APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2014
·Vol. 173
·期 8
·2005-2018
·
IF 1.687
Yao Huiqin,Lin Ling,Wang Peng,Liu Hongyun
Dual-responsive poly( N , N -diethylacrylamide) (PDEA) hydrogel films with entrapped horseradish peroxidase (HRP) and glucose oxidase (GOD) were successfully prepared on electrode surface with a simple one-step polymerization procedure under mild conditions, designated as PDEA-HRP-GOD. Cyclic voltammetric (CV) response of electroactive probe K 3 Fe(CN) 6 at the film electrodes displayed reversible thermo- and sulfate-responsive switching behavior. For example, at 25 °C, the K 3 Fe(CN) 6 demonstrated a well-defined CV peak pair with large peak currents for the films, showing the on state, while at 40 °C, the CV response was greatly suppressed and the system was at the off state. The influence of temperature and Na 2 SO 4 concentration on the switching behavior of the film system was not independent or separated, but was synergetic. The responsive mechanism of the system was ascribed to the structure change of PDEA component in the films with temperature and sulfate concentration. This switching property of the PDEA-HRP-GOD films could be further used to realize dual-responsive catalytic oxidation of glucose sequentially by HRP and GOD entrapped in the films with Fe(CN) 6
3− as the mediator through changing the surrounding temperature and Na 2 SO 4 concentration. This system may establish a foundation for fabricating a new type of multi-switchable electrochemical biosensors based on bienzyme electrocatalysis.
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高影响因子
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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高影响因子
Plasmonics
·
2015
·Vol. 11
·期 3
·771-779
·
IF 2.238
Zhang Pengfei,Liu Le,He Yonghong,Ji Yanhong,Guo Jun,Ma Hui
We describe a temperature-regulated surface plasmon resonance (SPR) imaging biosensor in this article. The sample temperature can be regulated for specific requirements of the bioaffinity sensing, and stabilized to suppress the measurement noise caused by temperature fluctuations. The water thermo optic coefficient is measured to test the temperature regulation performance. The protein interaction is monitored to demonstrate the feasibility of this system for real-time biomolecular interaction analysis. This temperature-regulated SPR imaging biosensor can be readily implemented by adding the common water path and peristaltic pump to the conventional SPR imaging system, which may provide an economical and convenient scheme to improve the analysis accuracy and quality of bioaffinity sensing using SPR sensing platform.
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高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2015
·Vol. 46
·期 1
·1-8
·
IF 2.409
Liang Xiaocai,Xiao Mingshu,Xu Minglu,Yang Dazhang,Yan Yuhua,Tian Yanping,Miao Yuqing
This study investigated the simultaneous in situ formation of Ni-based catalysts at the anode and cathode for glycerol oxidation and hydrogen evolution, respectively. The formation of electrocatalysts and their immobilization on the electrode surface occur simultaneously, avoiding the tedious and laborious procedures for the preparation and immobilization of the electrocatalysts. Ni salt in the homogeneous solution was deposited to repair the Ni-based electrocatalysts on the electrode surface, accompanied by the electrolysis of glycerol at the anode and the hydrogen evolution reaction at the cathode, exhibiting good working stability. This technique may find potential applications in the conversion of solar energy into storable fuels via the electrolysis of H 2 O or small molecules to produce hydrogen.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2015
·Vol. 17
·期 4
·1-11
·
IF 2.184
Zeng Xianghua,Yan Shunjun,Cui Jieya,Liu Hongfei,Dong Jing,Xia Weiwei,Zhou Min,Chen Haitao
Typical morphology substrates can improve the efficiency
of surface-enhanced Raman scattering; the need for SERS substrates of controlled morphology requires an extensive study. In this paper, one-dimensional ZnS:Al nanostructures with the width of approximately 300 nm and the length of
tens um, and micro-scale structures with the width of several um and the length of tens um were synthesized via thermal evaporation on Au-coated silicon substrates and were used to study their size effects on Raman scattering and photoluminescent spectra. The photoluminescence spectra reveal the strongest green emission at a 5 at% Al source, which originates from the Al-dopant emission. The Raman spectra reveal that the size and morphology of the ZnS:Al nanowires greatly influences the Raman scattering, whereas the Al-dopant concentration has a lesser effect on the Raman scattering. The observed Raman scattering intensity of the saw-like ZnS:Al nanowires with the width of tens nm was eight times larger than that of the bulk sample. The enhanced Raman scattering can be regarded as multiple scattering and weak exciton—phonon coupling. The branched one-dimensional nanostructure can be used as an ideal substrate to enhance Raman scattering.
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高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2015
·Vol. 33
·期 6
·857-868
·
IF 1.835
Du Chun-hui,Ma Xu-min,Wu Chun-jin,Cai Mei-qiang,Hu Meng-xin,Wang Ting
Polymerizable ionic liquid copolymer P(MMA- co -BVIm-Br) was synthesized by radical polymerization technique, and characterized by Fourier transform infrared spectrometry (FTIR), 1 H Nuclear magnetic resonance ( 1 H-NMR) and gel permeation chromatography (GPC). The resulting copolymer was used to prepare poly(vinylidene fluoride) (PVDF) blend membranes via a phase inversion method. The effects of the copolymer on the polymorphism, surface wettability and zeta potential ( ζ ) of the blend membranes were investigated by ATR-FTIR, contact angle instrument and zeta potential analyzer. Scanning electron microscopy (SEM and SEM-EDS) was also applied to investigate the morphology and the surface element changes of the fabricated membranes. The results indicated that P(MMA- co -BVIm-Br) copolymer existed on the surface of the membrane which made the blend membrane have a positive surface during the experimental pH range. The copolymer was also in favor of the formation of β crystal phase in PVDF membranes. The contact angle experiment indicated that P(MMA- co -BVIm-Br) copolymer could switch the wettability of the blend membranes from hydrophilic to hydrophobic by exchanging Br − anion with PF 6
− . Compared with pure PVDF membranes, the water flux and water recovery flux of the blend membranes were enhanced obviously. The results from the flux recovery ratio (FR) and total fouling ratio ( R
t ) all suggested that the blend membranes had good anti-fouling properties.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2014
·Vol. 50
·期 5
·2239-2246
·
IF 2.305
Hu Lei,Cheng Xinjian,Zhang Aiqing
It is of importance to prepare self-healing materials using reversible covalent bonding within polymers. In this work, we introduced ethyl 4-aminocinnamate (EA) to polyphosphazenes to prepare a novel self-healing elastomer via the reversible photochemical [2+2] cycloaddition. Linear polymer, poly[( n -butylamino)
x
(ethyl 4-aminocinnamate)
y
] phosphazene, was synthesized firstly via the ring-opening polymerization, and then substitution reaction was conducted to introduce EA as side groups. Consequently, the damaged polyphosphazenes were re-healed by being exposed to UV light. Their structures were characterized by 1 H-NMR, 31 P-NMR, FTIR, and GPC; thermal properties were tested by TGA and DMA. The [2+2] cycloaddition reaction and retro-[2+2] cycloaddition were investigated by UV–vis. The results showed that the broken polyphosphazenes could be self-healed by the UV light irradiation at 365 nm. The damaged polyphasphozene could be re-healed almost completely within about half an hour.
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MICROCHIMICA ACTA
·
2014
·Vol. 181
·期 11
·1407-1413
·
IF 3.719
Liu Cunwei,Li Baoxin,Xu Chunli
We report on a method for visual differentiation between the D- and L-forms of tryptophan (Trp). It is based on the inherent chirality of citrate-capped silver nanoparticles (AgNPs; ca. 15 nm in diameter) that can be used as chiral selector for D- and L-forms of Trp. On addition of D-Trp to a solution of the AgNPs, a color change from yellow to red can be seen, while no color change is found on addition of L-Trp. The chiral assay can be used to determine the enantiometric excess of D-Trp in the range from −50 % to 100 %. The effect can be detected with bare eyes and quantified by spectrophotometry. Notably, this method does not require any labeling or chiral modification. The method excels by its sensitivity, low cost, good availability of materials, and its simplicity.
The silver nanoparticles can discriminate the absolute configuration of Trp and determine the enantiomeric excess of Trp
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高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2014
·Vol. 38
·期 5
·833-839
·
IF 1.823
Liu Zhenfeng,Shen Yanmin,Li Weiwei,Zhang Wen,Li Tao,Ren Baozeng
The synthesis of d -isoascorbyl stearate from d -isoascorbic acid and stearic acid with immobilized lipase (Novozym ® 435) as catalyst was studied. Response surface methodology and Box-Behnken design with six variables and three levels were employed to evaluate the effects of processing conditions on the conversion of d -isoascorbic acid. The results confirmed that the response surface method and statistical analysis were proved to be useful in developing optimal conditions for d -isoascorbyl stearate synthesis. The optimum conditions were predicted as follows: reaction temperature 48 °C, reaction time 17.7 h, immobilized lipase amount 50.0 % (w/w, of d -isoascorbic acid), substrate molar ratio 9:1 (stearic acid to d -isoascorbic acid), d -isoascorbic acid concentration 0.14 mol/L (based on solvent), 4A molecular sieve addition 200 g/L (based on solvent), and the optimal conversion was 90.6 %. Through the kinetics model fitting of the esterification, it was considered that the esterification conformed to a Ping–Pong bi–bi kinetic model with d -isoascorbic acid inhibition, and the obtained kinetic constants showed that the inhibition of d -isoascorbic acid and the enzyme affinity to substrate were abate with the increase of the reaction temperature.
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高影响因子
MICROCHIMICA ACTA
·
2014
·Vol. 182
·期 3
·855-862
·
IF 3.719
Yan Fufeng,Zhang Yuanchang,Zhang Shuai,Zhao Jihong,Liu Shunli,He Linghao,Feng Xiaozhong,Zhang Hongzhong,Zhang Zhihong
We report on an efficient method for the production carboxy-modified graphene (carboxy-GR), and its application to a highly sensitive immunoassay for the livestock feed additive clenbuterol. Octadecanoic acid is shown to self-assemble on carboxy-GR via intermolecular interaction. Goat anti-mouse IgG was conjugated to 1-octadecanethiol-modified carboxy-GR and then deposited by self-assembly on a C18-modified gold surface. The resulting sensor surface was used to quantify clenbuterol by both surface plasmon resonance and electrochemical impedance spectroscopy. The assay works in the 0.01 ng∙mL −1 to 10 ng∙mL −1 concentration range and the lower detection limit is 6.57 pg∙mL −1 . It is concluded that this fairly simple method can be extended to immunoassays for other food additives.
Principle of sensor system and immunoassay. (i) Binding of ACG–IgG with the alkyl chain of 1-octadecanethiol through intermolecular force onto the gold substrate; (ii) absorbance of Ab CLB onto the surface of ACG-IgG; and (iii) detection of CLB using an immunoassay based on Ab CLB –ACG–IgG.
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高影响因子
JOURNAL OF POLYMER RESEARCH
·
2014
·Vol. 21
·期 11
·1-8
·
IF 1.897
Ran Xiaoqi,Yi Shixiong,Liang Liefeng,Yang Xiao
The effect of oxygen on photodegradation of π-conjugated aromatic poly(1,3,4-oxadiazole)s (POD) was studied in detail. The results obtained by tensile test, UV-spectra and ATR-FTIR revealed that the oxygen was indispensable during photodegradation of POD. The occurrence of photodegradation of POD must be combination of UV exposure and oxygen simultaneously. The state of oxygen during photodegradation of POD was investigated by nitrotetrazolium blue chloride (NBT) method. The result illustrated that the oxygen was transformed into superoxide anion radical through accepting one electron during UV exposure. Results of tensile tests and UV-spectra further proved that the superoxide anion radical could combine with excited POD to form an unstable product that lead to occurrence of photodegradation. Singlet oxygen was also investigated and the result showed that POD appeared to be stable to singlet oxygen.
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高影响因子
CELL BIOCHEMISTRY AND BIOPHYSICS
·
2014
·Vol. 71
·期 2
·535-541
·
IF 2.38
Lin Lin,Zheng Jing,Zhu Weiping,Jia Ning
Cisplatin-induced generation of reactive oxygen species leads to acute nephrotoxicity limiting its use in the treatment of various cancers. Gelsemine, an alkaloid isolated from Gelsemium elegans , is known to possess anti-inflammatory and anti-cancer activities. This study was aimed to investigate as to whether gelsemine can serve as a protective agent against cisplatin-induced nephrotoxicity. Male Wistar rats were divided into 6 groups, each with 6 rats. Group 1 served as control and received the vehicles (peanut oil for 14 days and 0.9 % saline on day 14 for gelsemine and cisplatin respectively). Group 2 received a single intraperitoneal injection of cisplatin on day 14. Group 3 and 4 were pretreated with two different doses of gelsemine in addition to cisplatin, and group 5 and 6 received only gelsemine. The effects of gelsemine on cisplatin-induced nephrotoxicity were examined by measuring anti-oxidant enzymes activities, lipid peroxidation, and DNA damage in the kidneys, a well-established model of oxidative damage. Pretreatment of rats with gelsemine caused a significant attenuation of cisplatin-induced DNA and oxidative damages. The blockade of lipid peroxidation and xanthine oxidase activity was accompanied by increased production and/or activity of anti-oxidants, both enzymatic (catalase, glutathione peroxidase, glutathione reductase, and glutathione- S -transferase) and non-enzymatic (GSH). The biomarkers of kidney malfunctioning, creatinine, and blood urea nitrogen were ameliorated. The results of the present study suggest that gelsemine effectively suppressed cisplatin-induced renal injury by improving redox status.
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高影响因子
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