DYES AND PIGMENTS
·
2020
·
IF 4.613
Qingxiao An,Qinlu Lin,Xiaohui Huang,Rongju Zhou,Xin Guo,Weizhen Xu,Suyan Wang,Dong Xu,Huan-Tsung Chang
Preparation of carbon dots (C dots) with strong emission at long wavelengths is an ongoing goal to their advanced applications, especially in bioanalysis. For sensing Fe 3+ and ascorbic acid (AA), we prepared C dots with a large Stokes shift using o- phenylenediamine (OPD) as the carbon source through an electrochemical method . During the electrolysis, OPD undergoes polymerization, carbonization , and passivation at the platinum anode to form C dots. These C dots were characterized by UV–Vis spectroscopy, transmission electron microscopy , Raman spectroscopy , X-ray photoelectron spectroscopy (XPS), and FT-IR spectroscopy. They are composed of C, N, O, H elements, having a maximum of emission at 570 nm and a supreme excitation at 261 nm, with a Stokes shift of 309 nm. A new emission at 350 nm emerged with their exposure to Fe 3+ and the intensity rises upon increasing Fe 3+ , while the emission intensity at 570 nm decreases. Thus, dissimilar to the usual quenching strategy, a novel ratiometric fluorescent sensor based on the fluorescence intensity ratio (F 350 /F 570 ) of the C dots at 350 nm and 570 nm has been developed for quantitation of Fe 3+ with a limit of detection (LOD) of 0.16 μM and high selectivity toward Fe 3+ against K + , Cu 2+ , and Fe 2+ . With evidence of decreased C–N C and C–O/N–O in XPS and increased content of C O/N O and N–H, we suggested the complexation of Fe 3+ with the surface groups led to the changes in chemical bonds accounting for their optical property variation. Furthermore, AA can quench the fluorescence of C dots at 570 nm and Fe 3+ -treated C dots (incubated with 50 μM Fe 3+ ) at 350 nm by a static mechanism. Accordingly, two assays toward AA were developed with LODs of 0.12 μM and 0.32 μM by using C dots and Fe 3+ -treated C dots, respectively. Especially, both AA assays exhibited excellent selectivity under various substances including those with strong reducing ability such as pyrogallic acid, sodium citrate, tea polyphenol, and dithiothreitol. The applications of the assays were validated with the quantitation of Fe 3+ in urine and AA in beverages. Electrochemical method is a significant approach to develop novel C dots even using the same carbon sources as in other methods.
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FOOD CHEMISTRY
·
2020
·
IF 6.306
Manli Guo,Jingtian Chi,Chi Zhang,Minglin Wang,Hui Liang,Juying Hou,Shiyun Ai,Xiangyang Li
In this work, one kind of zeolite imidazole frameworks containing bovine serum albumin stabilized Au nanoclusters (AuNCs), β-galactosidase (β-Gal) and glucose oxidase (GOx) (AuNCs/β-Gal/GOx@ZIF-8) were obtained to detect lactose. Compared with other fluorescent nano-materials, AuNCs show distinct advantages as a guest species in ZIF-8, specifically their extremely small size (<1 nm), simple synthesis, excellent biocompatibility and high stability. Furthermore, the bovine serum albumin on their surfaces can promote the formation of ZIF-8 coating; thus, AuNCs were co-encapsulated in ZIF-8 with the enzymes together. X-ray diffraction (XRD) analysis indicates the composite possesses the similar crystalline structure with pure ZIF-8. Fluorescence microscope images, Fourier transform infrared spectra and energy dispersive X-ray spectroscopy indicate the presence of AuNCs in the composite. Owing to the high local concentrations of the fluorescent probe and the quenching agent in AuNCs/β-Gal/GOx@ZIF-8, the quenching rate was enhanced 3.4-fold that of free AuNCs and enzymes in solution.
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高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Nannan Wang,Yong Hong,Terence Xiaoteng Liu,Qi Wang,Jiarui Huang
A microporous–mesoporous carbon has been successfully prepared via carbonization of sucrose followed by heat treatment process. The obtained porous carbon possesses abundant micropores and mesopores, which can effectively increase the sulfur loading. The composite exhibited a remarkable initial capacity of 1185 mAh g −1 at 0.2 A g −1 and maintained at 488 mAh g −1 after 200 cycles, when employed for lithium‒sulfur batteries. Moreover, the composite displayed enhanced rate capabilities of 1124, 914 and 572 mAh g −1 at 0.2, 0.5 and 1.0 A g −1 . The outstanding electrochemical capabilities and facile low‒cost preparation make the new microporous–mesoporous carbon as an excellent candidate for lithium sulfur batteries .
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高影响因子
NANOTECHNOLOGY
·
2020
·Vol. 31
·期 45
·455503
·
IF 3.551
Mingzhu Wang,Xue Wang,Shiya Feng,Daiping He,Ping Jiang
Ever-growing efforts have been devoted to developing cost-effective and earth-abundant electrocatalysts with high-performance in biosensing and energy energy conversion. In this work, amorphous nickel-phosphorus (Ni-P) nanoparticles anchoring on Ni foam (Ni-P/NF) were prepared through a facile electroless deposition approach. The morphology and composition were characterized by scanning electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy. As an integrated anode, Ni-P/NF exhibits high performance towards glucose electrochemical sensing, with a high sensitivity of 13.89 mA mM−1 cm−2, a low detection limit of 1 µM, a wide detection ranges from 2 µM to 0.54 mM, and a quick response (<10 s), as well as good selectivity and reliability for real sample analysis in human serum. In addition to electrocatalytic glucose oxidation, Ni-P/NF shows remarkable catalytic activity towards oxygen evolution reaction (OER) in alkaline solution and it only needs an overpotential of 360 mV to afford 50 mA cm−2. Moreover, Ni-P/NF shows excellent durability under alkaline OER condition. All these results demonstrate Ni-P/NF as highly efficient integrated anode in both biosensing and energy conversion.
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高影响因子
RENEWABLE ENERGY
·
2020
·
IF 6.274
Hongming Zhang,Guochang Xu,Lu Zhang,Wenfeng Wang,Wenkang Miao,Kangli Chen,Lina Cheng,Yuan Li,Shumin Han
Sodium borohydride (NaBH 4 ) is an ideal chemical carrier of hydrogen due to its high hydrogen release capacity via hydrolysis, however the reaction is restricted by a competent catalyst. Herein, we present an efficient catalyst – ultrafine non-noble Co nanoparticles supported on carbon nanospheres (CNSs) (CNSs@Co), for hydrogen generation from NaBH 4 hydrolysis in alkaline media . The ultrafine Co nanoparticles distribute evenly over the surface of the CNSs by adjusting solubility of a by-product – NaBO 2 within ethanol. The as-prepared CNSs@Co catalyst has a glorious catalytic activity for hydrogen evolution of NaBH 4 . It shows a high hydrogen generation rate (HGR) of 7447 mL H 2 . min − 1 ⋅ g M − 1 at 30 °C, and a low activation energy of 40.79 kJ mol −1 . Besides, the catalyst exhibits a stable cycling capability in a consecutive cycling test. The outstanding catalytic performance of the CNSs@Co catalyst could attribute to the ultrafine size of the Co nanoparticles (∼7 nm) and its uniform dispersion supported by the CNSs. We believe the catalyst together with its synthetic method will provide a probable strategy to promote the hydrogen generation from NaBH 4 .
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ACS Applied Bio Materials
·
2020
·
IF 0
Wei Ding,Haibo Liu,Weiwen Zhao,Jie Wang,Linlin Zhang,Yuewei Yao,Cheng Yao,Chan Song
Recently, the development of nanozymes with high catalytic performance is gaining more and more attention due to the ever-growing demands for their practical applications. The elaborate design of its morphology has demonstrated to be an effective approach to improve the performance of these nanozymes. Herein, a hybrid of iron disulfide nanoparticles (FeS2 NPs) encapsulated by two-dimensional (2D) carbon nanosheets (NSs), denoted as FeS2@C NSs, demonstrates both superior peroxidase-like activity and excellent stability. The incorporation of 2D carbon sheets endows the proposed FeS2@C nanozymes with high specific surface area, providing abundant active sites to facilitate the contact with substrates. Moreover, the embedded FeS2 NPs are kept from aggregation due to the encapsulation and confinement of 2D carbon sheets, avoiding the conventional failure of single-component nanozymes. Based on glucose oxidase (GOx) and the elaborately designed FeS2@C nanozymes, a colorimetric method for glucose detection is then developed with excellent simplicity and sensitivity. The detection limit of the sensing platform is as low as 0.19 μM for a glucose assay. More notably, this method can be successfully employed for the glucose assay in some real samples, indicating the great potential of this FeS2@C NS-based nanozymes in the fields of biotechnology and clinical diagnostics.
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PubMed
Pharmaceutics
·
2020
·Vol. 12
·期 8
·731
·
IF 4.421
Kaixiang Zhou,Yuanyuan Yan,Dongmei Chen,Lingli Huang,Chao Li,Kuiyu Meng,Shuge Wang,Samah Attia Algharib,Zonghui Yuan,Shuyu Xie
Developing a targeted oral delivery system to improve the efficacy of veterinary antibiotics and reduce their consumption and environmental risks is urgent. To achieve the duodenum-targeted release of tilmicosin, the enteric granule containing tilmicosin-loaded solid lipid nanoparticles (TIL-SLNs) was prepared based on its absorption site and transport characteristics. The in vitro release, release mechanisms, stability, palatability, and pharmacokinetics of the optimum enteric granules were studied. The intestine perfusion indicated that the main absorption site of tilmicosin was shifted to duodenum from ileum by TIL-SLNs, while, the absorption of TIL-SLNs in the duodenum was hindered by P-glycoprotein (P-gp). In contrast with TIL-SLNs, the TIL-SLNs could be more effectively delivered to the duodenum in intact form after enteric coating. Its effective permeability coefficient was enhanced when P-gp inhibitors were added. Compared to commercial premix, although the TIL-SLNs did not improve the oral absorption of tilmicosin, the time to reach peak concentration (Tmax) was obviously shortened. After the enteric coating of the granules containing SLNs and P-gp inhibitor of polysorbate-80, the oral absorption of tilmicosin was improved 2.72 fold, and the Tmaxwas shortened by 2 h. The combination of duodenum-targeted release and P-gp inhibitors was an effective method to improve the oral absorption of tilmicosin.Keywords:antimicrobial-resistance;tilmicosin enteric granules;P-glycoprotein;duodenum-targeted release;oral absorption;reduce consumption
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2020
·
IF 7.183
Liang Cheng,Mengxiao Zhang,Chuanjie Fang,Weilin Feng,Liping Zhu,Youyi Xu
Loose nanofiltration (NF) membrane with pore radius approaching 1 nm and positive charges can be valuable alternative to commercial available negatively charged polyamide NF membrane in specific applications, such as removal of hardness and heavy metal ions and selective separation of dyes/salts mixture. In this work, positively charged poly( N -vinyl imidazole) (PVI) gel-filled loose NF membranes were developed by asymmetric gel-filling upon an asymmetric ultrafiltration (UF) support via UV-initiated surface grafting polymerization and post-quaternization. Compared to the polyamide NF membranes, these membranes displayed a comparable salt rejection ability due to their stronger Donnan exclusion effect. A rigorous three-parameter transport model (TPM) considering steric, Donnan and dielectric exclusion on ions partitioning via effective pore radius ( r p ), membrane charge density ( X d ) and averaged pore dielectric constant ( ε p ), was used to analyze the membrane parameters. Then the gel conformation model (GM) treating confined gel as semi-dilute polymer solution with a characteristic correlation length ( ξ ) was applied to analyze these gel composites. The results suggest that the gel polymer volume fraction ( φ ) is decisive in the gel mesh size (viewed as membrane pore size) and gel permeability. Surface porosity of the asymmetric UF base is a limiting factor in membrane permeability. The joint modelling analysis can clarify the membrane structure-properties relationship, performance limits and potentials of the gel-filled NF membrane and hence facilitate structure design and optimization.
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高影响因子
ANALYTICAL LETTERS
·
2020
·
IF 1.467
Meijuan Ren,Huan Wang,Yuanyuan Liu,Qin Ma,Wenjing Jia,Mingzhu Liu,Huiju Wang,Yongchang Lu
Amino-MIL-53(Al) nanosheets were synthesized by a hydrothermal reaction and were employed as a fluorescent probe because of their high quantum yield and excellent stability. The amino-MIL-53(Al) nanosheets have a maximum fluorescence emission peak at 435 nm using an excitation wavelength of 335 nm. The fluorescent intensity of luminophor at 435 nm was linearly quenched when mercury (II) (Hg2+) was added, which occurred due to the adsorption of Hg2+ onto the luminophor surface. Under these conditions, the fluorescent signal of the system is in the “turn-off” state. Following the addition of glutathione (GSH) into the system, the quenched fluorescence intensity may be partially restored based on the reaction between glutathione and Hg2+. In this condition, the fluorescent signal of the amino-MIL-53(Al)-Hg2+ system is in the “turn-on” state. Therefore, the amino-MIL-53(Al) nanosheets were successfully used as a “turn-off-on” fluorescent sensing system to determine the concentrations of Hg2+ in Tibetan medicine and glutathione in rabbit serum. A good correlation coefficient was obtained between the quenching of the fluorescence intensity of luminophor and the concentration of Hg2+ using the optimized conditions. A linear range was acquired from 1.96 nM to 38.27 μM with a detection limit of 0.23 nM of Hg2+ based upon a signal-to-noise ratio of three. For glutathione, the linear dynamic range was from 210 nM to 15.25 μM with a detection limit equal to 8.11 nM based upon a signal-to-noise ratio of three. This developed sensor system has the advantages of high selectivity, favorable sensitivity and simple operation for the determination of Hg2+ and glutathione in real samples.
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高影响因子
Journal of Water Process Engineering
·
2021
·
IF 5.485
Wen-Juan Zeng,Chuang Li,Yue Feng,Shu-Huan Zeng,Bing-Xin Fu,Xiao-Liang Zhang
GO/CNTs composite membranes with fine hierarchical nanostructure were facilely fabricated by intercalation with 1D carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) into 2D graphene oxide (GO) nanosheets for efficient organic wastewater treatment. By characterization results of XRD, Raman, FTIR, TEM and water contact angle, MWCNTs-COOH was successfully to be intercalated into GO lamellar interlayers with grafting reactions, which would improve water permeated flux and stability of membrane. The influences of GO/CNTs ratios, loading amounts, CNTs types and support types on the membrane separation performance were systematically investigated towards methylene blue dye solution. For the GO/CNTs composite membranes prepared under the optimized conditions, the permeated flux of 34.4 L m −2 h -1 and rejection over 99.7 % were obtained towards methylene blue solutions under the transmembrane pressure difference of 0.9 bar, respectively. Compared with pristine GO membrane, it exhibited a nearly 10-fold water permeated flux improvement meanwhile maintaining high rejection. Moreover, the electrostatic interaction and size exclusion effects were synergistically contributed to be responsible for the efficiently separation properties of the GO/CNTs membranes towards different positively/negatively charged dyes and neutral organic molecules. Such the GO/CNTs membranes also exhibited good chemical stability for acid resistance with highly efficient separation performance.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2020
·
IF 4.495
Youlin Jiang,Dewei Ni,Bowen Chen,Jun Lu,Feiyan Cai,Xuegang Zou,Chunjing Liao,Hongda Wang,Shaoming Dong
In this work, 3D-C f /HfC-SiC-based composites were fabricated and optimized via reactive melt infiltration (RMI) of Si into porous C f /HfC-C preforms prepared by a sol-gel processing. The physical and chemical processes involved during the fabrication were identified and analyzed in details. It is revealed that fibers and interphase of the composites can be eroded during carbothermal reduction process, which can be further aggravated during RMI, with the formation of Hf-containing substance on the fibers surface. The fibers and interphase degradation is mainly induced by the reactions between HfO 2 and C/SiC interphase layers at elevated temperatures. Accordingly, a two-step carbothermal reduction treatment was proposed for the optimization of the fabrication procedure. As a result, less fiber/interphase erosion and improved mechanical properties are achieved in the composites, with the bending strength increased by ∼49 % (from 214.1 ± 15.7 MPa to 319.0 ± 26.0 MPa).
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高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 16
·9699-9710
·
IF 4.21
Zhu Wenju,Hao Shuaishuai,Yang Mingyang,Cheng Bowen,Zhang Jimei
Abstract In the present research, a glycosyl cross-linking coordination chelate flame retardant was designed to enhance durable flame retardancy of cotton fabrics. It was a halogen-free, non-formaldehyde boron acid and phytic acid ammonium salt synergistic flame-retardant system. The flame retardancy and durability of flame retardants prepared by different saccharides were investigated. Results showed that raffinose was the best cross-linking reagent compared with the other monosaccharides and oligosaccharides. The r affinose as cross-linking reagent prepared g lycosyl cross-linking b oron acid and a mmonium salt of p hytic acid flame retardant (r-GBAP) (100 g/L) can obtain the shortest char length of 56 mm and the largest limiting oxygen index (LOI) value of 37.4%. A lower r-GBAP concentration can get good flame retardancy, due to adopt the three curing cycles process. FTIR, XPS, LOI, TG and SEM testing and characterization techniques were used to analyze and research the flame retardancy, durability, thermal oxidation stability and flame-retardant mechanisms of r-GBAP and the treated cotton fibers. Graphic abstract
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危险品化学品经营许可证（带存储）