POLYMER BULLETIN
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2015
·Vol. 73
·期 4
·1185-1206
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IF 1.438
Yan Huiqiong,Chen Xiuqiong,Feng Yuhong,Xiang Fei,Li Jiacheng,Shi Zaifeng,Wang Xianghui,Lin Qiang
The objective of this study was to develop a sustained drug release system based on alginate/exfoliated montmorillonite nanocomposite for acetamiprid, a neonicotinoid insecticide, to improve its sustained release performance. Montmorillonite (MMT) was modified with cetyl trimethyl ammonium bromide (CTAB) using a ball-milling method. Then, acetamiprid was immobilized into the modified MMT layers through freeze-drying technology. Subsequently, the drug-loaded alginate-exfoliated MMT composite beads were prepared by dropwise addition of the mixture of the drug-loaded modified MMT and the alginate solution into the calcium chloride and chitosan blended solutions. The structure and surface morphology of the modified MMT and composite materials were determined by the means of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), BET-specific surface area measurements, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) analysis. The experiments on immobilization and release of acetamiprid were performed to examine the effect of the modified MMT on the properties of the composite beads. Experimental results showed the intercalation of CTAB into MMT has been successfully achieved during the ball-milling process, which was beneficial to the formation of exfoliated MMT nanocomposites in alginate matrix. The intensive force supplied during the superfine pulverization of the ball-milling process was effective to increase the modified MMT’s specific surface areas and decrease its particle size, consequently improving the drug-loading rate (DL) and encapsulation efficiency (EE) of the composite beads. The alginate/exfoliated MMT nanocomposite formulation exhibited a slow and sustained release property, which was demonstrated as a promising carrier material to promote the efficient use of organic pesticide, and thereby reduce environmental pollution.
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Journal of Physical Chemistry C
·
2014
·
IF 4.835
Yang Ou,Li-Yang Wang,Liang-Wei Zhu,Ling-Shu Wan,Zhi-Kang Xu
Surface-enhanced Raman scattering (SERS) is an important sustainable technique because of its ability to detect trace-level analytes including pesticides, heavy metals, explosives, proteins, pathogens, and other chemical and biological contaminants. In this paper, we report a facile approach to highly sensitive SERS substrates by combining hierarchically patterned micro- and nanostructures with silver nanoparticles (Ag NPs) adsorbed on poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) surface. The patterned structures were fabricated using breath figures as dynamic templates in which polar block enriches at the rim of the pores. This characteristic of the breath figure method makes it possible to employ a simple coating technique to construct substrates decorated with Ag NPs, which have a diameter mostly ranging from 18 to 30 nm. Results indicate that the hierarchically ordered substrates show enhancement factors as high as 4 × 108. It is also found that the enhancement factors are concentration-dependent, relying on the ratio of the number of analytes to Ag NPs. Moreover, the prominent enhancement at Raman shift of ∼614 cm–1 has been observed, which will be useful in the detection of analytes such as some kinds of pesticides and viruses with characteristic peaks in this Raman shift range (e.g., adenovirus). This proposed approach provides an effective, reproducible, electroless, and facile method for preparing high-quality SERS substrates.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2013
·Vol. 131
·期 4
·
IF 1.395
Xiangli Qiao,Yanming Li
In this study, a highly efficient photo-initiator system was developed, which contained potassium persulfate, N, N, N ′, N ′ -tetramethylethylethylenediamine plus benzil dimethyl ketal. The photo-initiator system could successfully initiate poly (ethylene glycol) dimethyl-acrylate prepolymer to polymerize and crosslink under the irradiation of UV rays, in the presence of concentrated activated sludge, finally leading to the formation of immobilized activate sludge pellet beads. The presence of O 2 and thickness of the reaction solution did not influence the photo-immobilization process. Respiratory measurement result demonstrated that most activated sludge kept alive during the photo-immobilization. Mechanical strength of the immobilized cells could be improved by optimizing contents and ratio of the initiator system. The corresponding mechanism was also discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 39838.
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ENERGY CONVERSION AND MANAGEMENT
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2017
·
IF 5.589
Hao Ying,Li-feng Zhang,Di Wu,Qun-fang Lei,Yong-sheng Guo,Wen-jun Fang
Hyperbranched polyglycerol and acrylic acid were polymerized into smart hydrogel for enzyme immobilization. Lipase from Aspergillus oryzae was selected as model enzyme. Highest enzyme loading amount of 78.93 mg/g and relative enzyme activity of 67.02% were observed. The immobilized enzyme was further used for the synthesis of biodiesel, and the synthesis parameters were optimized with response surface methodology. The yield of fat acid methyl esters (FAMES) under the optimum synthesis condition was determined to be 95.98%. The immobilized enzyme showed good reusability for five consecutive operations without significant loss of FAMES yield. By means of regulating the ionic strength of aqueous solution, the immobilized enzyme was successfully released from the hydrogel. After the enzyme reload, FAMES yield of fresh immobilized enzyme still remained 90% approximately for five consecutive operations. The results demonstrated that the hyperbranched polyglycerol/polyacrylic acid hydrogels could be effectively applied to the enzyme carrier and biodiesel synthesis.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
·
IF 7.7
Mengxin Hu,Hao Zhang,Jian Yang,Bin Lu,Haibing Cao,Zhengbai Cheng,Xiaofeng Lyu,Hongbin Liu,Xingye An
Softness is a crucial criterion in assessing the comfort and usability of tissue paper. Flexible fibers contribute to the softness of the tissue paper by allowing the sheets to conform to the contours of the skin without feeling rough or abrasive. This study focuses on developing innovative CGG/APAM/PDA hydrogels with interpenetrating networks consisting of cationic guar gum, anionic polyacrylamide, and polydopamine for cellulase immobilization, aimed at improving bamboo fiber flexibility. Cellulase biomolecules are efficiently immobilized on CGG/APAM/PDA hydrogels through the Schiff base reaction. Immobilized cellulases have a wider pH applicability than free cellulases, good storage stability, and can maintain high relative activity at relatively high temperatures. The treatment of bamboo fibers with immobilized cellulase results in a significant increase in flexibility, reaching 6.90 × 10 14 N·m 2 , which is 7.18 times higher than that of untreated fibers. The immobilization of cellulases using CGG/APAM/PDA hydrogels as carriers results in a substantial enhancement of storage stability, pH applicability, and inter-fiber bonding strength, as well as the capacity to sustain high relative enzymatic activity at elevated temperatures. The immobilization of cellulase within CGG/APAM/PDA interpenetrating network hydrogels presents a viable strategy for enhancing bamboo fiber flexibility, thereby expanding the accessibility of tissue products.
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PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
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2024
·
IF 7.4
Jian Jia,Mei-Ling Xu,Xiao-Jie Jiang,Li-Na Zhang,Xiao-Lei Lu,Jiang Zhu,Xin Cheng
The utilization of cement-stabilized iron tailings as pavement base necessitates rigorous scrutiny of heavy metal ion leaching, particularly under fluctuating environmental pH conditions. Given the insufficient capacity of cement to stabilize Cr(Ⅵ), this paper explores the integration of defect-engineered metal-organic frameworks (MOFs) as additives in cement-stabilized iron tailings to reduce Cr(Ⅵ) leaching. Results shows that the utilization of MOFs material mitigates Cr(VI) leaching in cement-stabilized iron tailings while enhancing their mechanical properties. The Cr(Ⅵ) leaching from samples with the addition of UiO-66-(OH)₂ and UiO-66-(OH)₂-D exhibited a substantial reduction of 60.2 % and 88.6 %, respectively. The stabilized mechanism is attributed to the strong affinity between Cr(Ⅵ) and hydroxyl groups in MOFs. Furthermore, UiO-66-(OH) 2 -D has a larger pore diameter to expose more hydroxyl groups, which greatly improves its adsorption performance for Cr(Ⅵ). Meanwhile, the unconfined compressive strength (UCS), splitting strength and compressive resilience modulus increased by 13.4 %, 35.1 % and 45.7 %, respectively. The mechanisms underlie that the MOFs enhanced the early hydration process and optimized of the pore size distribution within the solidified body. This study presents a viable and efficient approach for the sustained mitigation of Cr(Ⅵ) leaching within cement-stabilized iron tailings.
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Nanomaterials
·
2024
·Vol. 14
·期 4
·340
·
IF 4.4
Xiaozhou Li,Jie Chen,Bin Wu,Zhen Gao,Bingfang He
Exploring an appropriate immobilization approach to enhance catalytic activity and reusability of cellulase is of great importance to reduce the price of enzymes and promote the industrialization of cellulose-derived biochemicals. In this study, Fe3O4magnetic nanoparticles (MNPs) were functionalized with meso-2,3-dimercaptosuccinic acid to introduce carboxyl groups on the surface (DMNPs). Then, melamine–glutaraldehyde dendrimer-like polymers were grafted on DMNPs to increase protein binding sites for the immobilization of processive endoglucanase EG5C-1. Moreover, this dendrimer-like structure was beneficial to protect the conformation of EG5C-1 and facilitate the interaction between substrate and active center. The loading capacity of the functionalized copolymers (MG-DMNPs) for EG5C-1 was about 195 mg/g, where more than 90% of the activity was recovered. Immobilized EG5C-1 exhibited improved thermal stability and increased tolerability over a broad pH range compared with the free one. Additionally, MG-DMNP/EG5C-1 biocomposite maintained approximately 80% of its initial hydrolysis productivity after five cycles of usage using filter paper as the substrate. Our results provided a promising approach for the functionalization of MNPs, enabling the immobilization of cellulases with a high loading capacity and excellent activity recovery.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
·
IF 7.7
Xiaolong Sun,Jiahuan Hu,Yufeng Zhou,Xiangyu Zi,Huayue Zhu,Xi Luo,Yongqian Fu
In this study, we endeavored to catalyze the biosynthesis of D -phenyllactic (D-PLA) from L-Phenylalanine (L-Phe) through a one-pot method. However, the crucial enzymes for the biosynthesis of phenylpyruvate (PPA), amino acid oxidase (L-AAD), is a membrane-bound protein. Herein, we proposed a novel co-immobilization strategy of whole cells and enzymes, integrating them into ZIF-90 to achieve efficient biosynthesis of D-PLA. Consequently, we embarked on integrating both enzyme and E. coli into ZIF-90, ultimately obtaining the novel biocatalyst E. coli /LDH@ZIF-90. This achievement facilitated the cascade reaction between LDH and E. coli , enabling a streamlined one-pot bioconversion process. The morphology and structure of E. coli /LDH@ZIF-90 were thoroughly characterized using a range of methods, including XRD, SEM, FT-IR, CLSM, and XPS, which confirmed that the material had been successfully synthesized. Further activity experiments revealed that E. coli /LDH@ZIF-90 exhibited good stability even under harsh conditions. Additionally, the biocatalyst retained 76 % of its initial catalytic activity after completing six cycles. Moreover, when utilized for the biosynthesis of D-PLA, this system demonstrated an impressive conversion rate of 85.2 % after 12 h. The successful cascade catalysis from L-Phe to D-PLA underscored the potential of the enzyme-cell cascade catalytic system, offering valuable insights for its potential industrial applications.
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BIOSENSORS & BIOELECTRONICS
·
2013
·
IF 5.437
Yi Huang,Wen Wang,Zou Li,Xiaoli Qin,Lijuan Bu,Zhiyong Tang,Yingchun Fu,Ming Ma,Qingji Xie,Shouzhuo Yao,Jiming Hu
We report here on a facile enzymatic polymerization protocol to prepare enzyme—poly(thiophene-3-boronic acid) (PTBA) polymeric biocomposites (PBCs) for high-performance mono-/bi-enzyme amperometric biosensing. Horseradish peroxidase (HRP)-catalyzed polymerization of thiophene-3-boronic acid (TBA) monomer was conducted in aqueous solution containing HRP (or plus glucose oxidase (GOx)) by either directly added or GO x -glucose generated oxidant H 2 O 2 . The mono-/bi-enzyme amperometric biosensors were prepared simply by casting the dialysis-isolated PBCs on Au-plated Au electrode (Au plate /Au), followed by coating with an outer-layer chitosan (CS) film. The boronic acid residues are capable of covalent bonding with enzyme at the glycosyl sites (boronic acid-diols interaction), which should less affect the enzymatic activity as compared with the common cases of covalent bonding at the peptide chains, and UV–vis spectrophotometric tests confirmed that the encapsulated HRP almost possesses its pristine enzymatic specific activity. The enzyme electrodes were studied by cyclic voltammetry , electrochemical impedance spectroscopy and chronoamperometry in the presence of Fe(CN) 6 4− mediator. The CS/HRP–PTBA/Au plate /Au electrode responded linearly to H 2 O 2 concentration from 1 to 300 μM with a sensitivity of 390 μA mM −1 cm −2 and a limit of detection (LOD) of 0.1 μM. The bienzyme CS/GO x −HRP−PTBA(H 2 O 2 )/Au plate /Au electrode responded linearly to glucose concentration from 5 μM to 0.83 mM with a sensitivity of 75.1 μA mM −1 cm −2 and a LOD of 1 μM, and it is found here that the use of Fe(CN) 6 4− that can only efficiently mediate HRP favorably avoids the “unusual amperometric responses” observed when other mediators that can efficiently turn over both HRP and GO x are used.
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高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Zhenjie Zheng,Jiarong Lin,Junyi Zhang,Fang Luo,Zuquan Weng,Jian Wang,Cuiying Lin,Bin Qiu,Zhenyu Lin,Hao Lin
Herein, we present the development of an ultra-sensitive immobilization-free homogeneous electrochemiluminescence (ECL) biosensor, leveraging the electrostatic repulsion between a negatively charged indium tin oxide (ITO) electrode and DNA and exonuclease I (Exo I)-powered signal amplification, to achieve highly efficient detection of thrombin. Specifically, the aptamer and the complementary DNA engage in the formation of a double-stranded DNA (dsDNA) complex. This negatively charged dsDNA structure subsequently associates with a positively charged ECL indicator, namely ruthenium phenanthroline (Ru(phen) 3 2+ ), resulting in the generation of the dsDNA-Ru(phen) 3 2+ ECL probe. The negatively charged dsDNA-Ru(phen) 3 2+ experiences electrostatic repulsion from the negatively charged ITO electrode, resulting in a low ECL signal. Nonetheless, upon the addition of thrombin, the aptamer preferentially binds to thrombin, triggering the releases of the embedded Ru(phen) 3 2+ facilitated by Exo I and hence resulting in a robust and enhanced ECL signal. The amplified ECL signal is linearly correlated with the logarithm of thrombin concentration within a detection range spanning from 10 fmol/mL to 50 pmol/mL, with a remarkable detection limit of 3.21 fmol/mL. This strategy eliminates the need for cumbersome labeling steps, avoids the electrode modification process, overcoming the low immobilization efficiency of aptamers and poor signal transduction of indicators labeled at the end of DNA.
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CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Pan Wang,Zhen Teng,Sifan Zeng,Chen Chen,Wanlin Feng,Xiaosong Zhou
In this study, granite wastes based glass-ceramics containing Eu 2 O 3 as simulated radionuclides is successfully synthesized via solid-state sintering method. The structure, mechanical properties and chemical durability are deeply investigated. The main phase in this glass-ceramics is oxyapatite (Ca 2 Eu 8 (SiO 4 ) 6 O 2 ), which is dispersed homogenously in glass matrix. The density dominates the properties of Vickers hardness and bending strength . The glass-ceramics containing 40 wt % of Eu 2 O 3 has the optimal mechanical properties, with the Vickers hardness , bending strength and density of 5.12 GPa, 79.44 MPa and 98.77 %, respectively. The 28 days leaching experiments show that the glass-ceramics containing 40 wt % of Eu 2 O 3 possess excellent chemical durability. The leaching rate of Al 3+ , Si 4+ , Fe 3+ , Ca 2+ , Eu 3+ are 2.3 × 10 −4 g m −2 d −1 , 6.0 × 10 −4 g m −2 d −1 , 1.2 × 10 −7 g m −2 d −1 , 1.4 × 10 −4 g m −2 d −1 , 3.6 × 10 −8 g m −2 d −1 , respectively. This study indicates that granite wastes based glass-ceramics have excellent chemical stability and mechanical properties, which provides a novel idea for the immobilization of radioactive wastes .
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Materials Today Chemistry
·
2025
·
IF 6.7
Liuqin Zhang,Huali Li,Gege Zhang,Qiuping Li,Fa-Qian Liu
Marine biofouling can cause economic, environmental and safety issues. Here the Cu-MOF/SiO 2 aerogel@PDMS coatings were prepared to prevent the colonization of fouling organisms. The Cu-MOF-74 which can continuously provide copper ions was successfully synthesized through a simple method. SiO 2 aerogel was employed to immobilize Cu ions (Cu-MOF) by the formation of - Si - O -Cu- O -, thereby achieving the goal of more stable release of copper ions from the coating. And the improvement of coating hydrophobicity also helps to enhance the stability of MOFs. The Cu-MOF/SiO 2 aerogel@PDMS coating exhibits significant long-term antibacterial performance, with a maximum antibacterial rate of 99.5 %. And it can enhanced the long-term static anti-biofouling performance of PDMS in the local sea by effectively preventing the colonization of macrofouling organisms (e.g. barnacles, calcareous tubeworms).
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