GREEN CHEMISTRY
·
2015
·Vol. 18
·期 7
·2147-2154
·
IF 8.02
Alei Zhang,Cong Gao,Jing Wang,Kequan Chen,Pingkai Ouyang
In this study, we present an efficient affinity adsorption–enzymatic reaction integrated approach to produce N-acetyl-D-glucosamine (GlcNAc) from crude chitin powders (CP). Chitinase was first purified from the crude enzyme mixture by affinity adsorption on the CP substrate, with ∼92.7% recovery of the enzyme achieved within 10 minutes in the presence of 20 g L−1 of CP under optimized conditions. The chitinase then efficiently converted 40 g L−1 of CP to 39.3 g L−1 of GlcNAc in a batch enzymatic reaction for 4 days, achieving nearly 100% conversion of the substrate CP. The product GlcNAc was easily separated from hydrolysates after destaining, concentrating, crystallizing and drying processes with a high purity of 98%. In addition, the chitinase can be conveniently reused for several batches by the affinity adsorption–enzymatic reaction approach, giving an average yield of 29.6 g L−1 of GlcNAc based on 30 g L−1 of CP as the substrate.
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BIOSENSORS & BIOELECTRONICS
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2022
·
IF 12.545
Jianwei He,Xiaoyan Zhang,Yuanyi Qian,Qiyao Wang,Yunpeng Bai
The environmental accumulation of organophosphates is a serious threat to public health. To detect these xenobiotics , a broad range of sensors has been developed in past decades. However, sensors with high sensitivity and a capability for degrading organophosphates are rare. In this study, “smart” whole-cell biosensors were created by combining synthetic biology approaches with the bacterial quorum sensing (QS) mechanism. The engineered whole-cell biosensor pUC57-QS-DSF-F42 L/E coli DH5α can sense a wide array of phenolic compounds including phenol and p -nitrophenol (p-NP). By optimizing the genetic circuits, the phenol and p-NP detection limits reached 0.1 and 1 μM, respectively. Importantly, by replacing the fluorescence-generated reporter sf GFP with MP-degrading enzyme Po OPH M2 , the whole-cell biosensor pUC57-OPH-QS-DSF-F42 L/E coli DH5α actively degraded 10 and 100 μM methyl parathion (MP), a typical organophosphate pesticide , which was artificially added to the cell culture at different time points in five consecutive degrading experiments, demonstrating its MP sensing and degrading capabilities. The universal design of this new biosensor can be used to create more efficient biosensors to detect and degrade various pollutants in the environment for rapid testing and bioremediation.
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MINERALS ENGINEERING
·
2022
·
IF 5.479
Sihui Wu,Jianjun Wang,Liming Tao,Ruihua Fan,Cong Wang,Wei Sun,Zhiyong Gao
In the flotation separation of chalcopyrite and pyrite, the commonly used high-lime process often causes problems such as losses of precious metals, blockage in pipelines and environmental pollution. In this study, acetylacetone (AA) was used as a novel collector to separate chalcopyrite from pyrite without adding limes. The flotation results indicate that AA can selectively separate chalcopyrite from pyrite without depressants at pH 9.0. Flotation kinetics and entrainment calculations show that compared with potassium ethyl xanthate (KEX), AA reduces pyrite entrainment and produces the concentrate with a higher Cu grade and a higher separation efficiency. Solution chemistry calculations show that enolate (AAE - ) and ketone (AAK) are the dominant species of AA at pH 9.0. Contact angle measurements, zeta potential measurements and Fourier transform infrared (FTIR) analysis indicate that the dominant species of AA chemically adsorb onto chalcopyrite surfaces at pH 9.0 while the adsorption on pyrite is minimal. Density functional theory (DFT) analysis reveals that the Fe atoms on chalcopyrite are the active sites interacting with AA to form six-membered ring complexes. The selective adsorption of AA relies on the spatial distribution and reactivity of Fe atoms on the commonly exposed cleavage surfaces of chalcopyrite and pyrite. After surface relaxation, a layer of Fe atoms appears on the outermost layer of chalcopyrite (1 1 2) surface, which is beneficial for the adsorption of AA species while a layer of S atoms for pyrite (1 0 0) surface. The Fe (III) on chalcopyrite (1 1 2) surface has a higher reactivity than the Fe (II) on pyrite (1 0 0) surface, leading to a higher adsorption energy of AA species on the chalcopyrite. Therefore, this acetylacetone-based lime-free process has a great potential for industrial application in the separation of chalcopyrite from pyrite.
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DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 15
·5459-5464
·
IF 4.099
Mengmeng Zhu,Yunjie Zhou,Yue Sun,Cheng Zhu,Lulu Hu,Jin Gao,Hui Huang,Yang Liu,Zhenhui Kang
The oxygen evolution reaction (OER) is a promising energy conversion system, which has been studied a lot in recent years. However, owing to the high overpotential and sluggish kinetics of the OER, an efficient electrocatalyst is necessary to lower the overpotential and accelerate the reaction. In this paper, we report a cobalt phosphide (CoP)/carbon dots (CDs) composite as an electrocatalyst for the OER for the first time. A facile two-step method was used to synthesize the CoP/CDs composite and the concentration of CDs in the composite was further regulated. The experimental results show that when the amount of CDs in the composite is 6 mg (28.79 wt%C), the obtained CoP/CDs composite exhibits optimal electrocatalytic activity (with an overpotential of 400 mV in 1 M KOH at a current density of 10 mA cm−2) and high stability towards the OER. The good electrocatalytic activity of the composite is attributed to the small size of CoP and CDs and rapid electron transfer of CDs.
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ACS Applied Nano Materials
·
2022
·
IF 6.14
Sainan Cao,Bingjie Zou,Jingxia Yang,Jinjie Wang,Huangdi Feng
A heterogeneous catalyst CuO–CeO2 with a hollow structure was successfully synthesized by assembling CuO on the outer surface of CeO2 hollow spheres through a layer-by-layer deposition strategy. Further reduction under a H2 atmosphere was carried out to modify its surface state, resulting in sample r-CuO–CeO2. The catalysts were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform-infrared spectroscopy (FT-IR). SEM and TEM showed that the synthesized catalysts had a hollow sphere structure, which can expose more active sites and promote mass transfer. The results of XPS revealed that the content of Cu0&Cu+ increased from 13.6 to 19.0% after H2 reduction, which was conducive to the activation of terminal alkyne to promote the annulation/A3-coupling reaction. The conversion of this cascade reaction with the r-CuO–CeO2 catalyst can reach more than 95%, while the value was only 55% by using CuO–CeO2 as a catalyst. Moreover, the r-CuO–CeO2 catalyst showed a good recycle property and group compatibility in the general applicability of the cascade annulation/A3-coupling reaction, providing a series of propargylamine derivatives in good chemoselectivity.
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JOURNAL OF CHROMATOGRAPHY A
·
2019
·
IF 3.858
Wei-Qi Xie,Yi-Xian Gong,Kong-Xian Yu
A fast, convenient and commercially available approach for analyzing humic acid content in fertilizer using headspace gas chromatography (HS-GC) is presented in this paper. Humic acid is converted into carbon dioxide based on the oxidation of humic acid in strong acidic medium and can be measured via automatic HS-GC. Conditions for the alkaline extraction and the humic acid oxidation process are also optimized. The new technique proved to be precise (RSD ≤ 3.59%) and accurate (relative errors≤9.46% as compared with the spectrophotometric approach). The newly established technique presents a practical tool to routinely analyze humic acid content in fertilizer during the fertilizer production.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2012
·
IF 2.098
Yunchang Fan,Sheli Zhang,Qiang Wang,Junhai Li,Haotian Fan,Dongkai Shan
The interaction of an amino-functionalized ionic liquid, 1-(2-aminoethyl)-3-butylimidazolium bromide ([NH 2 C 2 C 4 im]Br) with two enzymes, pepsin and papain was investigated using fluorescence spectroscopic technique. It is found that [NH 2 C 2 C 4 im]Br has strong ability to quench the intrinsic fluorescence of pepsin and papain. Quenching mechanisms are considered as static quenching for papain and dynamic quenching for pepsin, respectively. The binding constants and the number of binding sites ( n ) of [NH 2 C 2 C 4 im]Br to papain were calculated at different temperatures. The thermodynamic parameters such as free energy change (Δ G ), enthalpy change (Δ H ) and entropy change (Δ S ), were calculated by thermodynamic equations. The values of Δ G , Δ H and Δ S suggest that interaction of [NH 2 C 2 C 4 im]Br with the two enzymes is spontaneous. Hydrogen bonding and van der Waals interactions play important roles in the binding process of [NH 2 C 2 C 4 im]Br to papain. However, hydrophobic interaction is the main driving force for the interaction of [NH 2 C 2 C 4 im]Br with pepsin. The results of three-dimensional fluorescence spectra show that [NH 2 C 2 C 4 im]Br has no obvious effects on the polypeptide structures of the two enzymes. Additionally, the [NH 2 C 2 C 4 im]Br-containing system can slightly increase the activities of the two enzymes.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Zhiyun Li,Saili Xu,Menglan Li,Wenhao Xu,Dang Cheng,Zhiran Ju,Fen-Er Chen
Isavuconazole, a clinically important triazole antifungal drug, relies on α-hydroxymethyl ketone as a key synthetic precursor. Here, we present a novel chemo-enzymatic approach for the synthesis of isavuconazole. Using 2,5-difluorobenzaldehyde as the starting material, engineered benzaldehyde lyase (BAL) catalyzes the crucial benzoin reaction to form the key intermediate α-hydroxymethyl ketone. Notably, this biocatalytic process operates without extra cofactors (thiamine pyrophosphate, ThDP) and Mg2+, achieving a time-space yield (TSY) of 17.2 g·L–1·day–1 under optimized conditions. After further chemical reactions on the intermediate, isavuconazole is obtained through an eco-friendly process that outshines traditional chemical synthesis. This optimized protocol is efficient and scalable, yielding isavuconazole at 28.9%, double that of the current industrial chemical process (14.2%), highlighting the remarkable advantages of enzyme-catalyzed synthesis.
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Journal of Materials Chemistry C
·
2025
·Vol. 13
·期 38
·19626-19634
·
IF 5.1
Yunxiao Min,Jie Liu,Zihan Wang,Liang Li
Low-dimensional materials, particularly quasi-2D semiconductors like bismuth oxychalcogenides (BiOX), offer unique advantages for advanced photodetection due to van der Waals integration and quantum-confined properties. In this research, Bi2TeO5 nanosheets were successfully grown using a chemical vapor deposition method. The resulting Bi2TeO5 photodetector exhibited remarkable performance characteristics. Specifically, it demonstrated an open circuit voltage of −1.14 V, a depolarization field of 5.7 × 107 V m−1, a remarkably low dark current of 10−15 A, an impressive on/off ratio of 103, a responsivity of 466.80 mA W−1, a detectivity of 4.23 × 1012 Jones, and an EQE of 218.44% at 8 V bias. The work highlights the significant potential of Bi2TeO5 and provides new design strategies for developing next-generation 2D photodetectors.
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CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Kewei Shu,Wenjuan Li,Yi Zhang,Yan Zong,Huilan Li,Yu Wang,Zixiong Sun
Flexible, miniature, and lightweight supercapacitor is ideal power source for next-generation portable and wearable electronics. However, their widespread application is limited by a critical drawback, self-discharge, which leads to energy loss during idle periods. To this end, a polyvinylidene fluoride (PVDF)-based nanofiber separator with piezoelectric properties that can effectively suppress self-discharge in supercapacitors, was prepared via electrospinning. By incorporating hydrophilic cellulose acetate (CA) and reduced graphene oxide (rGO) into the PVDF matrix, both the electrolyte affinity and piezoelectric output of the separator are significantly enhanced. The resulting rGO/CA/PVDF composite membrane exhibits outstanding mechanical flexibility, high porosity, excellent electrolyte uptake, making it highly suitable separator for flexible supercapacitor. Supercapacitors equipped with such separator exhibit superior electrochemical performance with a specific capacitance of 178.2 F/g at 10 A/g. Notably, an impressive capacitance retention of 79 % was achieved after 24 h of self-discharge test. The reduction in self-discharge is primarily due to the limited diffusion of electrolyte ions, induced by the polarized rGO/CA/PVDF composite separator endowed with improved piezoelectric characteristics. This work highlights the potential of piezoelectric separators as an effective strategy for long-term energy retention, and offers new insights into the rational design of functional separators with self-discharge mitigation capabilities.
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JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Lei Cao,Yu Sun,Hongpeng Liu,Huiming Lin,Lingfei Li
The efficient separation of emulsified oily wastewater was of significant practical importance. However, it was hindered by factors such as low separation flux and severe membrane fouling, making the separation process highly challenging. Inspired by the in-situ nanocomposite strategy mediated by bionic mussel adhesion, this study used oxidants to induce rapid deposition of dopamine (DA) and fulvic acid (FA) on the polyvinylidene fluoride (PVDF). Combined with in-situ growth technology, ZIF-8 nanoparticles were anchored on the coating surface to construct a PVDF-based composite membrane with heterogeneous wettability structure was constructed which were composed of lipophilic ZIF-8 protrusions, hydrophilic layer, and PVDF basement membrane. In the process of separating oil-bearing lotion, the raised ZIF-8 helps to capture and collect oil droplets, and works in synergy with the screening effect of the hydrophilic layer. The demulsification capability was enhanced by the unbalanced force derived from the wettability discrepancy between the protrusions and the substrate, thus enabling efficient separation of emulsions. The optimized composite membrane efficiently separates light/heavy emulsions, with a rejection rate exceeding 99.4 %. The n-hexane-in-water emulsion maintained a high recovery flux ( FRR ) of 92.3 % after 30 cycles. Molecular dynamics simulations confirm that the membrane's hydrophobic/hydrophilic architecture actively promotes emulsion demulsification and oil droplet separation. This study provides precious view into the design of emulsion separation membranes and advances in separation technologies.
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ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Qi Dai,Xiaojuan Wang,Cai Liu,Zhenzhen Feng,Baosheng Ge,Xiqi Ma,Zhixiong Zhang,Jinyi Yu,Xiaoqiang Wang,Fang Huang
Melanoma, the skin cancer with the highest mortality rate, can be diagnosed at the early stage by detecting unique biomarkers. Over-expressed tyrosinase has been confirmed by dozens of clinical studies as an independent factor to evaluate the malignancy of melanoma. Using Enteromorpha Prolifera as the raw material, herein we develop a novel fluorescent probe , ECDY, which can sensitively detect the tyrosinase activity in different types of cells. More importantly, melanoma cells can be specifically distinguished through cell lysate measurements as well as the whole-cell imaging technique. Mechanically, the tyrosine groups on the surface of ECDY can be specifically recognized by tyrosinase and further converted into dopaquinone, which consequently causes the intramolecular fluorescence quenching of the probe through photoinduced electron transfer (PET). Tyrosinase can be detected within 20 min in the solution, and the detection limit is as low as 0.067 U mL −1 . For the in vitro demonstration, we evaluate the fluorescence decay of ECDY in response to the intracellular tyrosinase activity within the lysate of various cell lines, including non-cancerous, non-melanoma cancerous, and mouse melanoma ones. The experimental results verify that ECDY can accurately measure the apparent tyrosinase activity in different cell lines and detect melanoma cell lysate specifically. The confocal fluorescence imaging experiments further demonstrate that ECDY can distinguish melanoma cells from others significantly. We believe that ECDY provides a new strategy for the efficient detection of tyrosinase and melanoma cells, and is expected to apply as a clinical diagnosis platform.
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