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Highly Sensitive and Selective Nanogap-Enhanced SERS Sensing Platform
摘要： This paper reports a highly sensitive and selective surface-enhanced Raman spectroscopy (SERS) sensing platform. We used a simple fabrication method to generate plasmonic hotspots through a direct maskless plasma etching of a polymer surface and the surface tension-driven assembly of high aspect ratio Ag/polymer nanopillars. These collapsed plasmonic nanopillars produced an enhanced near-field interaction via coupled localized surface plasmon resonance. The high density of the small nanogaps yielded a high plasmonic detection performance, with an average SERS enhancement factor of 1.5 × 107. More importantly, we demonstrated that the encapsulation of plasmonic nanostructures within nanofiltration membranes allowed the selective filtration of small molecules based on the degree of membrane swelling in organic solvents and molecular size. Nanofiltration membrane-encapsulated SERS substrates do not require pretreatments. Therefore, they provide a simple and fast detection of toxic molecules using portable Raman spectroscopy.
关键词： hotspots,sensors,molecular filtration,surface-enhanced Raman spectroscopy,localized surface plasmon resonance
更新于2025-11-14 15:30:11
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Determination of filtration and consolidation properties of protein crystal suspensions using analytical photocentrifuges with low volume samples
摘要： Proteins and in particular pharmaceutical proteins like monoclonal antibodies are expensive products. Protein crystallization is an interesting alternative process step to the common purification and formulation of such proteins. The solid-liquid separation of proteins however, is a challenging task because the proteins are sensitive to mechanical stress, which could lead to crystal breakage and often are only available in small amounts for research and development. In this study a newly developed filtration cell for the LUMiSizer ? centrifuge is used to analyze the filtration behavior with low volume samples. Isometric and needle shaped lysozyme crystals serve as model protein crystals. The needle shaped crystals showed about twice as high compressibility and much higher cake resistance than the isometric lysozyme crystals. After the filtration at maximum pressure in the centrifuge the mean particle diameter decreased compared to the unstressed median diameter. With the filtration cell the cake height and filter cake compression can be monitored in-situ and the filter cake resistance and solid volume content can be calculated with one experiment using 200 to 300 μl sample.
关键词： Centrifugal filtration,Cake filtration,Protein crystals
更新于2025-09-23 15:23:52
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Abiotic reductive deiodination of iodinated organic compounds and X-ray contrast media catalyzed by free corrinoids
摘要： Iodinated X-ray contrast media are known for their stability concerning deiodination in the aquatic environment under aerobic conditions. In this study, we demonstrate the abiotic reductive deiodination of the iodinated contrast media iopromide, iopamidol and diatrizoate in the presence of corrinoids. In addition, triiodinated benzoic acid derivatives with iodine atoms bound at different positions were investigated. Corrinoids like cyanocobalamin (vitamin B12) and dicyanocobinamide served as electron shuttles and as catalysts between the reducing agent (e.g., titanium (III) citrate) and the electron accepting iodinated compound. The concentration decrease of the iodinated compounds followed first-order kinetics with rate constant kobs depending on the iodinated compound. A linear correlation between the rate of iodide release and the corrinoid concentration was observed, with deiodination rates for dicyanocobinamide twice as high as for vitamin B12. Reducing agents with a less negative standard redox potential like dithiothreitol or cysteine caused slower deiodination as the cobalt center was only reduced to its CoII oxidation state. With a temperature increase from 11 to 23 °C, the concentrations of released iodide doubled. A complete deiodination was only observed for the iodinated contrast media but not for structurally similar iodinated benzoic acid derivatives.
关键词： Vitamin B12,X-ray contrast media,Abiotic,Deiodination,Bank filtration,Corrinoids
更新于2025-09-23 15:22:29
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Photocatalytic and Filtration performance study of TiO2/CNTs-Filter for oil particle
摘要： Carbon nanotubes (CNTs) with large aspect ratio and specific surface area have the potential in oil liquid particle filtration and catalysis substrate field. In this work, we synthesized the TiO2/CNTs-filter for removing oil particle. Compared with the CNTs-filter, we found that the TiO2/CNTs-filter has smaller pore sizes, higher specific area. TiO2/CNTs-filter shows the excellent filtration performance which is higher than the high efficiency particulate air (HEPA) filter. In addition, the initial pressure drop of TiO2/CNTs-filter is close to conventional HEPA filter and the raise ratio of pressures drop at equilibrium states is less than conventional HEPA filter. Furthermore, the degradation rate of initial state and saturation state reach to 94.5 and 724 μg cm-2 h-1 in first 20 h respectively. At last, we simply discuss the application the composite filter on filtering cooking fume.
关键词： carbon nanotubes,filtration,composite filter,oil particle,photocatalytic
更新于2025-09-23 15:22:29
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Encapsulation of zinc phthalocyanine into bovine serum albumin aggregates
摘要： Artificial hybridization of molecules with proteins is beneficial for biomedical applications. Herein, we describe a novel method for encapsulation of zinc phthalocyanine (ZnPc) aggregates into bovine serum albumin (BSA) aggregates, but not monomeric BSA. This property is potentially useful for not only photodynamic or photothermal therapy but also development of a novel delivery system for hydrophobic drug molecules.
关键词： Gel-filtration chromatography,Photosensitizer,Aggregation,Bovine serum albumin,Phthalocyanine,Photodynamic therapy
更新于2025-09-23 15:22:29
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[IEEE 2018 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Saint-Petersburg, Russia (2018.11.26-2018.11.30)] 2018 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Calibration of AOTF-Based Stereoscopic Imager for Measuring a Three-Dimensional Structure in Arbitrary Narrow Spectral Bands
摘要： We present a comparison of two methods of geometrical calibration for an acousto-optical stereoscopic spectral imager using a flat calibration target. It is shown that the method using a translation of a test object with a given step provides better accuracy of three-dimensional coordinates measurements with fewer images than the method using arbitrary displacements of the test object.
关键词： acousto-optic image filtration,stereoscopy,3-D visualization,spectral imaging
更新于2025-09-23 15:22:29
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Detection of damage of a filter by visualization of filtration process
摘要： This paper deals with testing of filters on the basis of visualization of filtration process. A filtration material can be damaged by flow of the filtered medium, high pressure drop and long-term adverse conditions. These negative effects can cause extensive damage of the filtration textile and filtration efficiency decreases. The filter can be also fractured during manufacturing, processing or by improper manipulation. A testing of a purposely damaged filtration textile is described in the article. Experiments were performed on the filtration setup which permits an optical entrance to the position where a sample of filter is placed. A laser sheet is directed into this place. Scattered light from seeding particles in front of and behind the filter is captured by a digital camera. Images from the camera are analyzed and the filtration efficiency versus time and also versus position can be obtained. Measuring chain including light scattering theory and measuring of light intensity by a digital camera are also discussed in the article.
关键词： damage detection,optical measurement,filtration,visualization,filtration efficiency
更新于2025-09-23 15:21:21
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Flexible nonvolatile resistive switching memory devices based on Bi<sub>2</sub>Te<sub>3</sub> nanosheets films
摘要： Flexible nonvolatile resistive switching memory is a promising candidate for next generation storage technologies. Exploring new materials is of crucial importance to achieve further performances of flexible nonvolatile resistive switching memory. In this work, topological insulator bismuth telluride (Bi2Te3) nanosheets films were introduced into firstly, a typical sandwich construction of Ag/Bi2Te3/indium tin oxide/polyethylene terephthalate with good flexibility, which exhibits nonvolatile bipolar resistive switching characteristics of operation voltage, good mechanical flexibility, and good storage stability. Furthermore, trap-controlled space charge limited current, thermionic emission are the dominant conduction mechanisms in the carrier transport. This work will provide an opportunity for Bi2Te3 nanosheets to be used in flexible electronics application.
关键词： Resistive switching,Bismuth telluride,Flexible memory,Nonvolatile,Filtration
更新于2025-09-23 15:21:01
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Carbon Nanomaterials for Agri-Food and Environmental Applications || Graphene quantum dot-based nanostructures for water treatment
摘要： Water pollution by organic, inorganic, and microbial species presents a threat to the water supply as well as food safety and security. Graphene quantum dot-derived nanostructures have emerged as potential solutions toward water pollution mitigation. Such materials have been successfully prepared and evaluated for the catalytic removal of organic pollutants such as dyes and emerging pollutants, the adsorption of pollutants, filtration, and disinfection. Incorporation of GQDs in various nanocomposites resulted in the modification of the composite properties and improved the removal efficiencies of different pollutants. Careful control and optimization of the amounts of GQDs incorporated are necessary to ensure a positive influence in the pollutant-removal efficiencies of the different nanocomposites. Despite the promising developments around GQD-based nanostructures, more work still remains in order to ensure the design and utilization of such materials in large-scale applications. Nonetheless, GQD-derived nanostructures have potential as pollution remediation tools, owing to the nontoxicity, biodegradable, and abundant functional groups. However, there is a need to develop optimized synthesis conditions that will yield GQDs that are uniform in terms of size and surface functionalities and also develop synthesis routes that will ensure proper distribution of the GQDs within the nanocomposite matrix. This could contribute to consistency in terms of the reported performances of various GQD-derived nanostructures in water pollution abatement.
关键词： membrane filtration,photocatalysis,Graphene quantum dots,water treatment,adsorption
更新于2025-09-23 15:19:57
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Membrane modification with semiconductor diode laser to reduce membrane biofouling for external MBR system and modelling study
摘要： Membrane biofouling is one of the major problem for membrane-based wastewater treatment. In this study, we used laser technology to modify ultrafiltration polyethersulfone (UP150) membrane in order to decrease membrane biofouling. Semiconductor laser diodes with different wavelengths of 405, 520, and 658 nm and different power density of 1.5, 2.0, 2.5 mW were used to improve membrane structure against biofouling. The pure water permeability (Lp), contact angle, porosity, and the average pore size were determined for pristine and modified membranes. Lp value of the pristine UP150 membrane (1102.0 L/(m2.h.bar)) was higher than modified membrane (19.2 L/(m2.h.bar)). The contact angle values were presented that hydrophilicity was decreased from 75.1° to 61.2° for 2 h at 2.5 mW laser irradiation. Membrane porosity increased from 63.2 to 67.7%; however, the average pore size decreased from 88 to 23 nm after laser modification. The impact of laser wavelength and irradiation time on the rejection of protein (bovine serum albumin, BSA) and the fractions of soluble microbial products (as protein and carbohydrate) was systematically investigated. A maximum rejection of 32.2% and 41.9% was obtained for carbohydrate and protein when activated sludge was filtrated through modified membrane. Moreover, 100% BSA rejection was obtained by the modified membrane when BSA solution was filtrated. The modified membranes were extensively characterized by AFM, FTIR, SEM, and mechanical strength test analyses to observe morphological changes of the membrane before and after modification. The results showed that laser irradiation was changed the membrane morphology. Our results presented that laser-modified membranes with red wavelength changed the pore size, porosity, hydrophilicity of the pristine membrane. Also, membrane surface melting was revealed with a study called “Thermal Analysis on Membrane Surface Modelled 3D” using Solidworks CAD/CAM software. The results obtained from Solidworks thermal analysis was presented with 98.7% ratio of successful approach.
关键词： membrane biofouling,Membrane modification,semiconductor diode laser,activated sludge filtration
更新于2025-09-23 15:19:57