nanocomposite modified electrode displayed superb sensing property towards xanthine with a widely linear range from 5.00 × 10 −8 ∼ 2.03 × 10 -3 M, along with a relatively low detection limit of 1.01 × 10 -8 M. The modified electrode has good stability as it is prepared by the smart combination electrodeposition and layer-by-layer self-assembly. Additionally, the nanocomposite was applied in detecting xanthine in actual samples with acceptable results, demonstrating the feasibility of Fc-PMo 6 W 6 /RGO nanocomposite in routine testing xanthine to some extent.
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Environmental Science-Nano
·
2018
·Vol. 6
·期 1
·207-215
·
IF 6.087
Miao Peng,Guijian Guan,Hong Deng,Bin Han,Chen Tian,Junyang Zhuang,Yunyun Xu,Weizhen Liu,Zhang Lin
Considering p-arsanilic acid (p-ASA) as an organoarsenic pollutant, monitoring concentration of p-ASA is significant to maintain environmental security. Photoelectrochemical (PEC) detection is promisingly applied in environmental monitoring for its lower cost and simpler operation, compared to traditional techniques. However, general electrode materials of PEC sensors need to be modified with biological probes due to lack of specific binding sites to analytes, which may lead to complicated sensor fabrication and bio-recognizers inactivation during storage. Herein, a porphyrinic metal–organic framework/reduced graphene oxide (PCN-224/rGO) nanocomposite with simultaneously excellent photoelectric activity and strong binding characteristics was prepared and used to fabricate a PEC sensor for p-ASA detection avoiding the modification of bio-recognizers. Benefiting from the high conductivity of rGO, the separation efficiency of charge carriers was improved in PCN-224/rGO and thereby photocurrent gained an amplification of about 12 times. The PCN-224/rGO nanocomposite had strong affinity to p-ASA via Zr–O–As coordination and π–π stacking. Significantly, the binding of p-ASA could adjust the band position of PCN-224/rGO and facilitate oxygen reduction by releasing more photogenerated electrons, achieving photocurrent enhancement. The developed PEC sensor had a wide detection range, from 10 ng L−1 to 10 mg L−1, with a detection limit of 5.47 ng L−1. Furthermore, the sensor was successfully applied to monitor p-ASA in simulated natural water and swine manure lixivium. This study paved the way for the design of more efficient PEC sensors for environmental monitoring.
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MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 10
·1-10
·
IF 5.705
Huang Yan-Qin,Yang Li-Na,Wang Yong-Sheng,Xue Jin-Hua,Chen Si-Han
The authors report on a one-pot approach for synthesizing highly fluorescent protamine-stabilized gold nanoclusters. These are shown to be a viable nanoprobe for selective and sensitive fluorometric determination of lead(II) via quenching of fluorescence via Pb(II)-Au(I) interaction. Under optimized conditions, fluorescence measured at excitation/emission peaks of 300/599 nm drops in the 80 nM–15 μM lead(II) concentration range. The detection limit is 24 nM, and relative standard deviations (for n = 11) at concentrations of 0.10, 4.0 and 15 μM are 1.6, 2.5 and 1.9%, respectively. The relative recoveries of added lead(II) in the water samples ranged from 97.9 ± 2.29% to 101.2 ± 1.83%.
Lead(II) ions are found to be able to selectively and sensitively quench the fluorescence of the protamine-gold nanoclusters (PRT-AuNCs). Thereby, an inexpensive, selective and sensitive lead(II) assay was established.
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Journal of Sulfur Chemistry
·
2018
·
IF 1.32
Yanmei Chen,Xuefang Shang,Xing Zhao,Jie Li,Jianmei Yuan,Hongli Chen,Jinlian Zhang,Tianyun Wang
Two probes based on novel Copper(II) complexes were developed in order to obtain H2S molecular probes with higher selectivity. The molecular structures of the complexes were characterized by 1H NMR, HRMS, IR and elemental analysis. The interaction of the compounds with biologically important anions and amino acids was determined by UV-vis and Fluorescence titration experiments. Results indicated that the compounds showed the highest binding ability for HS− among studied anions (AcO−, H2PO4−, F−, Cl−, Br− and I−) and amino acids (GSH, HCys and Cys) accompanied by blue shift phenomenon in pure DMSO and aqueous solution. The possible mechanism of host–guest interaction may be that the Copper(II) ion of complex was captured by HS− and free ligand released which showed a remarkable changes in UV-vis absorption. In addition, cytotoxicity of the synthesized compounds was studied on MCF-7 cells. Results indicated that the synthesized compounds had low cytotoxicity over a concentration range of 0–150 µg⋅mL−1, which exhibited that the synthesized probes could be used to detect H2S in vivo.The probes based on novel copper(II) complexes were synthesized and obtained by the reaction of substituent salicylaldehyde with amine derivatives, and then reacted with Cu(CH3COO)2·H2O, respectively. Investigation on the interference from other species suggested that copper(II) complexes have high selectivity for HS− over other anions (AcO−, , F−, Cl−, Br− and I−), followed by the release of the copper ion to give a remarkable increase in UV–VIS absorption in pure DMSO solution and aqueous solution.
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AMERICAN JOURNAL OF CHINESE MEDICINE
·
2018
·Vol. 46
·期 03
·585-599
·
IF 3.12
Tianqiao Yong,Shaodan Chen,Yizhen Xie,Diling Chen,Jiyan Su,Ou Shuai,Huiping Hu,Dan Zuo,Danling Liang
Ethanol and water extracts of Armillaria mellea were prepared by directly soaking A. mellea in ethanol (AME) at 65 ∘ C, followed by decocting the remains in water (AMW) at 85 ∘ C. Significantly, AME and AMW at 30, 60 and 120 mg/kg exhibited excellent hypouricemic actions, causing remarkable declines from hyperuricemic control (351 μ mol/L, P < 0 . 0 1 ) to 136, 130 and 115 μ mol/L and 250, 188 and 152 μ mol/L in serum uric acid, correspondingly. In contrast to the evident renal toxicity of allopurinol, these preparations showed little impacts. Moreover, they showed some inhibitory effect on XOD (xanthine oxidase) activity. Compared with hyperuricemic control, protein expressions of OAT1 (organic anion transporter 1) were significantly elevated in AME- and AMW-treated mice. The levels of GLUT9 (glucose transporter 9) expression were significantly decreased by AMW. CNT2 (concentrative nucleoside transporter 2), a key target for purine absorption in gastrointestinal tract was involved in this study, and was verified for its innovative role. Both AME and AMW down-regulated CNT2 proteins in the gastrointestinal tract in hyperuricemic mice. As they exhibited considerable inhibitory effects on XOD, we selected XOD as the target for virtual screening by using molecular docking, and four compounds were hit with high ranks. From the analysis, we concluded that hydrogen bond, Pi–Pi and Pi-sigma interactions might play important roles for their orientations and locations in XOD inhibition.
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JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 4
·3144-3155
·
IF 2.993
Qu Fei,Li Xiaonan,Lv Xiaoxia,You Jinmao,Han Wenli
Photoinduced electron transfer (PET) has been used as reporter in the field of photoluminescence sensors and switches, and intermolecular PET is believed to be responsible for fluorescence quenching. Herein, the emissions of Tb-MOF can be quenched effectively by protamine based on PET. Compared with conventional electrostatic attraction mechanism, this approach suffers less interference from other charged substances and has a broader linear range of protamine from 3 to 5000 ng/mL with limit of detection (LOD) 1.21 ng/mL. Subsequently, the strong binding effect of protamine toward Hep ascribed to electrostatic attraction hinders the interaction between Tb-MOF and protamine, resulting in the high emissions of framework. The detection of Hep also shows a good linear range from 0.5 to 5 μM with LOD 0.27 μM. Finally, this novel probe is also successfully applied to the determination of protamine and Hep in human serum with satisfactory results.
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FOOD CHEMISTRY
·
2019
·
IF 5.399
Yukun Song,Yanyang Wu,Haitao Wang,Shan Liu,Liang Song,Shen Li,Mingqian Tan
The endogenous carbon quantum dots (CQDs) produced during food processing have potential uncertainty to human health. The objective of this study was to investigate the formation, biodistribution and cytotoxicity of CQDs in roasted Atlantic salmon ( Salmo salar Linnaeus ). The X-ray photoelectron spectroscopy (XPS) analysis showed that the CQDs were mainly composed of carbon, oxygen and nitrogen. The morphology, functional groups and optical properties were highly dependent on the roasting time. In vivo experiments in mice demonstrated that the CQDs distributed in the digestive tract, kidney, liver, and even brain, which indicated that they could cross the blood–brain barrier. The cell imaging results indicated that the CQDs could readily gain access to the normal rat kidney (NRK) cells, and caused autophagosome formation. The proportion of live cells decreased to 34.62% at 6 mg mL −1 of CQDs, and the energy generation route was changed from aerobic to glycolytic metabolism.
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Biointerphases
·
2018
·Vol. 13
·期 6
·
IF 2.455
Cheng Fang,Li Mingyang,Zhao Xuguang,Wang Hanqi,He Wei,Hua Xin,Wang Qing,Qu Jingping
Traditional strategies for the functionalization of materials displaying hydroxyl groups either require active esterification reagents or involve the nucleophilic attack of the hydroxyl group toward electrophilic groups. The former tends to hydrolyze in aqueous solutions while the latter occurs under harsh conditions. Herein, the authors reported a new method for the functionalization of hydroxyl groups on the surface via catalytic oxa-Michael addition with vinyl sulfones. Using hydroxyl group terminated self-assembled monolayers as a model surface, a series of organocatalysts were screened and triphenylphosphine stood out for the best catalytic activity. The catalytic reaction on the surface was characterized by x-ray photoelectron spectroscopy. The information of reaction kinetics was obtained using static water contact angle measurements. Once conjugated with ligands onto the functionalized surfaces, the multivalence binding of proteins was investigated by quartz crystal microbalance experiments. By varying the reaction conditions, e.g., catalyst types and reaction times, ligands can be anchored with a controllable density, which would be helpful to establish the relationships between ligand density and bioactivity.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Yamin Xiong,Lihong Zhou,Hui Wang,Huiling Li,Yue Hu,Peijun Meng,Xueying Zhang,Peili Huang
Monitoring the level of exchangeable copper (CuEXC) and ceruloplasmin (Cp) in serum is of great significance for Wilson’s disease (WD). In this work, a facile one-step competitive immunoassay for rapid and simultaneous detection of CuEXC and Cp has been developed based on antigens coated magnetic nanoparticles (immuno-MNPs) and antibodies functionalized quantum dots (QDs-Abs). Just by mixing immuno-MNPs, with diluted serum and QDs-Abs together, the antigens on immuno-MNPs compete with the target in serum and bind to QDs-Abs, thereby causing the changes in fluorescence intensity of QDs. Under selected conditions, this one-step method exhibited excellent precision and selectivity with the measured limit of detection of 0.2 nM and 7.0 μg/L for CuEXC and Cp, respectively. Most importantly, this method was successfully applied to detect CuEXC and Cp without the usual time-consuming pretreatment. The results showed no significant difference ( P >0.01) from those of ICP-AES and ELISA; moreover, CuEXC significantly decreased to a normal level after the treatment of preliminarily diagnosed WD patients, while the changes of Cp level is not significant ( P > 0.01). Therefore, the proposed one-step competitive immunoassay has great potential applications in the rapid laboratory diagnosis of WD with distinct advantages over the existing methods in terms of multi-target, accuracy, facile, fast and cost-effectiveness.
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