ENZYME AND MICROBIAL TECHNOLOGY
·
2022
·
IF 3.705
Yun-Tao Zhao,Kun Zhang,Jian Zeng,Haowen Yin,Wenjing Zheng,Rui Li,Anzi Ding,Shaohong Chen,You Liu,Wenjin Wu,Zhanxin Jing
Enzyme immobilization technology has a key role in improving the stability of enzyme reaction systems and biocatalyst utilization rates. In this study, polyvinyl alcohol/sodium alginate@Fe 3 O 4 (PVA/SA@Fe 3 O 4 ) magnetic immobilized-enzyme hydrogel beads were prepared. Their structure and morphology were characterized by scanning electron microscopy, surface area and porosity analyses, Fourier transform infrared spectroscopy , X-ray photoelectron spectroscopy and a vibrating sample magnetometer. The capability of PVA/SA@Fe 3 O 4 to adsorb neutral protease was investigated with variations in composition, temperature, pH, stirring speed, enzyme concentration, and crosslinking concentration. The optimal parameters of the immobilization process were determined by response surface methodology (3% neutral protease, 4% crosslinking at 200 rpm, 45 °C and pH 7.2), under which an immobilization rate of 41.98 mg/g was obtained. The thermal stability , acid-base stability, and reusability of the immobilized enzyme were improved significantly. After seven cycles, the immobilized enzyme activity remained at 30.8% that of the initial enzyme activity . The results indicate that the immobilization of NP onto magnetic PVA/SA@Fe 3 O 4 hydrogel beads improves enzyme efficiency, giving this process potential industrial applications.
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PubMed
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-11
·
IF 4.259
Zhou Yang,Yuan Shaofei,Liu Qian,Yan Dandan,Wang Yun,Gao Li,Han Juan,Shi Haifeng
In this paper, an efficient and convenient Fe 3 O 4 /PMG/IDA-Ni 2+ nanoparticles that applied to purify and immobilize his-tagged β-glucosidase was synthesized, in which, Fe 3 O 4 /PMG (poly ( N, N’- methylenebisacrylamide-co-glycidyl methacrylate) core/shell microspheres were synthesized firstly using distillation-precipitation polymerization, then iminodiacetic acid (IDA) was used to open epoxy rings on the shell of microspheres to the combination of Ni 2+ . The gene of β-glucosidase that was from Coptotermes formosanus Shiraki was amplified, cloned into the expression vector pET28a with an N-terminal His-tag, and expressed in E.coli BL21. The nanoparticles showed the same purification efficiency as commercial nickel column which was a frequently used method in the field of purifying his-tagged proteins from crude cell lysates. The results indicated that Fe 3 O 4 /PMG/IDA-Ni 2+ nanoparticles can be considered as an excellent purification material. β-glucosidase was immobilized on the surface of Fe 3 O 4 /PMG/IDA-Ni 2+ to form Fe 3 O 4 /PMG/IDA-β-glucosidase by means of covalent bound with imidazolyl and Ni 2+ . The immobilized β-glucosidase exhibited excellent catalytic activity and stabilities compared with free β-glucosidase. In addition, immobilized β-glucosidase can be recycled for many times and retain more than 65% of the original activity. The materials display enormous potential in the aspect of purifying and immobilizing enzyme.
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PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Man-Ke Zhang,Xiang-Hua Ling,Xiao-Hui Zhang,Guo-Zhi Han
A major deficiency of the traditional Fenton technology in practical application is the production of a large amount of sludge. In this paper, we first synthesized a kind of magnetic alginate/PVA hydrogel microspheres by inverse emulsion method along with coprecipitation method. Through the cross-linking action of iron ions , sodium alginate and polyvinyl alcohol formed a stable interpenetrating network structure, in which the magnetic Fe 3 O 4 nanoparticles were stably wrapped. After drying, a novel alginate/PVA hydrogel-supported magnetic Fe 3 O 4 particles were obtained. FTIR,XRD，SEM and EDS were used to confirm the composition and structure of the composite material. Furthermore, the resultant alginate/PVA hydrogel-supported Fe 3 O 4 particles perform excellent broad-spectrum catalytic activity for Fenton degradation of organic dyes. Especially, compared with the classical Fenton catalyst, the double-crosslinked structure in the alginate/PVA hydrogel endows the magnetic Fe 3 O 4 particles with high stability and recyclability. After reuse for six times, the mass loss of the composite material is only 10 %, which can avoid the generation of iron sludge in Fenton-like reaction to the greatest extent.
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高影响因子
JOURNAL OF POWER SOURCES
·
2013
·
IF 4.675
Yingqiang Huang,Yingju Liu,Zhuohong Yang,Jinliang Jia,Xin Li,Yan Luo,Yueping Fang
A novel yolk/shell Fe 3 O 4 –polydopamine–graphene–Pt (Fe 3 O 4 @PDA/RGO/Pt) nanocomposite is synthesized using polydopamine as a moderate modifier for graphene as well as a coupling agent for the assembly of Pt nanoparticles . The morphology and structure of the as-prepared catalysts are characterized by transmission electron microscopy , X-ray photoelectron spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The detailed formation mechanism of such yolk/shell nanocomposite is discussed. Subsequently, its catalytic activity towards the methanol oxidation is evaluated by cyclic voltammetry , chronoamperometry , electrochemical impedance spectra and CO-stripping voltammetry. Results show that such york/shell Fe 3 O 4 @PDA/RGO/Pt exhibits higher electrochemical activity and stability to methanol oxidation than Pt/graphene, which is not only attributed to the synergetic cocatalytic effect at the heterojunction interfaces between the Pt nanoparticles and the support, but also due to the high immobilization of Pt nanoparticles by the functional groups of polydopamine. In addition, the separation ability of Pt nanoparticles from the nanocomposite by Fe 3 O 4 can decrease the CO poison from free Pt nanoparticles. Therefore, this unique yolk/shell nanocomposite may be suitable for the production of catalysts with low-cost and high activity.
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高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2021
·Vol. 329
·期 1
·253-263
·
IF 1.371
Zhou Weini,Wang Hongqing,Hou Sanying,Wang Shiyv
A magnetic nano-composites Fe 3 O 4 @SiO 2 @MnO 2 were fabricated for efficient removal of Th(IV) from aqueous solutions, and characterized by SEM, TEM, XRD, FT-IR, BET, VSM, TGA and XPS. And the sorption of Th(IV) on Fe 3 O 4 @SiO 2 @MnO 2 were investigated as a function of pH, adsorbent dosage and initial Th(IV) concentration. The results showed that the adsorption maximum was 53.19 mg g −1 for Th(IV) at pH = 3.5 and T = 298 K. In addition, the adsorption kinetics followed the second-order kinetic model, and the adsorption isotherm could be perfectly depicted by the Langmuir model. Finally, XPS analysis illustrated that the lattice oxygen (M–O) and the surface hydroxyl oxygen (M–OH) participated in adsorption. In brief, the Fe 3 O 4 @SiO 2 @MnO 2 material could efficiently eliminate Th(IV) from aqueous solutions, which might become a promising material for adsorbing Th(IV) from environmental wastewater.
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高影响因子
ANALYTICA CHIMICA ACTA
·
2019
·
IF 5.256
Mingqian Wang,Ying Liang,Zhicheng Zhang,Guohong Ren,Yajun Liu,Shishan Wu,Jian Shen
Novel multifunctional core-shell nanoparticles (NPs) have attracted widespread attention due to their easy-to-modify surface properties and abundant functional groups. This study introduces a facile approach to synthesize Ag@ iron oxide (Fe 3 O 4 ) @C NPs, and modify with amino-poly (ethylene glycol) (PEG)-carboxyl and folate (FA) on the exposed carbon surface to produce high contrast for excellent stability, good biocompatibility, cancer cell targeting, and synergistic treatment. The multi-armed PEG at the edge of Ag@Fe 3 O 4 @C NPs provides the materials an excellent capacity for doxorubicin (DOX) loading. The carbon layer could be used as a photothermal reagent due to its excellent near-infrared (NIR) absorbance capacity, and Fe 3 O 4 was used as a reagent for magnetic resonance (MR) imaging. In vivo combination therapy with this agent was administered in a mouse tumor model, and a remarkable synergistic antitumor effect that is superior to that obtained by monotherapy was achieved. Concerning these features together, these unique multifunctional Ag@Fe 3 O 4 @C-PEG-FA/DOX NPs could be regarded as an attractive nanoplatforms for chemo-photothermal synergistic tumor therapy with dual-modal fluorescence and MR imaging-guided targeting.
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PubMed
高影响因子
Micromachines
·
2021
·Vol. 12
·期 8
·977
·
IF 2.891
Qi Mao,Weixuan Jing,Weizhuo Gao,Zhengying Wei,Bian Tian,Ming Liu,Wei Ren,Zhuangde Jiang
A novel and efficient enzymatic glucose sensor was fabricated based on Fe3O4magnetic nanoparticles (Fe3O4MNPs)-modified urchin-like ZnO nanoflowers (ZnONFs). ZnONFs were hydrothermally synthesizing on a flexible PET substrate. Fe3O4MNPs were deposited on the surface of the ZnONFs by the drop-coating process. The results showed that the urchin-like ZnONFs provided strong support for enzyme adsorption. For Fe3O4MNPs, it significantly promoted the redox electron transfer from the active center of GOx to the ZnO nanoflowers beneath. More importantly, it promoted the hydrolysis of H2O2, the intermediate product of glucose catalytic reaction, and thus improved the electron yield. The sensitivity of the Nafion/GOx/Fe3O4MNPs/ZnONFs/Au/PET sensor was up to 4.52 μA·mM−1·cm−2, which was improved by 7.93 times more than the Nafion/GOx/ZnONFs/Au/PET sensors (0.57 μA·mM−1·cm−2). The detection limit and linear range were also improved. Additionally, the as-fabricated glucose sensors show strong anti-interference performance in the test environment containing organic compounds (such as urea, uric acid, and ascorbic acid) and inorganic salt (for instance, NaCl and KCl). The glucose sensor’s service life was evaluated, and it can still maintain about 80% detection performance when it was reused about 20 times. Compared with other existing sensors, the as-fabricated glucose sensor exhibits an ultrahigh sensitivity and wide detection range. In addition, the introduction of Fe3O4MNPs optimized the catalytic efficiency from the perspective of the reaction mechanism and provided potential ideas for improving the performance of other enzymatic biosensors.Keywords:enzymatic glucose sensor;Fe3O4magnetic nanoparticles;ZnO nanoflowers;enzyme;electrochemical sensor
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高影响因子
Desalination and Water Treatment
·
2014
·
IF 0.987
Shuhua Zhong,Huaili Sha,Yu He,Gongwu Song
In this work, tobermorite/SiO2/Fe3O4 composites were designed and synthesized by hydrothermal method for the treatment of phosphorus in wastewater. The composites were characterized by scanning electron microscopy and X-ray diffraction. The removal efficiency of phosphorus on the tobermorite/SiO2/Fe3O4 composites was carried out and investigated under various conditions, such as contact time, sorbent content, and pH. After the multi-run experiments, the phosphorous elimination of the tobermorite/SiO2/Fe3O4 composites was declined slightly comparing with the first-run experiments. Compared with the conventional crystallization methods, tobermorite/SiO2/Fe3O4 composites not only gave high efficiency to remove phosphorus from wastewater without any complicated pretreatment, but also provided excellent magnetic properties for separating the phosphorus from water, which made it easy recycled. Moreover, tobermorite/SiO2/Fe3O4 composites had excellent P-elimination properties even in the strong acidic or basic conditions. Therefore, tobermorite/SiO2/Fe3O4 composites were important candidate for water quality control and protection.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 25
·10352-10358
·
IF 3.288
Danlin Bu,Na Li,Yu Zhou,Hengyu Feng,Fei Yu,Chunxia Cheng,Ming Li,Linghan Xiao,Yuhui Ao
N-Halamine-based antibacterial materials are widely used due to their excellent characteristics. However, the N–Cl bonds in N-halamine-based materials are not stable under UV light irradiation so that they are difficult to recover and reuse. Here, a kind of N-halamine-immobilized Fe3O4@SiO2@TiO2(F@S@T-Cl) nanoparticles were prepared. In addition, the UV stability and regeneration capacity were also studied after variable time exposure to UV light. The results showed that nanoparticles have great antibacterial properties against Staphylococcus aureus and Escherichia coli. Meanwhile, the N–Cl bond in the nanocomposite showed outstanding storage stability under UV light irradiation and good regeneration ability; the material can realize cyclic utilization and solve the problem of secondary pollution of the antibacterial material. It provides a broader application prospect for the recyclable N-halamine antibacterial material.
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高影响因子
RUSSIAN JOURNAL OF APPLIED CHEMISTRY
·
2021
·Vol. 94
·期 8
·1066-1071
·
IF 0.85
Vorobyova E. V.
Abstract The effect of fillers, metal oxide nanoparticles (Fe 3 O 4 , ZnO), on the thermal oxidation resistance of polyethylene inhibited by the phenolic antioxidant Irganox 1010 was studied. The distribution of nanoparticles in the polymer matrix was carried out by ultrasound, and the samples were formed by thermal pressing. Thermal oxidation resistance was determined by the duration of the induction oxidation period of film samples. It is shown that the pressure of the press during the formation of the material has a significant effect on the thermal oxidation resistance of the inhibited composite, both filled with nanoparticles of Fe 3 O 4 , ZnO, and unfilled. The nature of the effect of the concentration of the nanofiller on the thermal oxidation resistance of the samples depends on the metal oxide used. An increase in the concentration of the filler Fe 3 O 4 leads to a decrease in the thermal oxidation resistance of the polymer; when using ZnO, this dependence is inverse. The oxidation of the prepared nanocomposite film samples formed under high pressure conditions revealed synergistic effects of nanofillers and antioxidants.
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高影响因子
JOURNAL OF BIOMATERIALS APPLICATIONS
·
2016
·
IF 1.988
Xiali Zhu,Heqing Huang,Yingjie Zhang,Huijuan Zhang,Lin Hou,Zhenzhong Zhang
Safe and efficient drug delivery in a controllable fashion, especially remote and repeatable switch of on-demand drug release, is the subject of widespread attention. A kind of magnetic nanoparticles (DOX-Cit/CuS@Fe3O4-NPs) simultaneously consisted of Cit/CuS@Fe3O4 and doxorubicin (DOX) was presented. The drug release from DOX-Cit/CuS@Fe3O4-NPs could be successfully triggered by the presence of gelatinase, showing great promise for tumor-targeted drug release through an enzymatic degradation mechanism. Compared with free DOX, DOX-Cit/CuS@Fe3O4-NPs could not only specially deliver Cit/CuS@Fe3O4 and DOX into MCF-7 cells, but also could greatly improve the quantity of ROS produced in MCF-7 cells under of 980 nm laser irradiation. DOX-Cit/CuS@Fe3O4-NPs also had highly selective accumulation at tumor tissue of S180 tumor-bearing mice, which were along with a magnet near the tumor site. Furthermore, when combined with NIR laser irridation, DOX-Cit/CuS@Fe3O4-NPs showed a higher antitumor efficacy than the individual therapies in vitro and in vivo. This study showed that DOX-Cit/CuS@Fe3O4-NPs could be used as a platform for tumor chemotherapy, photothermal and photodynamic therapy.
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PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Xuewu Liu,Xingfei Li,Yuxiang Bai,Xing Zhou,Long Chen,Chao Qiu,Cheng Lu,Zhengyu Jin,Jie Long,Zhengjun Xie
This study presents a simple method to immobilize β-agarase onto amino-modified magnetic nanoparticles (MNPs) by biotin/streptavidin (BT/SA) recognition. The effect of BT functionalized with different lengths of poly(ethylene glycol) (PEG) on the activity and stability of heterogeneous biocatalysts was also investigated. The results showed that the enzymatic activity was retained above 93% under the immobilization conditions (pH 7.0, 25 °C, 6 h, and β-agarase concentration of 1 mg/mL). The optimal pH and temperature for both free and immobilized β-agarases were 7 and 30 °C, respectively. PEG length played an important role in the catalytic performance of the immobilized enzyme. As the PEG length increased, an increased trend in activity retention and yield of neoagarobiose was observed. Ultimately, the introduction of PEG24 improved the activity retention of immobilized β-agarase up to 135.67%, and retained 84.18 and 37.04% of residual activity after incubation for 6 h at 40 and 45 °C, respectively, while only 30.50 and 0% of residual activities were observed for free β-agarase at these temperatures, indicating the significantly enhanced stability of the β-agarase after immobilization. Additionally, β-agarase-BTPEG24-SA@MNPs showed the highest yield of neoagarobiose at 45 °C, which was 1.89-fold higher than that of the free enzyme. These results indicated that immobilization of β-agarase on BTPEG-SA@MNPs improved both the catalytic efficiency and stability of the enzyme, thereby promoting the continuous production of neoagarobiose.
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高影响因子
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