共查询到20条相似文献,搜索用时 531 毫秒
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低维ZnO纳米材料* 总被引:1,自引:0,他引:1
本文主要综述了近年来ZnO纳米材料制备领域的一些新方法,简单比较了各种方法之间的优缺点;讨论了制备不同形貌的ZnO纳米材料的影响因素,其中重点讨论了表面活性剂的作用;介绍了ZnO纳米材料的性质及其可能的应用领域;并对ZnO纳米材料的发展前景进行了展望。 相似文献
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本文合成了含酰胺基团和不含酰胺基团的两类Gemini阳离子表面活性剂,测定了其表面活性参数,研究了酰胺基团对表面活性剂的表面活性和聚集行为的影响。结果表明,酰胺基团提高了Gemini阳离子表面活性剂的临界胶团浓度,降低了胶团聚集数,增强了胶团微极性,增大了表面活性剂的饱和吸附量。 相似文献
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基础化学实验室的建设与管理 总被引:2,自引:0,他引:2
化学实验室是全面完成化学教学任务的重要基地。 我院2002年建立了设备比较先进的化学实验室,给学生创造了良好的实验条件,并进行了科学化的管理,规定了各种规章制度和有关职责,较好地完成了化学教学任务。在实践中。采取:固定优秀代课教师兼管,勤工助学学生帮忙的管理办法,既减轻教师的劳动强度,又培养了学生的技能,且协调了各种关系,有利于化学教学质量的提高。 相似文献
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Marion Costella Quentin Avenas Marie Frna‐Robin Julien Marchalot Pascal Bevilacqua Paul G. Charette Michael Canva 《Electrophoresis》2019,40(10):1417-1425
The performance of conventional surface plasmon resonance (SPR) biosensors can be limited by the diffusion of the target analyte to the sensor surface. This work presents an SPR biosensor that incorporates an active mass‐transport mechanism based on dielectrophoresis and electroosmotic flow to enhance analyte transport to the sensor surface and reduce the time required for detection. Both these phenomena rely on the generation of AC electric fields that can be tailored by shaping the electrodes that also serve as the SPR sensing areas. Numerical simulations of electric field distribution and microparticle trajectories were performed to choose an optimal electrode design. The proposed design improves on previous work combining SPR with DEP by using face‐to‐face electrodes, rather than a planar interdigitated design. Two different top‐bottom electrode designs were experimentally tested to concentrate firstly latex beads and secondly biological cells onto the SPR sensing area. SPR measurements were then performed by varying the target concentrations. The electrohydrodynamic flow enabled efficient concentration of small objects (3 μm beads, yeasts) onto the SPR sensing area, which resulted in an order of magnitude increased SPR response. Negative dielectrophoresis was also used to concentrate HEK293 cells onto the metal electrodes surrounded by insulating areas, where the SPR response was improved by one order of magnitude. 相似文献
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The kinetics of the adsorption of metal ions onto a thiolated surface and the selective and quantitative sensing of metal ions were explored using surface plasmon resonance (SPR) spectroscopy. The target metal ion was an aqueous solution of Pt2+ and a thin-gold-film-coated glass substrate was modified with 1,6-hexanedithiol (HDT) as a selective sensing layer. SPR spectroscopy was used to examine the kinetics of metal ion adsorption by means of the change in SPR angle. The selectivity of the thiolated surface for Pt2+ over other divalent metal ions such as Cu2+, Ni2+, and Cd2+ was evident by the time-resolved SPR measurement. SPR angle shift, deltatheta(SPR), was found to increase logarithmically with increasing concentration of Pt2+ in the range of 1.0 x 10(-5)-1.0 mM. The rate of Pt2+ adsorption on HDT observed at both 0.1 and 1 mM Pt2+ accelerates until the surface coverage reaches approximately 17%, after which the adsorption profile follows Langmuirian behavior with the surface coverage. The experimental data indicated that heavy metal ions were adsorbed to the hydrophobic thiolated surface by a cooperative mechanism. A mixed self-assembled monolayer (SAM) composed of HDT and 11-mercaptoundecanoic acid was used to reduce the hydrophobicity of the thiol-functionalized surface. The addition of hydrophilic groups to the surface enhanced the rate of adsorption of Pt2+ onto the surface. The findings show that the adsorption of metal ions is strongly dependent upon the hydrophilicity/hydrophobicity of the surface and that the technique represents an easy method for analyzing the adsorption of metal ions to a functionalized surface by combining SPR spectroscopy with a SAM modification. 相似文献
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A novel method to prepare surface plasmon resonance(SPR) sensor chips based on grafted imprinted polymer is explored. Benzophenone photografting system is used to grow molecularly imprinted polymer(MIP) films from the modified surface of gold substrate.The surface morphology and thickness of MIP films were investigated by scanning electronic microscope(SEM).The adsorption properties of sensor chip were studied by SPR spectroscopy.The results demonstrate that nano-MIP films can be constructed on the surface of gold substrate with the good adsorption of template molecules. 相似文献
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This study shows the detection of (N-acyl) homoserine lactones (AHLs or HSL) with monoclonal antibodies via a surface plasmon resonance (SPR)-based immunosensor in comparison to conventional microtiter plate-based enzyme-linked immunosorbent assay (ELISA). An HSL derivative, named HSL2 (Table 1), was attached to bovine serum albumin (BSA) and the conjugate (HSL2-BSA-r2) was either covalently immobilised on the SPR sensor chip surface via free amino groups or via adsorption on the ELISA polystyrene plate surface. With a newly developed rat monoclonal antibody (mAb HSL1/2 2C10), AHLs were detected sensitively in a competitive format with SPR and ELISA. Well comparable experiments between SPR and ELISA could be obtained in buffers. Moreover, the SPR sensor surface with the immobilised conjugate HSL2-BSA-r2 could be regenerated at least 340 times (regeneration cycles) without loss of activity. The measurement time per cycle was approximately 15 min. The competitive detection format for SPR and ELISA allowed the detection in the μg L−1 range. 相似文献
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Maalouli N Gouget-Laemmel AC Pinchemel B Bouazaoui M Chazalviel JN Ozanam F Yang Y Burkhard P Boukherroub R Szunerits S 《Langmuir : the ACS journal of surfaces and colloids》2011,27(9):5498-5505
Monolayers of metal complexes were covalently attached to the surface of lamellar SPR interfaces (Ti/Ag/a-Si(0.63)C(0.37)) for binding histidine-tagged peptides with a controlled molecular orientation. The method is based on the activation of surface acid groups with N-hydroxysuccinimide (NHS), followed by an amidation reaction with (S)-N-(5-amino-1-carboxypentyl)iminodiacetic acid (NTA). FTIR and X-ray photoelectron spectroscopy (XPS) were used to characterize each surface modification step. The NTA modified SPR interface effectively chelated Cu(2+) ions. Once loaded with metal ions, the modified SPR interface was able to bind specifically to histidine-tagged peptides. The binding process was followed by surface plasmon resonance (SPR) in a droplet based configuration. The Cu(2+)-NTA modified interface showed protein loading comparable to commercially available NTA chips based on dextran chemistry and can thus be regarded as an interesting alternative. The sensor interface can be reused several times due to the easy regeneration step using ethylenediaminetetraacetic acid (EDTA) treatment. 相似文献
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This paper experimentally and theoretically investigates the influence of an underlying metallic substrate (i.e., gold and silver) on the surface plasmon resonance (SPR) of labeled gold nanoparticles and the concomitant impact on the surface-enhanced Raman scattering (SERS) signal from the labels. These experiments employ nanoparticles of varied sizes (30-100 nm) that are coated with a bifunctional Raman scatterer composed of (1) a disulfide for chemisorption to the nanoparticle surface, (2) a succinimidyl ester for formation of a covalent linkage to an amine-terminated self-assembled monolayer on the underlying substrate, and (3) an aryl nitro group with an intrinsically strong Raman active vibrational mode. This approach allows facile systematic assessments of how variations in nanoparticle size, substrate composition, and the gap between the nanoparticle and substrate affect the SPR of the bound particles. Both UV-vis transmission and reflection absorption (incident angle of 58 degrees ) spectroscopy are used to characterize the effect of each of these parameters on SPR. These results are then correlated with SERS enhancement factors (EFs) that were determined by accounting for particle surface concentrations, which were measured by atomic force microscopy, and the absolute number of labels, which were calculated on the basis of the surface area of each of the different-sized particles. All SERS spectra were collected at an incident angle of 58 degrees with respect to the surface normal. As expected, the SPR for particles in solution red-shifts with increasing particle size. More importantly, the SPR moves to even longer wavelengths as the size of immobilized particles increases and as the gap between the immobilized particle and substrate decreases. The red shift is also greater for a gold nanoparticle tethered to a gold substrate compared to a silver substrate. A theoretical model for the extinction of a particle above a flat substrate, corrected for surface scattering, radiation damping, and dynamic depolarization, is also briefly detailed. SPR results calculated with the model are consistent with the shifts observed in the SPR position for each of the manipulated experimental variables. The largest EFs are found for samples with an SPR maximum (lambda(max)) between the wavelengths for laser excitation (633 nm) and the Raman band for the symmetric nitro stretch of the particle coating (690 nm). As an example, an order of magnitude in the SERS enhancement factor is gained for a 60-nm particle immobilized 1.2 nm above a gold substrate (SPR lambda(max) = 657 nm) compared to that for a 30-nm particle (SPR lambda(max) = 596 nm). 相似文献
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The surface plasmon resonance (SPR) sensor was fabricated by depositing silver thin film on the surface of hetero-core structured fiber optic. The SPR sensor based on hetero-core structured fiber optic was applied to measure refractive index of sucrose solution and fruit juices. The sensor part was immersed in sucrose solution and/or juice and the propagating light spectra were measured. It was shown that the fiber optic SPR sensor showed a good agreement with that measured by conventional refractometer. 相似文献
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We report here on the fabrication and characterization of stable thin films of amorphous silica (SiO(x)) deposited on glass slides coated with a 5 nm adhesion layer of titanium and 50 nm of gold, using the plasma-enhanced chemical vapor deposition (PECVD) technique. The resulting surfaces were characterized using atomic force microscopy (AFM), ellipsometry, contact angle measurements, and surface plasmon resonance (SPR). AFM analysis indicates that homogeneous films of silica with low roughness were formed on the gold surface. The deposited silica films showed excellent stability in different solvents and in piranha solution. There was no significant variation in the thickness or in the SPR signal after these harsh treatments. The Au/SiO(x) interfaces were investigated for their potential applications as new surface plasmon resonance sensor chips. Silica films with thicknesses up to 40 nm allowed visualization of the surface plasmon effect, while thicker films resulted in the loss of the SPR characteristics. SPR allowed further the determination of the silica thickness and was compared to ellipsometric results. Chemical treatment of the SiO(x) film with piranha solution led to the generation of silanol surface groups that have been coupled with a trichlorosilane. 相似文献
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Jung J Yuk JS Na K Kim O Lee J Yun K Ha KS Hyun J 《Langmuir : the ACS journal of surfaces and colloids》2007,23(20):10403-10406
In this study, we demonstrate a simple method to fabricate surface plasmon resonance (SPR) imaging microarrays using polymer micropatterns. The use of a micrometer-scale polymeric optical screen (microPOS) passivates the region deposited with polymer by completely removing SPR signals or by saturating the SPR signal far beyond the detection range of SPR imaging. Two schemes were suggested to create a surface microPOS by either micropatterning a thick insulating layer before deposition of a metal layer (complete removal of SPR) or after deposition of a metal layer (saturation of SPR signal). The two schemes were successfully applied for the imaging of biological adsorption with a high imaging resolution of approximately 100 microm/pattern and 10 microm separation. The validity of the system was verified with a biotin-streptavidin system as a model for the systematic binding of biomolecules. Further, binding of prostate-specific antigen (PSA) onto the anti-PSA SPR microarray was demonstrated as a useful method for detecting a cancer marker. 相似文献
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Soh N Tokuda T Watanabe T Mishima K Imato T Masadome T Asano Y Okutani S Niwa O Brown S 《Talanta》2003,60(4):733-745
A surface plasmon resonance (SPR) based biosensor was developed for monitoring 2,4-dichlorophenol, a known dioxin precursor, using an indirect competitive immunoassay. The SPR sensor was fabricated by immobilizing a gold-thin layer on the surface of an SPR sensor chip with an anti-(2,4-dichlorophenol) antibody using a gold binding polypeptide (GBP) and protein G. The SPR response based on the antigen-antibody reaction in a flow system was measured by injecting a 2,4-dichlorophenol sample solution into the flow system in which the SPR sensor was located. In a direct immunoassay system using the modified sensor chip, no significant SPR angle shift less than 0.001° was observed when a 25 ppm of 2,4-dichlorophenol solution was injected. In order to improve the sensitivity of the SPR sensor, an indirect competitive immunoassay method was used in conjunction with the SPR sensor system using 2,4-dichlorophenol conjugated with bovine serum albumin (BSA). In the competitive assay, a 350 ppm 2,4-dichlorophenol-BSA conjugate solution containing 2,4-dichlorophenol at various concentrations (10-250 ppb) were injected into the SPR sensor system. The sensitivity of this indirect immunoassay was found to be extremely sensitive, compared to the direct one, and a detection limit of 20 ppb was estimated. Verification that the use of GBP for immobilizing the antibody on the sensor chip enhanced the sensitivity to 2,4-dichlorophenol was obtained by comparing the procedure with another modification, in which BSA was used instead of GBP for immobilizing the antibody on the sensor chip. The affinity constant of 2,4-dichlorophenol and its conjugate to the antibody were estimated form the SPR response. 相似文献