BIOCHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 3.9
Peng-Cheng Chen,Yao-Dan Zhang,Pu Zheng,Ruo-Xi Sun,Dan Wu
The efficiency of multi-enzyme immobilization is often influenced by the carrier and immobilization techniques employed. In this work, we proposed a ternary enzyme cascade reaction system composed of β-glucosidase (β-G), glucose oxidase (GOD) and horseradish peroxidase (HRP). CaCO 3 microspheres served as a template for in situ immobilization, while poly (allylamine hydrochloride) (PAH) and sodium poly (4-styrene sulfonate) (PSS) were utilized to create PAH-CaCO 3 and PSS-CaCO 3 templates for layer-by-layer multi-enzyme immobilization. The effects of template structure, glutaraldehyde (GA) addition, ethylenediaminetetraacetic acid (EDTA) concentration, and the structure of layer-by-layer assembly were systematically investigated. Our results indicated that an assembly of PSS-CaCO 3 --PAH--β-G--HRP--GOD presented simultaneous high enzyme loading and relative activity. The loadings of β-G, GOD and HRP were 75.2 ± 2.0%, 87.7 ± 4.4% and 85.5 ± 3.2%, respectively, while the relative activities were 81.8 ± 2.7%, 93.6 ± 4.7% and 90.6 ± 3.1%, respectively. Kinetic parameters confirmed that the reaction rate of the immobilized ternary enzymes in this assembly was close to that of the free enzymes. This work provides insights for constructing other multi-enzyme cascade reaction systems using immobilization techniques.
✓ 已验证
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2023
·
IF 4.1
Quan Chen,Xiangmei Cheng,ShengSheng Liu,Dichen Xia,Yan Liu,Zhen Zhang,Pengcheng Gu
Biochar materials with low cost and desired properties have gradually been widely applied in multitudinous domains, especially in radioactive wastewater remediation. Multi-heteroatom doping is a useful method for the design of doping biochar with uranium immobilization of excellent performance. Herein, multi-heteroatom self-doped microporous carbon was designed and synthesized via extraction and carbonization of collagen by potassium compound assisted, which was extracted by low-cost fish scales as the precursor and tested for high-performance uranium immobilization . The multi-heteroatom self-doped biochar exhibited the maximum saturated adsorption capacity of 142.06 mg/g for U(VI) at pH = 5, reflecting the significant increase in available adsorption sites from multi-heteroatom doped. The strong complexation process was proposed for the mutual effect between U(VI) and multi-heteroatom doped biochar, where abundant functional groups (oxygen and amino) and sulfur metal sites groups were the primary active sites. The design of multi-heteroatom self-doped biochar provided a universal and effective method for purifying U(VI) from wastewater systems.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Zhangyi Huang,Wanying Guo,Yang Shi,Ruichong Chen,Zhijun Wang,Yutong Zhang,Junjing Duan,Jianqi Qi,Haomin Wang
The Gd 2 Zr 2 O 7 (GZO)-based ceramic waste form exhibits promising potential for radioactive waste immobilization. However, the isomorphic immobilization capacity and irradiation effects of GZO-based ceramic waste forms with varying waste loads remain inadequately understood. This study employed a facile combustion method to synthesize ceramic powders and utilized conventional sintering with a relatively short dwelling time to fabricate GZO-based ceramic waste forms. We investigated the isomorphic immobilization behavior and He ion irradiation effects of the synthesized waste forms. The outcomes demonstrate that GZO effectively immobilizes simulated waste composed of 11 types of oxides, achieving a waste load as high as 50 wt% with a single pyrochlore phase and homogeneous element distribution. Under He + irradiation, aggravated structural degradations, including exacerbated lattice swelling, increased amorphization degree, and premature He bubble chain/microcrack formation, were observed in GZO-based waste forms with an increasing waste load.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Haizhi Zhang,Zhiping Sun,Cunhui Wu,Xinguang Qin,Gang Liu
The immobilization strategy between ZIF-8 and different enzymes has focused on in situ encapsulation and pore infiltration, while the surface attachment has been seldom reported because of less functional groups on the ZIF-8 surface. Here, a magnetic amine-functionalized ZIF-8 with hierarchical pores was designed for efficient covalent immobilization of α-amylase (α-Amy). By using Fe3O4 nanoparticles as the core and ZIF-8 as the shell, followed by Au3+–Zn2+ exchange reaction and β-mercaptoethylamine modification, the magnetic hollow ZIF-8 nanoparticle with amine groups on the surface was synthesized. With the assistance of glutaraldehyde, an α-Amy-magnetic hollow ZIF-8 composite was prepared and fully characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy element mapping analysis, and vibration sample magnetometry. Then, the catalytic activity of immobilized α-Amy was explored with a Km of 2.307 mg/mL and Vmax of 0.506 mg/mL·min, indicating excellent catalytic activity. The study about stability and reusability demonstrated that the catalytic activity of immobilized α-Amy remained above 50% after 10 times of reuse. Thus, the designed magnetic amine-functionalized ZIF-8 was verified to be a nice carrier for covalent enzyme immobilization.
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN NUCLEAR ENERGY
·
2023
·
IF 2.7
Qiuyu Zheng,Xiaofeng Zhao,Yang Liu,Yuancheng Teng,Yuxiang Li,Guangyuan Liu,Xiayu Zheng,Wei Luo,Rajeev Ahuja
Rhabdophane LnPO 4 ·0.667H 2 O (Ln = La to Dy) is an important precipitation-enrichment barrier to isolate actinides from groundwater. However, the bearing capacity of different actinides in rhabdophane has been poorly understood due to the complex coordination environment induced by water molecules. In this work, the precipitation behaviors of Nd x Sm x La 1-2 x PO 4 ·0.667H 2 O ( x = 0.1–0.5) solid solutions are systematically investigated to understand the simulated actinides occupancy and the chemical precipitation processes. The results show that Nd 3+ and Sm 3+ can be removed over 99% after 12 h in an approximate pH = 1 solution. Nd x Sm x La 1-2 x PO 4 ·0.667H 2 O single-phase has been observed by refined XRD , although the composition distribution of nanograins is extremely uneven. The distribution of simulated actinides can be homogeneous after prolonging reaction time to 12 days or sintering temperature over 1000 °C. Both Nd 3+ and Sm 3+ are preferentially incorporated on non-hydrated lattice sites when x ≤ 0.1. Besides, the chemical stability of La 0.332 Nd 0.334 Sm 0.334 PO 4 ·0.667H 2 O rhabdophane is compared with associated monazite to understand the leaching activities of simulated actinides incorporated on hydrated and non-hydrated sites. The leaching rates of monazite are smaller than that of rhabdophane, suggesting that [LnO 9 ] polyhedrons in monazite have a stronger energy threshold than [LnO 8 ] and [LnO 8 ⋅H 2 O] polyhedrons in rhabdophane.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Wenhua Tong,Xinhang Du,Jiepeng Wang,Hao Yan,Tonghui Xie,Yabo Wang,Yongkui Zhang
Organophosphate esters (OPEs) waste is difficult to dispose effectively because of its stability and the potential risk of P element. In this study, taking one typical organic extractant of tributyl phosphate (TBP) as an example, we proposed a strategy to treat OPEs inspired by chemical looping combustion (CLC) technology—oxygen carrier immobilization process (OCIP), aiming at efficient TBP degradation and simultaneous P immobilization. Adopting Fe-Mn bimetallic oxide (FMBO) as oxygen carrier, an almost 100% P immobilization efficiency was achieved under recommended conditions which were obtained by response surface methodology . Meanwhile, gaseous products released from TBP degradation, e.g., non-methane hydrocarbon, was lower than the maximum allowable emission concentration limit. Further characterizations implied that P-species released from reaction process were mainly immobilized as stable inorganic forms of metaphosphate, phosphate and pyrophosphate. On the basis of identifying degradation intermediates, we proposed a possible degradation pathways. FMBO as an oxygen carrier provided sufficient oxygen molecules for flameless combustion of OCIP process. Electron paramagnetic resonance measurement confirmed the existence of oxygen vacancies on FMBO surface, which contributed to the formation of •O 2 − . Oxidation by oxygen molecules and •O 2 − attack resulted in the degradation and mineralization of TBP, with simultaneously achieving P stabilization.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 6
·4191-4204
·
IF 3.917
Cheng Deshan,Bai Xue,He Mantang,Wu Jihong,Yang Hongjun,Ran Jianhua,Cai Guangming,Wang Xin
Depositing anisotropic noble metal nanoparticles with high uniformity and yield on flexible substrates is the determining factor for surface enhanced Raman spectroscopy (SERS) detection. In this work, flexible, durable and sensitive SERS substrates were fabricated by in situ reduction of Ag nanoparticles on polydopamine templated cotton fabrics (CF) as catalytic hotspots to enhance the following deposition of Au nanoparticles. The coated CF were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy and X-ray diffraction to understand the surface morphology, chemical composition and crystalline structure, respectively. The SEM images indicate that the nanoparticles are dispersed evenly on the CF. 4-Mercaptobenzoic acid (4-MBA) has been used as the probe molecule to evaluate the sensitive and reproducible SERS properties of the as-fabricated SERS substrate. The as-prepared SERS substrates were demonstrated to detect carbaryl pesticides on a cucumber, and carbaryl with the concentration of as low as 10 −6 M (0.20 ppm) could be detected to ensure food safety.
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2019
·
IF 4.914
Jingqing Tian,Haocheng Li,Xin Zeng,Zichun Wang,Jun Huang,Chen Zhao
ABSTRACT Development of dry reforming of methane and carbon dioxide is an effective route to convert in-dustrial waste gases such as coke-oven gas and coal-to-oil gas into platform syngas. However, this process encounters severe problems of metal particle sintering and coke formation at high tem-peratures. In this work, we developed a new synthetic method for preparing confined Ni/MCM-41 catalysts, which impede the sintering of metal nanoparticles (NPs) and coke deposition at high temperatures, enabling them to be successfully applied to methane dry reforming . The method results in high activity and stability of the catalyst at 700 °C for 200 h. The Ni precursor is immersed in ethanol and impregnated into MCM-41 by the peculiar capillary action of hexagonal straight mesopores . By this method, 10 wt% Ni NPs (d = 2 nm) is equably confined to the mesoporous channels with strong metal-support interactions, as confirmed by HRTEM, TEM mapping, H2-TPR, and XRD measurements. Such a confined structure has a significant effect on the inhibition of metal NP agglomeration and carbon deposition during methane dry reforming, as evidenced by TEM, Raman, TGA, and TPO measurements of used Ni/MCM-41 catalysts. In contrast, unconfined Ni/MCM-41 catalysts, with Ni NPs located on the pore exteriors, are rapidly deactivated after 12 h due to the blocked contact between the active metal centers and the gas feedstock. Additionally, a fast increase in the Ni NP size and the formation of substantial carbon nanotubes on the unconfined catalyst surface are seen. This work offers a facile approach for the synthesis of anti-sintering, car-bon-resistant confined Ni catalysts that can operate at high temperatures
✓ 已验证
产品关联
DOI
高影响因子
CLAY MINERALS
·
2019
·Vol. 54
·期 3
·293-298
·
IF 1.787
Dong Li,Min Shen,Guofan Sun,Huiran Jin,Peng Cai,Zhihui Wang,Yeling Jin,Jing Chen,Shijie Ding
A Pickering emulsion was prepared via synergistic stabilization of a lipase and palygorskite particles. The optimum conditions for the stabilization of the Pickering emulsion, such as the concentrations of the palygorskite particles and lipase, were explored. The morphology of emulsion droplets was examined using digital optical microscopy and polarizing optical microscopy. The palygorskite–lipase co-stabilized Pickering emulsions were investigated by determination of the adsorption rate, pH and zeta potential of the aqueous dispersion, as well as by determining the contact angle values of the lipase solution on a palygorskite disc that was immersed in toluene. The catalytic performance of the immobilized lipase in the Pickering emulsion was studied via the investigation of its thermal stability, storage stability and reusability. The immobilized lipase showed greater stability than the free lipase. The lipase immobilized by Pickering emulsion retained a high level of activity even after seven periods of recycling.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Zhengwei Zhang,Kun Yan,Ling Zhang,Qian Wang,Ruixin Guo,Zhengyu Yan,Jianqiu Chen
Heavy metal cadmium (Cd) has drawn tremendous comcern due to its rigorous environmental and health hazards. Herein, we have presented an efficient and economical strategy for the removal and recycling of hazardous Cd ions using microalgae cells as the bioreactors. Remarkably, the green bio-platform for the bioproduction of CdSe nanoparticles (NPs) was developed depending on their orderly regulated and sustainable cellular environment. The biofabricated CdSe NPs manifested favorable photoluminescence properties, and presented well monodispersed spherical morphology and certain crystallinity structure with mean size of smaller than 7 nm. Especially, the fluorescence “turn off” sensing system based on the CdSe NPs was established to detect Hg 2+ . The nanosensor enables the quantitative analyses of Hg 2+ with a linear range of 0–2.0 μM and a detection limit of 0.021 μM. Furthermore, it was preliminarily speculated that the reducing biomolecules in the algae cells could be involved in the formation of CdSe NPs. This work not only provides new insights into the removal and recycling of hazardous Cd ions, but also brings a promising route for biosynthesis of CdSe NPs.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2019
·
IF 4.916
Xin Liu,Xudong Zhu,Mohamed Amara Camara,Qishu Qu,Yichu Shan,Li Yang
Immobilized enzyme micro-reactors (IMERs) are of vital importance in developing miniaturized bioanalytical systems and have promising applications in various biomanufacturing. An inherent limitation in designing IMERs is the one-dimensional cylindrical geometry of micro-channels that offers limited exposed surface area for molecular reorganization and enzyme immobilization. In this study, we report a robust capillary-IMER based on a three dimensional porous layer open tubular (3D-PLOT) column which is prepared by an easy-to-control surface modification strategy via single-step in situ biphasic reaction. The 3D-PLOT column with highly uniform porous geometry and narrow distribution of porosity can greatly enhance the surface-area-to-volume ratio of the micro-channels, showing the beneficial effects for enzyme immobilization to enhance reaction efficiency and shorten analysis time. Taking trypsin as a model enzyme, enzymatic activities of immobilized enzyme are analyzed. We compare enzyme assays using the proposed 3D-PLOT-IMER with those using normal capillary-IEMR without surface modification as well as free trypsin. The 3D-PLOT-IMER exhibits excellent stability and inter/intra-day reproducibility, and these characteristics imply the reliability of the proposed IMERs for accurate enzyme assay. The feasibility of the proposed method for potential application in biological analysis is demonstrated by coupling the 3D-PLOT-IMER with a nano-LC-MS/MS system for online digestion of standard proteins, cell extraction and living Hela cells. Our study show that the surface modification with the proposed 3D-porous layer is a simple and efficient approach for enzyme immobilization, and could be widely suitable for different kinds of IMERs.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL GEOLOGY
·
2019
·
IF 3.618
Jing Liu,Runliang Zhu,Qingze Chen,Huijun Zhou,Xiaoliang Liang,Lingya Ma,Steve C. Parker
Naturally occurring semiconducting metal (oxyhydr)oxides (MeO x ) are ubiquitous geosorbents and geocatalysts, regulating the geochemical behaviors of the chemicals in the environment. The interactions between these MeO x and redox-sensitive elements may involve both the photo-catalytic redox reactions and surface adsorption, and the interplay of the two processes, therefore, makes the interactions rather complex and may have unique environmental effects. The complex interactions between Cr (Cr(III) or Cr(VI)) and hematite under simulated sunlight irradiation were systematically studied under different geochemical conditions (pH, light irradiation, beginning Cr species, etc.). The batch experimentals, X-ray photoelectron spectroscopy (XPS), transmitted electron microscopy (TEM), and energy-dispersive spectroscopy (EDS) were used to determine the concentration and distribution of Cr species (Cr(III), Cr(VI), or the sum of the two) in the aqueous and solid phases. Here we found that both the oxidation of Cr(III) and the reduction of Cr(VI) were accelerated by hematite under sunlight irradiation, resulting in the enhanced immobilization of Cr on hematite. The reduction and oxidation efficiencies were pH-dependent and more evident under acidic condition. In the Cr (III) reaction systems, the reactions can be characterized by (1) the adsorption of aqueous Cr(III) (Cr(III) aq ) to hematite surfaces, (2) the oxidation of adsorbed Cr(III) (Cr(III) ad ) to Cr(VI) ad by the photogenerated holes on hematite, i.e., heterogeneous oxidation, (Bargar et al., 1997) the accumulation of Cr(III) ad on hematite enhanced by Cr(VI) ad , and even the formation of Cr-riched precipitation, which was observed by TEM , and (3) the homogeneous oxidation of Cr(III) aq to Cr(VI) aq by the hydroxyl radicals , generating through interaction between O 2 and the photogenerated electrons (more evident under acidic environment, e.g., pH 3). In the Cr(VI) reaction systems, the reduction of Cr(VI) ad by photogenerated electrons from hematite was also noticeable, with the yielded Cr(III) being fixed on the surfaces. Although the reactions in reduction systems were less extensive than those in the oxidation systems, the reduction reactions would reduce the environmental toxicity of Cr species; while in the oxidation systems, inspite of the higher removal efficiency, the oxidation processes actually increased the environmental risk of Cr. Our results clearly show that hematite could either oxidize Cr(III) or reduce Cr(VI), influencing the speciation and immobilization of Cr under sunlight irradiation. In this term, the natural semiconducting MeO x (e.g., hematite) on Earth's surfaces should play a significant role in affecting the environmental behaviors and toxicities of the redox-sensitive elements (e.g., Cr) through adsorption and photo-catalytic redox processes.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）