MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Xueying Chen,Yuxiao Hu,Zhijian Tan
Traditional three-phase partitioning (TPP) systems used for extracting and purifying bioactive substances typically consist of t -butanol and ammonium sulfate. However, the use of volatile and flammable organic solvents and high-concentration inorganic salts results in environmental pollution. Therefore, an innovative TPP based on deep eutectic solvents (DESs) and sugars (sugaring-out effect) was used to extract and preliminarily purify cucumber peroxidase (POD). Various factors affecting the extraction were optimized using response surface methodology (RSM). DES-8 (menthol: octanoic acid = 1:1) and sucrose were selected as the optimal constituents of TPP. Under these conditions, the sucrose concentration was 36% (w/v), DES: crude extract (v/v) was 1.4:1, system pH was not adjusted, extraction time was 6 min, and extraction temperature was 31 °C; the enzyme recovery and purification fold reached 84.53% and 5.28, respectively. Recycling experiments demonstrated that the DESs can be well recycled and reused after five recycles. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyze cucumber POD, which showed that the TPP system achieved primary purification of cucumber POD. This TPP is much greener and more efficient than traditional TPP systems and shows great application potential in the enzymes and proteins separation field.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2023
·
IF 5.2
Long Tian,Binyu Zhao,Juan Zhang,Xiaogang Luo,Fengshou Wu
The nanomaterials-based artificial enzymes have attracted great attention because of their high stability, good biocompatibility, high catalytic efficiency, and low cost in recent years. Herein, we synthesized a new covalent organic framework (COFs) through the dehydration reaction of 2,5-dihydroxyterephthalaldehyde and tetra-(4-aminophenyl) porphyrin , which was then used to fabricate the core-shell structured nanospheres (Fe 3 O 4 @COFs) by decorating on magnetic Fe 3 O 4 . In the presence of hydrogen peroxide (H 2 O 2 ), the Fe 3 O 4 @COFs nanospheres were able to catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue product (ox-TMB), indicating their high peroxidase-like activity. Based on this phenomenon, the Fe 3 O 4 @COFs was used as a colorimetric probe for sensitive and selective detection of H 2 O 2 and glucose. The detection limit (LOD) of H 2 O 2 was calculated to be 2.6 μM in a linear range from 0.1 to 4 mM, while the LOD of glucose was valued as 6 μM ranging from 0.05 to 0.9 mM. Finally, this method was applied in the determination of the glucose concentration in human serum with high accuracy. Thus, the as-prepared Fe 3 O 4 @COFs could be used as a highly sensitive and selective peroxidase mimic to detect hydrogen peroxide-related molecules, suggesting their great potential in biomedical application.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Yunpeng Liu,Zhongxin Chen,Yunyi Yang,Ren Zou,Binglu Deng,Linxin Zhong,Kian Ping Loh,Xinwen Peng
The major bottleneck in self-powered water splitting devices by renewable energy lies in the kinetically sluggish oxygen evolution reaction (OER), which only produces low-value oxygen. Herein, we explore sucrose electrooxidation as an alternative anodic reaction for production of valuable chemicals at a reduced electricity consumption. By developing a reversible redox cycle of Ni 2+ /Ni 3+ and Co 2+ /Co 3+ in the CoNi layered double hydroxide (LDH), the required voltage of sucrose oxidation for 100 mA cm −2 is reduced by 240 mV compared to oxygen evolution. The sucrose electrooxidation by CoNi LDH is a two-step reaction including the electrooxidation of Ni 2+ /Co 2+ to Ni 3+ /Co 3+ and the spontaneous reaction between Ni 3+ /Co 3+ and sucrose. By feeding with natural sugarcane juice, a solar-driven electrolyser is assembled for the co-production of value-added formic acid and hydrogen. Our work demonstrates a sustainable route for integrating hydrogen production and biomass electrooxidation for energy applications.
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Xueliang Zhang,Gisele LaPointe,Yang Liu,Xiaomeng Wang,Luyao Xiao,Xiaogan Zhao,Wei Li
In this study, we evaluated the impact of Lactiplantibacillus plantarum ( L. plantarum ) with ropy and non-ropy phenotypes on gel structure and protein conformation of fermented milk. Ropy L. plantarum (T1 & CL80) secreted EPS with high molecular weight (1.41 × 10 6 , 1.19 × 10 6 Da) and intrinsic viscosity (486.46, 316.32 mL/g), effectively enhances fermented milk viscosity and water holding capacity (WHC) (65.4%, 84.6%) by forming a dense gel structure. Non-ropy L. plantarum (CSK & S-1A) fermented milk gel’s high surface hydrophobicity and free sulfhydryl content caused high hardness and low WHC. Raman spectroscopy combined with circular dichroism analysis showed that high levels of α-helix (29.32–30.31%) and random roil (23.06–25.36%) protein structures are the intrinsic factors that contribute to the difference among fermented milk gels of ropy and non-ropy strains. This study provides a basis for understanding the structural variability of fermented milk gels using ropy or non-ropy lactic acid bacteria.
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高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Tianlu Zhao,Yangqing Li,Xuecheng Zhang,Haixia Lyu,Zenghong Xie
Here, the inner filter effect (IFE) was applied to construct a “turn off” mode up-conversion fluorescence and colorimetric dual-reading detection platform consisting of the chromogenic substance p-phenylenediamine (PPD) and NaYF 4 :Yb/Er@NaYF 4 core–shell up-conversion nanoparticles (UCNPs) for the detection of glucose and hydrogen peroxide (H 2 O 2 ) with high sensitivity and selectivity. In this strategy, hydrogen peroxide is produced in the process of glucose oxidation by catalyzing glucose oxidase (GOx). PPD is oxidized by H 2 O 2 under the action of horseradish peroxidase (HRP), resulting in the transformation into its oxidation product PPDox, whose absorption peak coincides with the emission peak of UCNP at 540 nm, which can significantly quench the fluorescence of UCNP. The quenching efficiency is related to PPDox production, so the relationship between the glucose content and the fluorescence changes of UCNP can be established to realize the sensitive detection of glucose. UCNPs modified by –COOH and the oxidation product of PPD were negatively charged, which increased the distance between donor and recipient due to electrostatic repulsion. It was not conducive to the occurrence of distance-dependent fluorescence resonance energy transfer (FRET), which was also verified by fluorescence lifetime test. Under the optimal experimental conditions, the linear ranges of hydrogen peroxide and glucose were 2.5 ∼ 50 and 5 ∼ 80 μmol/L with the detection limit (LOD) of 0.32 and 0.83 μmol/L, respectively, which were lower than of some reported approaches. Furthermore, the system could be applied to the detection of glucose in actual serum sample and the results were consistency of commercial glucose meters which indicated that the protocol was reliable and potential applications for clinical diagnosis.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2019
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IF 14.229
Junnan Wei,Ting Wang,Xuejuan Cao,Huai Liu,Xing Tang,Yong Sun,Xianhai Zeng,Tingzhou Lei,Shijie Liu,Lu Lin
Biomass-derived furanyl ethers, such as 5-alkoxymethylfurfurals (AMFs) and 2,5-bis(alkoxymethyl)furans (BAMFs), can be employed as promising biofuels or additives. The development of multifunctional catalysts for the efficient production of furanyl ethers from sugars through 5-hydroxymethylfurfural (HMF) as an intermediate is highly desirable but challenging, because multiple reactions including dehydration, etherification and hydrogenation get involved and the side reaction of sugars and HMF to form humins is inevitable. In this contribution, we found that the introduction of CuO resulted in the generation of Lewis acid sites at the cost of Bronsted acid sites over CuO-USY catalysts through the formation of Al-O-Cu(II) species. The dispersity of CuO particles and the amount of Lewis acid sites could be manipulated by adjusting the loading of CuO. If 5 wt% CuO was supported on USY zeolite to give a CuO(5)-USY catalyst, CuO particles with a high dispersity (36.4%) afforded abundant Lewis acid sites (457.1 μ mol/g). Lewis acid over CuO(5)-USY greatly promoted the acid-catalyzed dehydration of fructose to HMF and HMF etherification to AMFs, resulting in a HMF yield up to 86.2% from fructose and AMFs yields greater than 90% from HMF. Interestingly, a combination of CuO(5)-USY and a small amount of metallic Cu powder was able to offer desirable BAMFs yields by the reductive etherification of HMF under hydrogen atmosphere. As a result, 5-methoxymethylfurfural (MMF) of 79.6% and 2,5-bis(methoxymethyl)furan (BMMF) yield of 74.5% were achieved from fructose through HMF as an intermediate in the presence of CuO(5)-USY alone or with metallic Cu as a co-catalyst. Therefore, the above Cu-based catalyst system holds the promise to flexibly produce a family of AMFs or BAMFs from fructose via a facile two-step approach.
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NANOTECHNOLOGY
·
2019
·Vol. 30
·期 35
·355501
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IF 3.399
Youquan Zhong,Jie Yang,Xiaoying Yin,Jing Zheng,Na Lu,Min Zhang
Hollow-structured carbon materials play a crucial role in research of biosensors, energy storage and nanomedicine as a kind of material with advantages like high surface area, tunable pore volume, excellent mechanical properties, and good biocompatibility. Herein, we developed a simple, facile and controllable method for synthesis of Fe3O4 nanoparticles encapsulated in hollow carbon nanocages (FNHCs) with SiO2 nanospheres as a sacrificial template. Owing to the unique structure of multiple Fe3O4 nanoparticles cores integrated with N-doped carbon nanocages, the as-synthesized FNHCs exhibited greatly enhanced peroxidase mimicking activity with extremely high signal-to-noise ratio of ∼91 fold. Also, it was found that the FNHCs possessed a higher peroxidase-like activity than that of other similar-structured Fe3O4 architectures (e.g. Fe3O4@C NPs). The resulting steady-state kinetic curve demonstrated the enzymatic activity of FNHCs with classic Michaelis–Menton kinetics following a ping-pong mechanism. On the basis of the superior enzymatic activity, the FNHCs performed as a high-efficiency peroxidase mimic, realizing facile, label-free, highly sensitive/selective colorimetric detection of H2O2 and glucose. Furthermore, the colorimetric sensor successfully determined glucose in patients' serum samples with high accuracy and precision, suggesting great potential for real applications.
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FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Siquan Xu,Donghui Pan,Feng Hu,Yuanfeng Wu,Huazheng Wang,Yuan Chen,Hui Yuan,Lijing Gao,Guomin Xiao
In the presented work, a series of Cr/β zeolites were prepared and used as bifunctional catalysts with Brønsted and Lewis acidity in the conversion of biomass-derived carbohydrates to 5‑hydroxymethylfurfural (HMF). The physicochemical properties of all catalysts were characterized by ICP-AES, N 2 physisorption , solid-state 27 Al NMR, XRD, SEM-EDX, UV–Vis, XPS , Raman, NH 3 -TPD and Py-FTIR techniques. It was found that the catalysts with appropriate total acidity, ratio of Lewis to Brønsted acid sites and acid density appear to be beneficial for HMF formation. Under mild reaction conditions, a superior 72% HMF yield with 83% selectivity was achieved from glucose in the H 2 O/THF biphasic system by using the 0.4-Cr/β zeolite catalyst. Moreover, the results of the stability evaluation showed that the catalytic activity of the 0.4-Cr/β zeolite was not significantly lost after four consecutive cycles, and the framework remained intact. Therefore, the catalytic approach proposed in this study is believed to provide potential prospects for the production of HMF from biomass material refining in the future.
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CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Jun Zhang,Kaijun Dong,Weimin Luo
A facile and mild method for the catalytic production of 2,5-dimethylfuran (DMF) from 5-hydroxymethylfurfural (HMF) was developed, which utilized commercial PdCl 2 as the catalyst together with the green, non-toxic and low-cost hydride source, polymethylhydrosiloxane (PMHS). A synergistic effect among hydrogen donor, in situ generated metallic Pd 0 species and acid site HCl in the reaction played a key role in DMF formation. Gratifyingly, the desirable yield of hydrodeoxygenation product DMF as high as 89.7% from HMF was attained at room temperature (298 K) in 0.5 h. Meanwhile, biomass derived sugars also could be converted into DMF in relative high efficiency via a one-pot reaction in the present system. A plausible pathway for the hydrodeoxygenation of HMF into DMF in the present system was also proposed. The study thus highlights a new perspective for a simple, green, and efficient hydrodeoxygenation of biomass derivatives under milder conditions, employing a readily available, inexpensive and practical catalytic system of PdCl 2 -PMHS-ethanol, but without any external hydrogen supplies and pre-reduction treatments.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Mengli Xu,Linyu Wang,Yi Xie,Yonghai Song,Li Wang
Here, a covalent organic framework with multiple redox-active state synthesized by amine-aldehyde condensation reaction between 4,4′,4′'-(1,3,5-triazine-2,4,6-triyl) trianiline and 2,5-dihydroxy terethaldehyde (COF DHTA-TTA ) was used as novel electrochemical sensing and biosensing platform at first time. The COF DHTA-TTA was demonstrated to be two-dimensional nanosheets with highly ordered conjugated structure and uniform mesopores about 3.67 nm. Electrochemical studies revealed that a ratiometric electrochemical sensor could be constructed by using COF DHTA-TTA itself as electroactive materials to determine hydrogen peroxide (H2O2) and pH level based on both current and potential signals. The single electrochemical sensor could monitor H2O2 concentration from 5.66 μM to 400 μM and pH level ranging from 11.0 to 3.0. Considering that the COF DHTA-TTA had good catalytic activity for oxygen reduction reaction in 0.2 M PBS (pH = 7.0), glucose oxidase was further loaded on COF DHTA-TTA via its nanosized pores and abundant active sites originated from N-doped skeleton, and the glucose biosensor exhibited good performances for glucose detection from 1.26 μM to 6.0 mM at −0.30 V, as well as from 0.60 μM to 6.0 mM at −0.53 V. The work provided good examples to construct electrochemical sensors based on redox-active COF.
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ANALYTICA CHIMICA ACTA
·
2018
·
IF 5.123
Ying Zhang,Wang Ren,Yu Zhu Fan,Jiang Xue Dong,Hui Zhang,Hong Qun Luo,Nian Bing Li
A simple and label-free fluorescence turn-on method is proposed for the discrimination and detection of epinephrine (Ep) and dopamine (DA) via polyethyleneimine (PEI)-initiated in situ copolymerization and excitation wavelength switch. The PEI solution in the presence of Ep, DA and the mixture of Ep and DA are denoted as P Ep-PEI , P DA-PEI and M Ep+DA , respectively. In this study, PEI aqueous solution medium initiates the auto-oxidization of Ep and DA and the bioinspired copolymerization. These resultant copolymers emit yellow-green fluorescence color with a fluorescence emission maximum at 515 nm. Interestingly, these fluorescent copolymers exhibit distinct different excitation spectra, although Ep and DA are structurally very similar. P DA-PEI exhibits only one excitation peak at 385 nm, and P Ep-PEI shows dual-excitation mode with two significant excitation peaks at 328 nm and 405 nm, respectively. M Ep+DA also shows dual-excitation mode with two excitation peaks at 330 nm and 395 nm, respectively. Thus, individual Ep, DA, and their mixture can be discriminated based on the different excitation spectral shapes and peak locations of P Ep-PEI , P DA-PEI and M Ep+DA . Furthermore, the quantitative analysis of Ep and DA in mixture can also be achieved by switching excitation wavelength between 330 and 395 nm and monitoring the fluorescence emission intensity of M Ep+DA at 515 nm. The fluorescence intensity of M Ep+DA only related to the concentration of Ep when excited at 330 nm. Moreover, the concentration of DA can also be calculated by subtracting the fluorescence intensity of P Ep-PEI from the total fluorescence intensity when excited at 395 nm. The resultant method has been used to simultaneously detect Ep and DA in human urine samples. The proposed fluorescence system is facile, eco-friendly, low-cost, and time-saving, and also provides a new and simple path for discriminating analogues.
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Molecular Catalysis
·
2018
·
IF 0
Yueqing Wang,Xiaohai Yang,Hongyan Zheng,Xianqing Li,Yulei Zhu,Yongwang Li
The mechanism for the formation of furfural by dehydration of d -fructose via selective carbon-carbon (C C) bond cleavage was investigated over beta zeolite (Hβ). Several different pore size zeolites were employed to determine the shape selectivity of fructose isomers. Zeolitic pore sizes that smaller than the kinetic diameter of cyclic fructose also produced yield furfural (∼22.5%), while the high yield (66.0%) of hydroxymethylfurfural (HMF) can be achieved over large pore zeolite (USY zeolite), which could accommodate the cyclic fructose. These results indicated that the furfural formation likely began with acyclic fructose. In situ 13 C NMR and GC MS studies, using labeled 13 C-1-fructose as substrate, suggested that the conversion of fructose to furfural involved with splitting of the C5-C6 bond. Furthermore, the C1 compound from the cleavage of C C bond was identified as formaldehyde, inferring that the selective scission of C C bond was ascribe to the retro-aldol reaction. Interestingly, in situ NMR studies implied that the acyclic fructose mainly derived from pyranose forms. In addition, compared with glucose, fructose directly converted to furfural at the higher yield and reaction rate.
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