BIOMEDICAL MICRODEVICES
·
2017
·Vol. 19
·期 2
·1-10
·
IF 2.062
Kang Yufeng,Zou Lili,Qiu Bensheng,Liang Xin,Sun Sijie,Gao Dayong,Ding Weiping
In this paper, a multistep dilution-filtration microdevice (MDFD) is developed for unloading cryoprotectants from cryoprotectant-loaded cells. The MDFD contained a diluent producing region, a dilution-filtration execution region, and a filtrate collection region. It was made of two patterned PMMA stamps with four pieces of sandwiched PVDF membranes. Firstly, the performances of the mixers that were used in the diluent producing region and the dilution-filtration execution region were assessed using fluorescence experiments. Then, the effect of the MDFD structure on the loss of cells was investigated by applying the MDFD to unload glycerin from glycerin-loaded porcine red blood cells. Finally, the effects of the cell density, glycerin concentration, and membrane pore size on the clearance efficiency of glycerin ( C
G
), the survival rate of cells ( S
C
) and the recovery rate of cells ( R
C
) have been studied. Under the designed conditions, C
G
achieved ~80% and S
C
reached ~90%. However, R
C
was only ~40%, mainly resulting from the cells detained on the membrane surface and squeezed through the membrane pores into the filtrate. Increasing the membrane pore size caused high C
G
and S
C
, but low R
C
. For a low glycerin concentration, C
G
, S
C
, and R
C
were all high. For a high cell density, C
G
was high, but both S
C
and R
C
were low. This work is of significance to develop a microfluidic chip for unloading cryoprotectants from a small amount of cryopreserved cell samples.
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高影响因子
MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 5
·1353-1360
·
IF 4.58
Liu Qiao,Liu Xing-Pei,Wei Yu-Pin,Mao Chang-Jie,Niu He-Lin,Song Ji-Ming,Jin Bao-Kang,Zhang Sheng-Yi
CdSe:Eu nanocrystals were successfully synthesized and characterized by transmission electron microscopy, X-ray powder diffraction, and X-ray photoelectric spectroscopy. The CdSe:Eu nanocrystals showed enhanced green electrochemiluminescence (ECL) intensity when compared to pure CdSe nanocrystals. Further, the nanocrystals were used to design an ECL immunosensor for the detection of carcinoembryonic antigen (CEA) that has a linear response over the 1.0 fg·mL −1 to 100 ng·mL −1 CEA concentration range with a 0.4 fg·mL −1 detection limit. The assay was applied to the determination of CEA in human serum samples.
Schematic of the assay: GCE-glassy-carbon electrode, Ab- Antibody, BSA- Bovine serum albumin, Ag- Antigen. CdSe:Eu nanocrystals were used to design an ECL immunosensor for the detection of carcinoembryonic antigen.
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TRANSACTIONS OF TIANJIN UNIVERSITY
·
2017
·Vol. 24
·期 1
·16-24
·
IF 0
Sun Jinsheng,Wei Dongmei,Lv Hao
This study focuses on shape-controlled synthesis of gold nanoparticles, using the green reducing agent l -Tryptophan ( l -Trp), which is non-toxic and eco-friendly. This specific agent was investigated to realize certain morphology controlling effects by changing the relative growth rates among various crystal planes. Experimental samples were characterized by transmission electron microscope, UV–Vis spectrophotometer and X-ray diffraction (XRD) for size and morphological information. The effects of the specific additives of PVP ((C 6 H 9 NO)
n
), CTAB (C 16 H 33 (CH 3 ) 3 NBr), and KBr were examined for their morphological control individually and synergistically in this system. Hexagonal gold nanoparticles were successfully obtained via the PVP/CTAB and PVP/KBr systems. Particular amounts of PVP/KBr produced various polyhedron structures, such as cubes, and others with triangular and rhombic straight-side cross sections.
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Science China-Chemistry
·
2017
·Vol. 61
·期 2
·164-171
·
IF 4.132
Huang Xueqiong,Kong Long,Huang Shouqiang,Liu Min,Li Liang
In this work, we report the synthesis of magnetic sulfur-doped Fe 3 O 4 nanoparticles (Fe 3 O 4 :S NPs) with a novel simple strategy, which includes low temperature multicomponent mixing and high temperature sintering. The prepared Fe 3 O 4 :S NPs exhibit a much better adsorption performance towards Pb(II) than bare Fe 3 O 4 nanoparticles. FTIR, XPS, and XRD analyses suggested that the removal mechanisms of Pb(II) by Fe 3 O 4 :S NPs were associated with the process of precipitation (formation of PbS), hydrolysis, and surface adsorption. The kinetic studies showed that the adsorption data were described well by a pseudo second-order kinetic model, and the adsorption isotherms could be presented by Freundlich isotherm model. Moreover, the adsorption was not significantly affected by the coexisting ions, and the adsorbent could be easily separated from water by an external magnetic field after Pb(II) adsorption. Thus, Fe 3 O 4 :S NPs are supposed to be a good adsorbents for Pb(II) ions in environmental remediation.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 22
·18640-18650
·
IF 2.741
Chen Yuan,Lei Xin,Dou Rongni,Chen Yuancai,Hu Yongyou,Zhang Zhiqi
A water-compatible magnetic triclosan (TCS) imprinted material (TCS-CTS-Fe 0 -MIPs) was synthesized for selective enrichment and detection of TCS in real complex water samples. The material was synthesized by using chitosan (CTS) as functional monomer, which has rich surface O- and N-containing functional groups. The TCS imprinted CTS was coated on Fe 0 surface and then cross-linked with glutaraldehyde. Scanning electron microscopy suggested that the imprinted material was covered with a layer of imprinted film, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirmed that the imprinted material had more functional groups (amino and hydroxyl groups) than that of non-imprinted material. The TCS imprinted and non-imprinted materials used in each adsorption experiments were 0.1 mg mL −1 . The maximum adsorption capacity of the TCS imprinted material and non-TCS imprinted material were 20.86 and 15.11 mg g −1 , respectively. The adsorption results showed that selectivity coefficient was 10.151, 1.353, and 8.271 in the presence of p-chlorophenol, 2,4,6-trichlorophenol, and bisphenol-A, respectively. The recoveries of river water and lake water samples were 92.8, 91.3, 92.4, and 81.4, 82.3, 82.1%, respectively, when the samples were spiked with 4, 6, and 8 μg L −1 of TCS with the imprinted material. The adsorption capacity of the TCS imprinted material and non-TCS imprinted material lost 5.2 and 6.2% after six times of recycling. The high selectivity and excellent adsorption capacity of the imprinted material can be attributed to the presence of sterically complementary imprinted sites and high surface, which would also made it more accessible to TCS than that of non-imprinted material. The present study would provide an environmental friendly and convenient method for the removal and the monitoring of TCS in environmental water samples.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 28
·期 9
·6544-6551
·
IF 2.019
Wu Guanglei,Li Junli,Wang Kuikui,Wang Yiqun,Pan Chen,Feng Ailing
In this paper, titanium dioxide (TiO 2 )/phenolphthalein-type polyimide (PPPI) composite was synthesized in situ polymerization, the diamino phenolphthalein type compound and dimethylacetamide as the matrix, and TiO 2 as the filler. The mechanical property and thermal conductivity properties were used to characterize the properties of the obtained composite. A diamine monomer containing more benzene rings of phenolphthalein and an ether bond in its main chain were prepared, synthesized by a nucleophilic substitution reaction and a hydrazine hydrate reduction reaction. Polyimide composite had the same structure as that of a diamine monomer. And it was synthesized by solution imidization and heat imidization. The results showed that TiO 2 improved the dispersibility, alignment and interfacial strength of the TiO 2 /PPPI composite. The mechanical property of polyimide composite was increased with the increasing TiO 2 loading. And a suitable addition of TiO 2 could enhance the mechanical properties of polyimide system. Compared to polyimide resin, the TiO 2 /PPPI composite had a higher thermal conductivity with the increasing of TiO 2 content. All of these changes in properties were closely correlated with the TiO 2 /PPPI composite, which could form an interaction interface structure in the system.
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MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 3
·907-914
·
IF 4.58
Yao Wensong,Wu Namei,Lin Zhen,Chen Jinyuan,Li Shaoguang,Weng Shaohuang,Zhang Lingling,Liu Ailin,Lin Xinhua
Blue fluorescent carbon dots (C-Dots) were synthesized by a hydrothermal process using citric acid and polyethylene-polyamines as the precursors. The C-dots display strong fluorescence, excellent water solubility, good biocompatibility, and possess many amino groups on their surface. Biotin was linked to the amino groups, and the resulting biotinylated C-dots were applied in a binding assay where they compete with free biotin (vitamin B7; coenzyme R) for binding to streptavidin immobilized on superparamagnetic Dynabeads®. After incubation and magnetic separation, the fluorescence intensity of immobilized biotinylated C-dots released from the beads is inversely proportional to the concentration of biotin in the 0.5 to 100 ng·mL −1 concentration range. The detection limit is 0.1 ng·mL −1 . Conceivably, the method may be further extended to the determination of biotinylated biomolecules.
One-pot hydrothermal synthesized C-Dots were biotinylated and used as fluorescent probe in the immunoassay for the determination of Vitamin B7.
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Food Analytical Methods
·
2017
·Vol. 10
·期 7
·2293-2301
·
IF 2.038
Qin Changchun,Guo Wenlu,Liu Yan,Liu Zhanchao,Qiu Jian,Peng Jianbo
In this study, a new imprinted electrochemical sensor for selectively detecting sunset yellow was developed based on glassy carbon electrode (GCE) modified by graphene oxide decorated with silver nanoparticles–molecular imprinted polymers (GO/AgNPs–MIPs). GO/AgNPs were firstly synthesized using self-assembly technology, and GO/AgNPs–MIPs were synthesized through surface imprinted technology by using GO/AgNPs as the substrate and sunset yellow as the template, respectively. The sensor was prepared by a drop-casting method. The synthetic materials were characterized by transmission electron microscope (TEM), Fourier transmission infrared spectra (FT-IR), and X-ray diffraction (XRD). The sensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The usage amount of GO/AgNPs–MIPs suspensions, solution pH, and accumulation time made an important difference in the process of detecting sunset yellow. Under optimal conditions, the peak current is linear to concentration of sunset yellow in the ranges of 0.1–0.6 and 0.6–12 μM, and the limit of detection was estimated to be 0.02 μM ( S / N = 3). Finally, the proposed sensor was applied to detect sunset yellow in soft drinks with acceptable recovery, which demonstrated that the sensor could be used as a reliable and simple method for practical detection of sunset yellow.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2016
·Vol. 408
·期 25
·6945-6956
·
IF 3.125
Kumar Saroj,Kumar Dileep,Ahirwar Rajesh,Nahar Pradip
Bioconjugation and functionalization of polymer surfaces are two major tasks in materials chemistry which are accomplished using a variety of coupling agents. Immobilization of biomolecules onto polymer surfaces and the construction of bioconjugates are essential requirements of many biochemical assays and chemical syntheses. Different linkers with a variety of functional groups are used for these purposes. Among them, the benzophenones, aryldiazirines, and arylazides represent the most commonly used photolinker to produce the desired chemical linkage upon their photo-irradiation. In this review, we describe the versatile applications of 4-fluoro-3-nitrophenyl azide, one of the oldest photolinkers used for photoaffinity labeling in the late 1960s. Surprisingly, this photolinker, historically known as 1-fluoro-2-nitro-4-azidobenzene (FNAB), has remained unexplored for a long time because of apprehension that FNAB forms ring-expanded dehydroazepine as a major product and hence cannot activate an inert polymer. The first evidence of photochemical activation of an inert surface by FNAB through nitrene insertion reaction was reported in 2001, and the FNAB-activated surface was found to conjugate a biomolecule without any catalyst, reagent, or modification. FNAB has distinct advantages over perfluorophenyl azide derivatives, which are contemporary nitrene-generating photolinkers, because of its simple, single-step preparation and ease of thermochemical and photochemical reactions with versatile polymers and biomolecules. Covering these aspects, the present review highlights the flexible chemistry of FNAB and its applications in the field of surface engineering, immobilization of biomolecules such as antibodies, enzymes, cells, carbohydrates, oligonucleotides, and DNA aptamers, and rapid diagnostics.
An overview of the FNAB-engineered activated polymer surfaces for covalent ligation of versatile biomolecules
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高影响因子
Nano Research
·
2016
·Vol. 9
·期 10
·3129-3140
·
IF 8.893
Li Mingming,Tang Minghui,Deng Jiang,Wang Yong
The development of novel, simple, and convenient techniques for the fabrication of porous carbon materials with desirable properties, such as tunable pore structures and the presence of nitrogen functionalities, from renewable and abundant biomasses is required. We herein describe an in situ directing method for the preparation of a nitrogen-doped flower-like porous carbon (NFPC) employing arbitrarily shaped MgO from bio-derived glucosamine chloride (GAH). Experimental evidence demonstrated that the structure directing effect of the Mg(OH) 2 nanosheets formed in situ from MgO hydrolysis was key to this process, with the original MgO morphology being irrelevant. Furthermore, this method was applicable for a wide variety of biomass-derived carbon precursors. The resulting NFPC exhibited a high nitrogen content of ≤9 wt.%, and was employed as a support to anchor small Ru nanoparticles (average size = 2.7 nm). The resulting Ru/NFPC was highly active in heterogeneous hydrogenations of toluene and benzoic acid, which demonstrated the advantages of nitrogen doping in terms of boosting catalytic performance.
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JOURNAL OF POLYMER RESEARCH
·
2017
·Vol. 24
·期 8
·1-7
·
IF 1.615
Gong Zhengyu,Niu Fangfang,Zhang Guoping,Li Jinhui,Li Gang,Huang Wangping,Deng Hai,Sun Rong,Wong Chingping
In previous work, we have developed a dual physically cross-linked hydrogel composed of poly (acrylamide-co-acrylic acid) (PAM-co-PAA) and polyvinyl alcohol (PVA), named as PVA/CP DN gel, by facile copolymerization and freezing/thawing. The PVA/CP DN gel is featuring both excellent mechanical properties and self-healing ability. Additionally, we have preliminarily found that the comonomer ratio for PVA/CP DN gel have great influence on the self-healing efficiency. In this research article, we will further discuss the mechanical and self-healing properties of the PVA/CP DN gel by varying the comonomer ratio of PAM-co-PAA. The results proved that the structure of DN will be loosen when the number of PAA segments exceed that of PAM. More PAA segments in copolymer make the PVA/CP DN gel have better elongation at break but weak in tensile strength and young’s modulus because of less PVA crystalline domains formed in the gel. The energy dissipation value for the double-network hydrogel decrease with the addition of PAA segments, whereas self-healing efficiency of PVA/CP DN gel increased. Anyway, this work provides more information to further understand the effects of composition on the properties of dual physically cross-linked PVA/CP DN hydrogel.
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高影响因子
Journal of Coatings Technology and Research
·
2017
·Vol. 14
·期 6
·1271-1278
·
IF 1.557
Zhu Xiao Dong,Liu Yu,Li Zhao
The physical and mechanical properties of wood and wood-based panels can be effectively improved by modification with nanoparticles. This paper focuses on effects of modifying veneer with titanium dioxide (TiO 2 ) nanoparticles on the performance of a waterborne coating and formaldehyde emission. Commercial waterborne varnish was used to apply a surface finish on the modified veneered panels. Changes caused by TiO 2 nanoparticle treatment that could affect the finishing performance were measured. The results showed slight increases in the weight and contact angle of the veneers treated with TiO 2 nanoparticles, whereas the modified veneered panels after surface finishing presented improved hardness at high nanoparticle loadings. Modification of the veneers by nanoparticles had a minor negative influence on the coating glossiness and adhesion due to a blocking effect between the coating film and the modified veneers. Formaldehyde emissions were considerably reduced due to degradation by the TiO 2 particles under UV-light irritation.
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