SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Chunlei Yang,Xiu Wang,Haiyun Liu,Shenguang Ge,Mei Yan,Jinghua Yu,Xianrang Song
A fluorescent sensor for the determination of glutathione (GSH) has been developed, which is based on the absorption of a newly designed thiols-specific chromogenic probe (CP) coupled with the use of a thiols-independent fluorophore g-C 3 N 4 nanosheets. It was operated on the inner filter effect (IFE). To construct an efficient IFE system, the CP molecules were adsorbed on the surface of g-C 3 N 4 nanosheets via π–π stacking interaction. When the biothiol introduced the systems, the weak fluorescence would be restored because of “IFE off”. The novel IFE sensor was established for GSH and regarded it as a model target analyte. The IFE sensor had a sensitive response for GSH in a linear range of 0.05 μM L −1 to 1.0 μM L −1 and the limit of detection was 0.01 μM. The sensor was successfully applied for the quantitative detection of biothiols in human serum. Additionally, the proposed sensor shows high specificity and sensitivity.
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高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Xinyu Hu,Yongmei Wang,Liangliang Zhang,Man Xu,Wei Dong,Jianfa Zhang
Salecan is a novel water-soluble extracellular β-glucan and possesses excellent physicochemical and biological properties. Here, redox/pH dual stimuli-responsive hydrogel based on Salecan grafted with itaconic acid (IA) and 2-hydroxyethyl methacrylate (HEMA) were prepared using disulfide-functionalized crosslinker N,N - bis (acryloyl)cystamine (BAC) for controlled drug delivery. The introduction of carboxylic groups endows the system with pH-sensitive character, swelling behavior of the hydrogel was conducted by changing the pH and Salecan content. It was demonstrated that DOX was efficiently loaded into the hydrogels and released in a controlled fashion via pH-control and swelling-shrinking mechanism. More importantly, DOX-loaded hydrogels showed dose dependent cytotoxicity toward A549 cell, and efficient cell killing was observed. Furthermore, a key point of this study was that the presence of disulfide linkage in system favored the degradation of hydrogels in the reductive environment. These results highlight the potential of Salecan- g -SS-poly(IA- co -HEMA) hydrogel as a novel system for the controlled release of anti-cancer drugs.
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PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2016
·
IF 8.328
Jianqing Ma,Qunfeng Yang,Yuezhong Wen,Weiping Liu
Heterogeneous Fe-N complexes are a kind of promising catalysts for the Fenton-like reaction. The present study selected a stable and inexpensive g-C 3 N 4 as the chelating agent and combined with the graphitized mesoporous carbon (GMC). The fabricated Fe-g-C 3 N 4 /GMC composite was characterized by several techniques including FTIR, XRD, XPS, TEM and STXM. Results showed clear sheets of g-C 3 N 4 and graphite with Fe evenly distributed mostly in the Fe-N coordination form. The catalyst expressed high activity in the Fenton-like reaction in a wide pH range of 4–10. 99.2% removal of Acid Red 73 was obtained in 40 min, and the degradation data well fitted with the pseudo-first-order kinetics model. By correlating the constant of reaction rates calculated from the model and the Fe speciation contents of the samples prepared at different conditions, we deduced that Fe-N species are the most important active sites for the Fenton-like reaction. More importantly, hydroxyl radicals played a great role in the whole reaction yet their generation was independent of visible light. Cyclic voltammetry results confirmed that the GMC can accelerate the Fe(III)/Fe(II) redox cycle by enhancing electron transfer, and thus enable this Fenton-like catalyst to perform well in a wide pH range.
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RSC Advances
·
2015
·Vol. 5
·期 51
·40726-40736
·
IF 3.84
Zhi Zhu,Ziyang Lu,Xiaoxu Zhao,Yongsheng Yan,Weidong Shi,Dandan Wang,Lili Yang,Xue Lin,Zhoufa Hua,Yang Liu
In the present work, based on Fe3O4/g-C3N4 as the support, 2-mercaptobenzothiazole (MBT) as the template molecule, and pyrrole as the functional monomer, we synthesized magnetic conductive imprinted photocatalysts (MCIPs) that were significantly efficient and stable through a suspension polymerization method. Moreover, the MCIPs not only exhibited a higher photodegradation capacity for MBT under visible light irradiation, but also possessed good selectivity. The specific surface areas of the resultant MCIPs were approximately four times that of pure g-C3N4. Furthermore, the results indicated that h+ was the major reactive species in the photocatalytic reaction system. The photodegradation mechanism was also discussed by analyzing the mass spectrum (MS), and the results demonstrated that MBT was degraded to H2O, CO2 and other small molecules, step by step. In addition, after five cycles, the MCIPs still showed high photocatalytic efficiency, indicating that the as-prepared MCIPs had excellent photochemical stability and good prospects for application in water treatment.
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APPLIED SURFACE SCIENCE
·
2014
·
IF 2.538
Chunhua Gu,Huan Zhang,Meidong Lang
Amphiphilic chitosan- graft -poly(ɛ-caprolactone) (CS- g -PCLs) copolymers were synthesized by a homogeneous coupling method and characterized by 1 H NMR, FTIR and ninhydrin assay. The graft copolymers were subsequently self-assembled into micelles, which were measured by DLS and TEM. The particle size of the micelles decreased as the segment grafting fraction was increased. Thereafter, silver nanoparticles were prepared in the presence of chitosan-based micelles under UV irradiation. The molar ratio and radiation time of silver to micelles were optimized with process monitored via UV–vis spectrophotometer. DLS and TEM were used to illustrate the particle structure and size while XRD patterns were applied to characterize the crystal structures of polymer-assisted silver nanoparticles. Films impregnated with silver nanoparticles were conducted with results of strong antimicrobial activities against Escherichia coli and Staphylococcus aureus as model Gram-negative and positive bacteria.
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RSC Advances
·
2015
·Vol. 5
·期 115
·94582-94590
·
IF 3.84
Keyong Liu,Pengju Pan,Yongzhong Bao
A series of poly(vinyl chloride)-g-poly(N-isopropylacrylamide) (PVC-g-PNIPAM) amphiphilic copolymers with different graft lengths and densities were synthesized via the single electron transfer-living radical polymerization (SET-LRP) of NIPAM using poly(vinyl chloride-co-allyl α-bromoisobutyrate) as macroinitiator. The living nature of SET-LRP grafting copolymerization was verified by the kinetics study and narrow molecular weight distribution of PNIPAM grafts. The chemical structure, micellisation, and thermally-induced multistep aggregation of PVC-g-PNIPAMs were investigated. PVC-g-PNIPAMs form micelles comprised of a PVC core and PNIPAM corona in water at room temperature. These micelles are thermoresponsive and show a lower critical solution temperature (LCST). The micelle size and LCST of PVC-g-PNIPAM increase with increasing the graft density and length of PNIPAM. PVC-g-PNIPAM exhibits a very unique aggregation behavior above its LCST and forms a three-dimensional macroscopic aggregate with a well-defined and tunable shape at an extremely low concentration (∼0.1 wt%). The aggregate shrinks to a more compact structure with the further increase of temperature. Higher copolymer concentration, longer graft length, and lower graft density are favorable for the macroscopic micelle aggregation of PVC-g-PNIPAMs. A self-standing and superporous PVC-g-PNIPAM material having an extremely low density of ∼0.01 g cm−3 and a high porosity of >99% is attained after freeze-drying the micelle aggregate.
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JOURNAL OF MATERIALS RESEARCH
·
2014
·Vol. 29
·期 18
·2170-2178
·
IF 1.815
Xiaomeng Lü,Jiayu Shen,Ziwei Wu,Jiaxi Wang,Jimin Xie
Plasmonic Ag nanoparticles (AgNPs) with narrow distribution were successfully loaded on graphitic carbon nitride (g-C3N4) sheet by thermal polymerization of melamine precursor and a simple wet-chemical pathway in the presence of polyvinylpyrrolidone (PVP). N,N-dimethylformamide (DMF) was used as an efficient reducing agent as well as a solvent and its presence facilitated homogeneous distribution of AgNPs under mild reaction condition and easy control of its particle growth under different precursor amounts. Ag/g-C3N4 composites of different Ag content were prepared, and the phase, chemical structure, morphologies, electronic and optical properties of Ag/g-C3N4 heterostructures were well characterized, respectively. The photocatalytic activity of Ag/g-C3N4 composites was evaluated by the decolorization of methyl orange (MO), and they exhibited superior photocatalytic activity to bulk g-C3N4 under visible-light irradiation. Influence of Ag content to photocatalytic activity was also discussed and possible mechanism was explored based on the analysis of photoluminescence spectra (PL) and photodecoloration activity.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2014
·
IF 3.84
Zi-Ming Zhou,Yong Yu,Ming-Zhen Zhang,Jun Chen,Qiong-Qiong Ren,Ji-Tao Song,Bo Liu,Zhi-Ya Ma,Yuan-Di Zhao
It is important to design new ways with high specificity and sensitivity to detect lead (II). Here, ‘8–17’ DNAzyme was used as a Pb 2+ -dependent probe with high sensibility and selectivity based on chemiluminescence (CL). When Pb 2+ was present, the substrate strand was cleaved and the active hemin/G-quadruplex DNAzyme structure was formed in the presence of another sequence which contained two parts, one could be complementary with part of the substrate strand and the other was a G rich subunit. The active hemin/G-quadruplex DNAzyme structure could catalyze luminol oxidation and quantitative analysis of Pb 2+ was carried out according to the CL of luminol. Results showed that CL intensity of luminol at 452 nm had a linear relation with the concentration of Pb 2+ in the range from 5 nM to 1 μM, and the limit of detection was 0.79 nM ( S / N = 3). This method was also used to detect the contents of Pb 2+ in lake water and tobacco and the results (62.4 ± 4.0 nM and 15.2 ± 2.2 nM, respectively) were extremely closed to those of inductively coupled plasma-mass spectrometry (ICP-MS) (57.0 ± 1.4 nM and 14.5 ± 0.91 nM, respectively).
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ANALYTICAL CHEMISTRY
·
2013
·
IF 5.695
Chun Yang,Lei Liu,Tao Zeng,Daowu Yang,Zhiyi Yao,Yuliang Zhao,Hai-Chen Wu
Both Pb2+ and Ba2+ can bind with high affinity to some specific DNA sequences, inducing the formation of unimolecular G-quadruplex structures. Translocation of a DNA probe containing such sequences through an α-hemolysin nanopore in the presence of Pb2+ or Ba2+ would result in much prolonged DNA translocation events. Quantification of these events can reveal the concentrations of Pb2+ or Ba2+ at as low as 0.8 nM. Besides, Pb2+ and Ba2+ in the solution can be simultaneously detected and individually identified. Furthermore, the probe is highly selective for Pb2+ and Ba2+ detection without interference from other metal ions. This sensing strategy can be extended to many other analytes which can bind to DNA molecules with high affinity.
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JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 51
·期 2
·893-902
·
IF 2.371
Wang Desong,Xu Zexuan,Luo Qingzhi,Li Xueyan,An Jing,Yin Rong,Bao Cai
An efficient visible-light photocatalyst was successfully synthesized by surface-hybridizing graphitic carbon nitride (g-C 3 N 4 ) using a small amount of cadmium sulfide (CdS) nanoparticles. The CdS/g-C 3 N 4 nanocomposites were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, UV–Vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, electrochemical impedance spectroscopy, and photocurrent–time measurement. The photocatalytic activity of the CdS/g-C 3 N 4 nanocomposites was investigated by evaluating the degradation of Rhodamine B (RhB) under visible-light irradiation. The effects of the CdS content on the nanocomposites, initial RhB concentration, pH value of the investigated system, and dosage of CdS/g-C 3 N 4 nanocomposites on the visible-light photocatalytic activity were systematically investigated. The results revealed that the visible-light photocatalytic activity of g-C 3 N 4 -based photocatalysts was significantly improved by surface-hybridization of a small amount of CdS nanoparticles, increased as both CdS content on the nanocomposites and dosage of CdS/g-C 3 N 4 nanocomposites increased, while increased at first and then decreased as both initial RhB concentration and pH value of the investigated system increased. The visible-light photocatalytic mechanism of the CdS/g-C 3 N 4 nanocomposites was discussed.
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RESEARCH ON CHEMICAL INTERMEDIATES
·
2015
·Vol. 42
·期 2
·481-497
·
IF 1.221
Wang Chenxi,Wan Jinquan,Ma Yongwen,Wang Yan
The degradation of Orange G (OG) by persulfate (PS, S 2 O 8
2− ) activated with dual catalysts that combined zero-valent iron (ZVI) and copper oxide (CuO) was investigated through batch experiments. Effects of pH, initial OG concentration, persulfate dosages, and dosages of dual catalysts on OG degradation were also examined. Higher persulfate concentration and catalysts dosages resulted in higher OG degrading rates. The OG degradation was higher under acidic conditions (pH 3.0 and 5.0) when compared to alkaline conditions. The constituents and the morphology of the catalysts coating before and after reaction were also investigated with X-ray diffraction and scanning electron microscopy. Radical mechanism was studied and three radical scavengers [methanol (MA), tert-butanol (TBA), phenol] were used to determine the type of major active species taking part in the degradation of OG. It was assumed that the \({\text{SO}}_{4}^{ \cdot - }\) or \({\text{HO}} \cdot\) played a major role in the OG degradation. In conclusion, the ZVI/CuO/PS system is a good candidate for use in detoxifying water contaminants.
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TALANTA
·
2013
·
IF 3.498
Yuezhen He,Xiaoxun Wang,Yuzhong Zhang,Feng Gao,Yongxin Li,Hongqi Chen,Lun Wang
In this work, we reported a sensitive chemiluminescent immunosensor for the detection of human leptin by using hemin/G-quadruplex DNAzymes to amplify detection signal. In this sensing system, the primary antibody (anti-human leptin) was firstly bound to the 96-well plates, and human leptin and biotinylated secondary antibody were successively combined to form sandwich-type immune complex through specific interactions. Then streptavidin labeled with hemin/G-quadruplex DNAzymes was assembled to the sandwich-type immunocomplex by streptavidin–biotin interaction. The DNAzymes exhibited an excellent catalytic activity to the chemiluminescent reaction of luminol with hydrogen peroxide in strong alkaline solution, leading to significant enhancement in response signal. Under the optimum conditions, the proposed immunosensor showed high sensitivity and selectivity with a low detection limit of 1.9 pg mL −1 and a wide linear response range of human leptin from 10 to 1000 pg mL −1 . The immunosensor was used to detect human leptin in serum, and the results were in good agreement with the data obtained by conventional ELISA method.
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PubMed
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