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《Materials Letters》2007,61(11-12):2393-2397
Three nanorod-amino acid phosphomolybdates (nanorod-AA-PMo12) (HGly)3[PMo12O40]·(Gly)9 (nanorod-Gly-PMo12, 1), (HLys)3[PMo12O40]·(Lys)4·9H2O (nanorod-Lys-PMo12, 2) and (HHis)3[PMo12O40]·(His)3·H2O (nanorod-His-PMo12, 3), were prepared by the solvent-thermo technique, using reverse micelles as a template, and characterized by transmission electron microscopy (TEM), FT-IR spectroscopy, X-ray diffraction (XRD), cyclic voltammetry (CV), elemental analysis and thermogravimetric analysis (TGA). Antibacterial experiments of the nanorod-AA-PMo12 against Escherichia coli indicated remarkable activity. The {nanorod-Gly-PMo12/PEI}n films were also prepared (PEI = polyethyleneimine) and their antibacterial activity was studied which exhibited potential of solid antimicrobial. 相似文献
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In this paper, several kinds of silver supporting activated carbon fibers (ACF-Ag) were prepared by the reduction adsorption
on activated carbon fiber (ACF) activated with steam or H3PO4 using sisal, viscose and pitch fiber as precursors. Their pore structure and surface chemistry were characterized using nitrogen
adsorption, XPS, WXRD and ICP quantitative analysis. Their antibacterial activities were tested. The results showed that metallic
silver particle in micron or nano-scale size could be easily and dispersedly supported onto the surface of ACF using reduction
property of ACF without largely decreasing their specific surface area. The ACF-Ag showed strong antibacterial activity against
Escherichia coli and Staphylococcus aureus. The antibacterial activity has closed relationship with the precursors, the method of activation, silver content and the
specific surface area of the ACFs. Generally, higher silver content and higher specific surface area provide the materials
stronger antibacterial activity. ACF activated with phosphoric acid, due to the presence of certain amount of organic phosphoric
groups on the surface, showed stronger antibacterial activity than those activated with steam. The antibacterial materials
can be easily regenerated without decreasing their antibacterial activity and without releasing large amount of silver from
the solid phase. 相似文献
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载银纳米TiO2抗菌剂的制备及抗菌性能研究 总被引:1,自引:0,他引:1
采用四氯化钛自生晶种水解法制备了纳米TiO2,通过在水解过程中引入硝酸银制得载银纳米TiO2。对载银前后的纳米TiO2进行了XRD和TEM表征。XRD图谱表明,纳米TiO2属于锐钛矿晶型结构,水解过程中加入硝酸银得到纳米TiO2与氯化银的复合体(AgCl/TiO2)。TEM照片显示,纳米TiO2样品为分散较好的20-30nm之间的粒子,而载银后的复合物粒子明显增大,有轻度的团聚发生。采用抑菌环、悬浮液浊度法测定了载银前后纳米TiO2的抗菌性能,结果表明,AgCl/TiO2抗菌材料对金黄色葡萄球菌有明显的抑菌效果,其最小抑菌浓度为750mg/L。达到日本制定的“银等无机抗菌剂自主规格及其抗菌实验法”规定的〈800mg/L指标。 相似文献
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壳聚糖经羧甲基化改性后得到水溶性较高的羧甲基壳聚糖(OCMC),它具有优良的稳定性和抗菌性。对比OCMC在不同溶剂中的溶解度,发现OCMC在2wt%乙酸溶液中的溶解性最好。将OCMC与纳米Ag(AgNPs)复合得到Ag-OCMC复合微粒,采用UV-Vis、FTIR、XPS、TEM、SEM和TG-DTA对Ag-OCMC复合微粒的组成、微观结构和热性能进行表征。以大肠杆菌和金黄色葡萄球菌为模型菌种测试Ag-OCMC复合微粒对革兰氏菌的抗菌性能。结果表明:AgNPs为面心立方晶型,平均粒径为40~50 nm;AgNPs的引入提高了壳聚糖和OCMC的分解温度。Ag-OCMC复合微粒对革兰氏菌的抑菌活性明显高于单一壳聚糖基抗菌剂。 相似文献
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AbstractA carbon monolith with a silver coating was prepared and its antimicrobial behaviour in a flow system was examined. The functional groups on the surface of the carbon monolith were determined by temperature-programmed desorption and Boehm's method, and the point of zero charge was determined by mass titration. The specific surface area was examined by N2 adsorption using the Brunauer, Emmett and Teller (BET) method. As a test for the surface activity, the deposition of silver from an aqueous solution of a silver salt was used. The morphology and structure of the silver coatings were characterized by scanning electron microscopy and x-ray diffraction. The resistance to the attrition of the silver deposited on the carbon monolith was tested. The antimicrobial activity of the carbon monolith with a silver coating was determined using standard microbiological methods. Carbon monolith samples with a silver coating showed good antimicrobial activity against Escherichia coli, Staphylococcus aureus and Candida albicans, and are therefore suitable for water purification, particularly as personal disposable water filters with a limited capacity. 相似文献
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Yingying WEI Lin CHEN Shaoban ZHAO Xuguang LIU Yongzhen YANG Jinglei DU Qiang LI Shiping YU 《材料科学前沿(英文版)》2021,15(2):253
High fluorescence quantum yield (QY), excellent fluorescence stability, and low toxicity are essential for a good cellular imaging fluorescent probe. Green-emissive carbon quantum dots (CQDs) with many advantages, such as unique fluorescence properties, anti-photobleaching, low toxicity, fine biocompatibility and high penetration depth in tissues, have been considered as a potential candidate in cell imaging fluorescent probes. Herein, N, S-codoped green-emissive CQDs (QY= 64.03%) were synthesized by the one-step hydrothermal method, with m-phenylenediamine as the carbon and nitrogen source, and L-cysteine as the nitrogen and sulfur dopant, under the optimum condition of 200 °C reaction for 2 h. Their luminescence was found to originate from the surface state. In light of the satisfactory photobleaching resistance and the low cytotoxicity, CQDs were used as a cell imaging probe for HeLa cell imaging. The results clearly indicate that cells can be labeled with CQDs, which can not only enter the cytoplasm, but also enter the nucleus through the nuclear pore, showing their broad application prospect in the field of cell imaging. 相似文献
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《Journal of Experimental Nanoscience》2013,8(1):239-246
ABSTRACTThe incubation and hydrothermal reaction under alkaline condition of bovine haemoglobin with chloroauric acid were investigated. The products in the supernatant from the centrifuge were found to be gold nanoparticles and carbon dots. Greigite (Fe3S4) was found as a byproduct in the precipitation. In the incubation process, the reduction ability of bovine haemoglobin molecules was activated under alkaline condition (pH ≈ 12), and Au(III) ions underwent progressive reduction to form Au nanoparticles in situ. In the hydrothermal reaction, denatured bovine haemoglobin molecules underwent biomineralisation to form carbon dots and greigite. Photoluminescence was used as a measurement of the energy band bending of as-prepared carbon dots. The effects of the acceptor 4-nitrotoluene and donor N,N-diethylaniline molecules on the photoluminescence intensity imply that oxygen-contained surface groups induce the upward band bending of carbon dots. 相似文献
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Pooja Devi Anupma Thakur Sanjeev K. Bhardwaj Shefali Saini Prachi Rajput Praveen Kumar 《Journal of Materials Science: Materials in Electronics》2018,29(20):17254-17261
Carbon dots (CDs) have emerged out as a potential material amongst the carbon family for a wide range of applications including chemical/biological sensing, photocatalysis, bioimaging, etc. The green synthesis of these CDs from natural sources is gaining the significant interest of peer community for their wide utility. Herein, we present a facile one-step pyrolysis method for CDs synthesis from Aloe-Vera extract, which show bright blue luminescence under UV light with a quantum yield of 12.3%. Further, ex-situ morphological, structural and optical characterizations reveal their high quality and excitation independent emission behavior with the presence of carboxyl, hydroxyl functional groups. Furthermore, these CDs were studied for Fe(III) sensing in water without any surface modifications and assessed for their light activated antibacterial activity against E.Coli and Staphylococcus aureus. 相似文献
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Preparation and antibacterial activity of chitosan microshperes in a solid dispersing system 总被引:1,自引:0,他引:1
Ming Kong Xi-guang Chen Yu-ping Xue Cheng-sheng Liu Le-jun Yu Qiu-xia Ji Dong Su Cha Hyun Jin Park 《Frontiers of Materials Science in China》2008,2(2):214-220
In this study, we investigated the interface contacting inhibition behaviors of chitosan against bacterial in the dispersing
state. For that purpose, chitosan microspheres (CMs) in the dispersing state was prepared by the emulsification cross-linking
method. The CMs had smooth surface and spherical shape with the diameter of about 124 μm. They were stable after sterilization
at 121°C and 150 kPa for 20 min. The CMs had similar antibacterial activity to that of chitosan in the solution form. Their
antibacterial activities increased with the increase of the CM concentration, while decreased with the increase of pH of the
system. It was found that the CMs with the degree of deacetylation (DD) of 63.6% exhibited the highest antibacterial activity,
while the CMs with the DD of 83.7% exerted the lowest antibacterial activity among the three tested samples. 相似文献
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KONG Ming CHEN Xi-guang LIU Cheng-sheng YU Le-jun JI Qiu-xia XUE Yu-ping CHA Dong Su PARK Hyun Jin 《材料科学前沿(英文版)》2008,2(2):214
In this study, we investigated the interface contacting inhibition behaviors of chitosan against bacterial in the dispersing state. For that purpose, chitosan microspheres (CMs) in the dispersing state was prepared by the emulsification cross-linking method. The CMs had smooth surface and spherical shape with the diameter of about 124 ?m. They were stable after sterilization at 121°C and 150 kPa for 20 min. The CMs had similar antibacterial activity to that of chitosan in the solution form. Their antibacterial activities increased with the increase of the CM concentration, while decreased with the increase of pH of the system. It was found that the CMs with the degree of deacetylation (DD) of 63.6% exhibited the highest antibacterial activity, while the CMs with the DD of 83.7% exerted the lowest antibacterial activity among the three tested samples. 相似文献
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碳量子点的制备及与牛血清蛋白的相互作用 总被引:1,自引:0,他引:1
以木炭为碳源,分别采用回流、微波及超声等不同方法制备碳量子点(Carbon quantum dots,CQDs)。比较不同方法的优劣并优化反应条件、考察不同因素对其荧光量子产率的影响。得到最佳制备方法,制得粒径较小的荧光CQDs,用钝化剂PEG2000修饰后,提高其荧光寿命和量子产率。将修饰后的CQDs应用于与牛血清白蛋白(Bovine serum albumin,BSA)的相互作用,采用紫外吸收光谱法和荧光光谱法探讨其相互作用机理。结果表明,经回流法所制CQDs的荧光量子产率最高,其与BSA之间的荧光猝灭为静态猝灭过程。 相似文献
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Mahdieh Farhangi Farzad Kobarfard Arash Mahboubi 《Drug development and industrial pharmacy》2018,44(8):1273-1284
Objective: The objective of this study was to evaluate the effect of lipid structure on physicochemical properties of chitosan-fatty acid nanomicelles and prepare an optimum ciprofloxacin-loaded formulation from these conjugates which could enhance the antibacterial effects of drug against some important pathogens like P. aeruginosa.Significance: Nowadays, resistance in infectious diseases is a growing worldwide concern. Nanocarriers can increase the therapeutic index and consequently reduce the antibiotic resistance. By site-specific delivery of drug, the adverse effects of broad-spectrum antibiotics such as ciprofloxacin would be reduced.Methods: Fatty acid grafted chitosan conjugates were synthetized in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. The effects of fatty acid type (stearic acid, palmitic acid, and linoleic acid) on physicochemical properties of conjugates were investigated. Ciprofloxacin was encapsulated in nanomicelles by thin film hydration method. Also, the preparation process was optimized with a central composite design. The antibacterial effect of optimum formulation against P. aeruginosa, K. pneumoniae, and S. pneumoniae species was determined.Results: All conjugates were synthetized with high yield values and the substitution degrees ranged between 2.13 and 35.46%. Ciprofloxacin was successfully encapsulated in nanomicelles. The optimum formulation showed high drug loading (≈?19%), with particle size of about 260?nm and a sustained release profile of ciprofloxacin. The minimum inhibitory concentrations of ciprofloxacin in optimum formulation against P. aeruginosa and K. pneumoniae species were 4 and 2 times lower in comparison with the free drug, respectively.Conclusions: The antibacterial effect of ciprofloxacin was improved by encapsulation of drug in chitosan nanomicelles. 相似文献
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Z. T. Yao T. Chen H. Y. Li M. S. Xia Y. Ye H. Zheng 《Journal of Materials Science》2013,48(24):8580-8587
A green inorganic antibacterial material was prepared using shell waste as a carrier material loaded with silver. It was characterized and analyzed by X-ray diffraction (XRD), scanning electron microscopy equipped with an energy dispersive spectrometer (EDS), X-ray photoelectronic spectroscopy (XPS) and N2 adsorption isotherms. The antibacterial activity was evaluated using Staphylococcus aureus and Escherichia coli as sensitive indicator strains. The antibacterial mechanism was probed and discussed as well. Silver carbonate was detected in the prepared material through XRD analysis. XPS measurement and EDS analysis also confirmed the loading of silver onto the carrier. The antibacterial test demonstrated that the prepared material had good antibacterial property, especially against E. coli. Based on the silver ion release and pH test, as well as comparatively analyzing the characteristics of carrier material and prepared material, we proposed that the antibacterial mechanism mainly involved the antibacterial activity of silver ion, slightly higher pH value and supplementary photocatalytic antibacterial activity of silver carbonate. 相似文献
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Graphene and carbon quantum dots (GQDs and CQDs) are relatively new nanomaterials that have demonstrated impact in multiple different fields thanks to their unique quantum properties and excellent biocompatibility. Biosensing, analyte detection and monitoring wherein a key feature is coupled molecular recognition and signal transduction, is one such field that is being greatly advanced by the use of GQDs and CQDs. In this review, recent progress on the development of biotransducers and biosensors enabled by the creative use of GQDs and CQDs is reviewed, with special emphasis on how these materials specifically interface with biomolecules to improve overall analyte detection. This review also introduces nano-enabled biotransducers and different biosensing configurations and strategies, as well as highlights key properties of GQDs and CQDs that are pertinent to functional biotransducer design. Following relevant introductory material, the literature is surveyed with emphasis on work performed over the last 5 years. General comments and suggestions to advance the direction and potential of the field are included throughout the review. The strategic purpose is to inspire and guide future investigations into biosensor design for quality and safety, as well as serve as a primer for developing GQD- and CQD-based biosensors. 相似文献