TALANTA
·
2020
·
IF 5.339
Yuting Li,Xing Guo,Yonghui Tian,Tianlong Zhang,Zewei Luo,Xiaojiao Liu,Cheng Qian,Jianxiong Dai,Yixiang Duan
Obtaining the fingerprints of polysaccharides was known to be notoriously difficult by ambient mass spectrometry due to their resistance for desorption and ionization. Ambient mass spectrometry technology has recently been recognized as a quick analysis tool for obtaining fingerprints, which is attributed to its characteristics of no sample pretreatment and easy operation under atmospheric pressure. However, it still remains a challenge for accurate identification of the fingerprints of macromolecular polysaccharides by ambient micro-fabrication glow discharge plasma (MFGDP). In this study, a simplified methylation method was introduced to realize rapid analysis of polysaccharide mixture by MFGDP with the assistance of a temperature-programmed system (TPS). At the optimal temperature of TPS, oligosaccharides , plant polysaccharides and polysaccharide mixtures were all well characterized by TPS-MFGDP. In the proposed method, the characteristic [M + NH 4 ] + adduct ions of oligosaccharides ions of oligosaccharides that are difficult for other ambient mass spectrometric methods were abundantly produced, making it possible to simultaneously identify a mixture of five or more polysaccharides. In addition, a supervised classification model which based on MS spectra, was used to classify seven typical hypoglycemic polysaccharides with excellent sensitivity, specificity and accuracy, indicating the good classification performance of the RF model constructed. Thus, the proposed mass spectroscopic method provides a cost effective, accurate and high throughput tool for identification and classification of polysaccharides, which is beneficial for studying the biological activity of polysaccharides.
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高影响因子
FOOD CHEMISTRY
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2020
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IF 6.306
Li Wang,Shuang Shao,Million Paulos Madebo,Yuanyuan Hou,Yonghua Zheng,Peng Jin
Effect of nano-SiO 2 packing on postharvest quality and antioxidant capacity of two different loquat cultivars (white-flesh ‘Qingzhong’ and red-flesh ‘Dawuxing’) were determined. Results showed that nano-SiO 2 packing significantly inhibited internal browning, retarded the decline of total soluble solids, titratable acidity, ascorbic acid content and extractable juice in both cultivars. Decay index of nano-SiO 2 packing in ‘Dawuxing’ and ‘Qingzhong’ was 53.25% and 42.84% lower than control after the day 12, respectively. Meanwhile, nano-SiO 2 packing enhanced the contents of individual phenolic compounds and soluble sugar compounds, induced higher superoxide dismutase and catalase activities, which contributed to improving 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging capacity. Furthermore, the contents of total soluble solids, ascorbic acid and soluble sugar were higher in ‘Qingzhong’ than those in ‘Dawuxing’, which dedicated to better quality. These results indicated that nano-SiO 2 packing was a promising approach in inhibiting decay, maintaining quality and expanding shelf life of loquats.
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高影响因子
Nanoscale
·
2020
·Vol. 12
·期 7
·4562-4572
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IF 6.895
Jing Wang,Xinyue Liu,Liang Huang,Jiening Jin,Chenxing Jiang,Daquan Li,Huimin Wen,Jun Hu
The ratiometric fluorescence technique is of great interest due to its visualization characteristics. The construction of a reliable fluorescent ratiometric nanoprobe for high-sensitivity visual quantification is highly sought after but it is limited by poor stability and controllability. Herein, we report a robust dual-emissive quantum dot nanohybrid with precise color tunability and demonstrate its potential as a two-signal-change ratiometric probe for visual detection. A novel assembly strategy was developed for spatially implanting hydrophobic green and red quantum dots (QDs) into a silica scaffold to form a dual-emissive hierarchical fluorescent silica nanohybrid. The fluorescence intensity ratio and color of the nanohybrid were precisely tailored by altering the amounts of green and red QDs. Particularly, after the alkylsilane-mediated phase transfer and exterior silica shell growth, the nanohybrid exhibited the well-preserved fluorescence features of the original QDs and robust optical/colloid stability. An inner filter-based ratiometric nanoprobe for the visual determination of melamine was ultimately devised by combining the spectra-overlapped two-colored fluorescent nanohybrid with analyte-specific gold nanoparticles. Furthermore, based on the reversible fluorescence signal changes in two-colored QDs induced by melamine, a logic gate strategy for melamine monitoring was constructed. The newly developed fluorescent ratiometric nanoprobe shows great prospects for the visual and quantitative determination of analytes in a complex biological matrix.
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高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 6
·3037-3054
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IF 4.21
Zhang Yunlei,Li Bing,Guan Wen,Wei Yanan,Yan Changhao,Meng Minjia,Pan Jianming,Yan Yongsheng
Nitrogen-doped carbon materials have attracted enormous interest in catalysis owing to their outstanding catalytic performance. In this work, nitrogen-doped carbonaceous catalysts (NCC) supported on inexpensive and naturally abundant halloysite nanotubes were successfully synthesized via precipitation polymerization, calcination, and sulfonation processes. The physical and chemical properties of the obtained catalysts were systematically characterized by different methods. The results indicated that NCC catalysts had mesoporous structures, excellent thermostability and acid-base bi-functional active sites. One-pot synthesis of 5-hydroxymethylfurfural (HMF) from glucose was performed to investigate the synthesized NCC catalysts. Benefiting from the synergistic effects of the acid-base bi-functional active sites, the highest HMF yield (62.8%) was achieved in an isopropanol-mediated DMSO system under optimal conditions. Moderate to excellent yields of HMF were also obtained from one-pot conversions of other carbohydrates, including inulin, sucrose, cellobiose, maltose and starch, with our developed catalytic system. The one-pot production of HMF from cellulose was also smoothly processed by the NCC bi-functional catalyst in an IL-based system. This work has developed a versatile strategy for designing nitrogen-doped carbonaceous catalysts that can be employed for the direct transformation of renewable carbohydrates to platform chemicals.
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JOURNAL OF ELECTRONIC MATERIALS
·
2020
·Vol. 49
·期 4
·2529-2538
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IF 1.774
Zhang Pengfei,Liu Yanxia,Chai Fengtao,Fan Yameng,Hou Aolin
Li 4 Ti 5 O 12 (LTO) composites modified with carbon nanotubes (CNTs) and carbon coating (LTO@C/CNTs) were synthesized by a simple solid-state reaction. The carbon-coated layers reduce the growth of the primary particles, inhibit interface side reactions and increase electron conductivity, so CNTs-modified LTO can form a conductive network and improve the diffusion path of lithium ions. The LTO@C/CNTs composites show a high-rate capability (150 mAh g −1 at 10 C, 145 mAh g −1 at 20 C) with good cycling performance (90.1% and 82.8% capacity retentions after 1000 cycles at 10 C and 20 C, respectively). In addition, superior electrochemical performance is also demonstrated in a full cell with a LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode and LTO@C/CNTs anode (97.1% capacity retentions after 200 cycles at 1 C). The carbon coating and CNTs-modified in LTO can reduce the polarization of potential difference and charge-transfer resistance, improve the diffusion coefficient of lithium ions, and lead to high rate performance and cycle stability.
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SENSORS AND ACTUATORS B-CHEMICAL
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2020
·
IF 7.1
Meiling Tian,Wenyue Xie,Ting Zhang,Yang Liu,Zhisong Lu,Chang Ming Li,Yingshuai Liu
This work reports a low-cost, fast and highly sensitive lateral flow immunoassay (LFIA) platform with Prussian blue nanoparticle (PBNP) as a new reporter, which efficiently mediates an on-demand cascade signal amplification by catalyzing oxidation of chromogenic reagent 3,3′,5,5′-tetramethylbenzidine (TMB). In this case, PBNPs are accumulated on the test line through the specific immune interaction, resulting in a blue-colored line. The colorimetric signal can be further amplified via the peroxidase mimic PBNP-catalyzed TMB oxidation to produce an insoluble blue-violet precipitate. Under an optimal condition, a limit of detection (LOD) at 10 pg mL −1 is achieved for rabbit IgG (RIgG) detection, which is 2–3 orders of magnitude better than the conventional LFIA strip using colloidal gold nanoparticle as a label. A macromolecular RIgG and a small molecular mycotoxin ochratoxin A (OTA) are also successfully analyzed in mimicking samples, demonstrating its good practicability of the proposed platform in a variety of fields.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2020
·
IF 3.807
Gengxin Hu,Nanxi Li,Yuwei Zhang,Hong Li
The electrochemical oxidative quinone-functionalization of tryptophan (Trp) residues, and the proton-coupled electron transfer properties between quinonized Trp (Trp=O) and its re-reduced species (Trp-OH) are investigated for potentiometric pH sensors. The Trp=O/Trp-OH couples are assembled on a graphite electrode using multiple cyclic voltammetry, and exhibit a pair of well-defined redox peaks at redox potential of 0.090 V (vs. SCE) at pH 7.0 and 298 K. The proton-coupled electron transfer properties of Trp=O/Trp-OH couples are dependent on electrode substrate material, incubation temperature and pH values, and Trp residue sources including amino acid, peptide and protein. The Trp=O/Trp-OH-based surface-confined exothermic electrode reaction rates show a decrease with increasing incubation temperature from 283 to 323 K at pH 5.0. Both of redox peak potential and open-circuit potential under optimum conditions have a good linear pH dependence between 1.0 and 12.0 with sensitivity of more than 52 mV pH −1 and relative standard derivation of 1.5%. The proposed potentiometric pH sensor has significant advantages of low cost, good stability and reproducibility, and strong anti-interference ability. The present study shows a new approach to endow Trp, Trp-containing peptides and non-conjugated proteins with analogous proton-coupled electron transfer performance to prosthetic groups of quinoproteins for monitoring pH changes in milk samples.
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高影响因子
Journal of Functional Foods
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2020
·
IF 3.701
Shuai Wang,Jiahui Pan,Zesheng Zhang,Xibo Yan
Fructooligosaccharides (FOS) are common prebiotics in the food industry. The two major methods employed in commercial production afford FOS in different compositions. To evaluate the exact impact of chemical compositions of FOS on probiotics, FOS are essayed in a “mixture” and a “pure” form. Probiotics show distinctively different preferences for the separated FOS. The metabolic intermediates and kinetics of the isolated FOS were investigated, indicating the crucial role of the structure and degree of polymerization (DP) of the FOS compositions. Extracellular enzymes preferentially degrade long-chained FOS for facilitating the uptake, whereas hydrolysis rates do not always positively determine the bacteria growth. Bifidobacterium strains have a highly selective and specific utilization pattern towards trisaccharide 1-kestose (GF 2 ), which contributes to its best growth promotion effect. In conclusion, the metabolic pathways and kinetics, the growth promotion effect of FOS on probiotics are directly related to the structures and the DP of the components.
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Nanoscale
·
2020
·Vol. 12
·期 12
·6852-6860
·
IF 6.895
E. Shuang,Quan-Xing Mao,Jian-Hua Wang,Xu-Wei Chen
Regulating the fluorescence of carbon dots (CDs) is important but highly challenging. Here, carbon dots with tunable dual emissions were facilely fabricated via modulating the polymerization and carbonization processes of o-phenylenediamine (OPD) with lysine (Lys) as the co-precursor and modulator, respectively. The self-polymerization/carbonization of the OPD molecules contributed to the blue/green emission of the OPD-derived CDs. The introduction of Lys in the CD fabrication process efficiently suppressed the carbonization of the OPD polymer chains and enhanced the self-polymerization of the OPD molecules. Meanwhile, the formed OPD-Lys co-polymer chains endowed the final CD product with a new green emission center. The dual-emissive CDs were distinctly sensitive to polarity fluctuations, providing a ratiometric fluorescence response towards solution polarity. Due to their specific distribution in the endoplasmic reticulum (ER), the as-prepared dual-emissive CDs successfully distinguished the polarity variations in ER under stress, which offers a new approach for the early diagnosis of cell injury.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Shuang Sun,Lijie Zhao,Jirui Yang,Xiaoqi Wang,Xiaoya Qin,Xinhua Qi,Feng Shen
A green, efficient, and facile ball-milling-assisted strategy was proposed to design an SO3H-containing solid acid for biomass valorization, where −SH groups were grafted on a natural clay attapulgite by wet ball milling with 3-mercaptopropyltrimethoxysilane (MTPS), followed by the oxidation of −SH to −SO3H with H2O2 at room temperature. The mechanism of the −SO3H functionalization by the ball-milling process was investigated, and the investigation indicated that the MTPS was grafted on the attapulgite through hydrolysis and condensation, which was induced by the mechanical forces of ball milling. Characterization, including SEM, EDX (energy-dispersive X-ray spectrometry), NH3-TPD, TGA, FT-IR, elemental analysis, and XPS, confirmed the success of −SO3H modification on attapulgite with a total acidity of 1.81 mmol/g. Harsh conditions involving a corrosive sulfonating agent, organic solvent, or high temperature in traditional methods are avoided in the developed approach. The prepared catalyst displayed a high activity toward the transformation of biomass-derived carbohydrates (glucose, fructose, cellobiose, sucrose, starch, and cellulose) into the more valuable chemical 5-hydroxymethylfurfural due to the synergy effect of MgO and −SO3H sites on the catalyst. Moreover, the catalyst showed excellent stability and recyclability for five recycles without loss of activity. This study provides a novel green method for the preparation of an SO3H-containing heterogeneous catalyst, which should have great application potential in other processes of biomass valorization.
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CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
·
2020
·
IF 0.936
Lan WU,Zhi-Wei LU,Ying MA,Jun-Jun ZHANG,Guang-Quan MO,Hai-Jun DU,Jian-Shan YE
A novel electrochemical non-enzymatic sensing system was fabricated based on carbon paste electrode (CPE) encapsulating copper metal-organic frameworks (Cu-MOF/CPE) for determination of glucose by chronoamperometry in alkaline media. The as-synthesized Cu-MOF exhibited high surface area and porous structures, and the presence of carbon pastes greatly improved the conductivity of the sensing electrode. This synergic effect led to the good catalytic activity of the resulting electrode toward glucose. Under the optimized experimental conditions, the oxidation peak currents were linearly dependent on glucose concentrations in a wide range of 5–3910 μmol/L and 3910–10950 μmol/L with a limit of detection (LOD) of 0.11 μmol/L and a short response time of 0.5 s. Moreover, the developed sensor showed long-time stability, excellent selectivity as well as high resistance towards interferences. This sensor was also applied to determination of glucose in serum samples with a satisfactory result, confirming its promising applications.
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FUEL
·
2020
·
IF 5.578
Guo Qiu,Biaohua Chen,Chongpin Huang,Ning Liu,Xiuliang Sun
Methods for the conversion of carbohydrates into 5-hydroxymethylfurfural (5-HMF), which is an important platform chemical, have been attracted extensive attention. In present study, Sn modified ionic liquid polymer (PIL-Sn) was prepared by one-pot polymerization of imidazole and epichlorohydrin, and utilized as a novel and efficient catalyst for 5-HMF production. The optimal 5-HMF yield of 51.1% with 99% conversion was obtained from glucose catalyzed by PIL-Sn in dimethyl sulfoxide at 130 °C with reaction time of 1 h. This catalytic system can also be applied for the transformation of other carbohydrates with satisfactory yields. The mechanism of PIL-Sn-catalyzed conversion of glucose to 5-HMF has been studied using density functional theory (DFT) calculations. The DFT results showed that the five-coordinated SnCl 5 - as a preferred species played an important role in the isomerization of glucose to fructose. This research provides a new strategy to design efficient catalysts for 5-HMF synthesis.
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