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排序方式: 共有245条查询结果,搜索用时 15 毫秒
101.
《Electroanalysis》2004,16(19):1637-1641
A novel nitrite sensor was developed based on the immobilization of a partially quaternized poly(4‐vinylpyridine) complexed with [Os(bpy)2Cl]+/2+ (PVP‐Os) in a porous TiO2 sol‐gel matrix by a vapor deposition method. The preparation process simplified the traditional sol‐gel process and prevented the cracking of conventional sol‐gel derived glasses. Electrochemical behavior of the sensor was characterized by cyclic voltammetry and shows excellent electrocatalytic response for the reduction of nitrite. Effect of operating potential on electrochemical responses of the sensor was explored for optimum analytical performance by using the amperometric method. The stability of the sensor was also evaluated. 相似文献
102.
Kudelski A 《Talanta》2008,77(1):1-8
In this article interaction of transition metal complexes with DNA and its applications in electrochemical DNA biosensors as hybridization indicator or electroactive marker of DNA are reviewed. Special emphasis has been given to the efforts for the development of new transition metal complexes and their interaction to DNA. DNA and polymers covalently conjugated with transition metal complexes were also reviewed. 相似文献
103.
Wei-xia Tu~ 《高分子科学》2008,(1):23-29
Several PVP-stabilized colloidal platinum metals nanoparticles have been synthesized and characterized by FTIR and TEM.Comparing with the pure PVP,carbonyl groups of PVP in the mixture of PVP and the metal precursors or in the PVP-stabilized metal nanoparticles have obvious peak shifts in FTIR spectra.The peak shifts reveal the interaction between PVP and the metal species.The interaction between PVP and metal precursors has effect on the formation of the colloidal metal nanoparticles.Strength of the int... 相似文献
104.
105.
《先进技术聚合物》2018,29(2):835-842
In this study, the influence of variations in chain length of polyvinylpyrrolidone (PVP) brushes on the blood compatibility of silicon wafer surfaces to which they were chemically attached was studied. Si surfaces were functionalized with various lengths of PVP brush using atom transfer radical polymerization technology and confirmed by elliptical polarized light, atom force microscopy, and X‐ray photoelectron spectroscopy. The blood compatibility of these biointerfaces were systematically investigated by measuring protein adsorption, clotting time, platelet adhesion, contact activation, and complement activation. The results indicate that the hemocompatibility of the surfaces was highly related to PVP brush chain length and hydrophilicity of the surfaces. Our results contribute to rational biointerface design for specific biomedical applications. The results reveal that the PVP brushes with a long chain length have great potential for blood contacting applications due to their reduced protein absorption and cell activation following its contact with blood. 相似文献
106.
Hyun Jeong Jeon Young Chang You Ji Ho Youk 《Journal of polymer science. Part A, Polymer chemistry》2009,47(12):3078-3085
An amphiphilic block copolymer of poly(N‐vinyl pyrrolidone)‐b‐poly(ε‐caprolactone) (PVP‐b‐PCL) was synthesized by a combination of cobalt‐mediated radical polymerization (CMRP) and ring‐opening polymerization (ROP). The micellar characteristics of this copolymer were subsequently investigated. PVP (Mn = 11,400, Mw/Mn = 1.32) was synthesized at 20 °C via CMRP using a molar ratio of [VP]0/[V‐70]0/[Co]0 = 150/8/1. The PVP was then reacted with 2,2′‐azobis[2‐methyl‐N‐(2‐hydroxyethyl)propionamide] (VA‐086) to modify its cobalt complex chain end to a hydroxyl group. The cobalt (Co) content in the resulting PVP‐OH was 1.2 ppm, indicating that all of the covalent Co? C bonds were cleaved and reacted with VA‐086, and that the separated cobalt complexes were successfully removed. The ROP of CL was subsequently carried out using the produced PVP‐OH as a macroinitiator at 110 °C. The GPC trace of PVP‐b‐PCL was monomodal without any tailing caused by the residual PVP‐OH, indicating that the initiation efficiency was very high. The critical micelle concentration (CMC) of PVP‐b‐PCL (Mn = 18,000, Mw/Mn = 1.35) was 0.015 mg/mL. The PVP‐b‐PCL micelles were spherical in shape with an average diameter of 105 nm. The nanosized PVP‐b‐PCL micelles show promise as novel drug carriers in biomedical and pharmaceutical applications. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3078–3085, 2009 相似文献
107.
用水热合成方法制备了PVP表面修饰CdS纳米棒,用XRD,TEM,TG-DTA,IR,UV-Vis,PL等光谱技术进行了表征。与未修饰的CdS纳米棒相比,PVP修饰后的CdS纳米棒具有更均匀的尺寸分布,吸收光谱具有结构峰特征,其荧光发射谱增强。 相似文献
108.
以无机稀土氧化物为原料、2-甲氧基乙醇为溶剂、PVP为胶粘剂、PEG200为有机分散剂,采用溶胶-凝胶工艺成功制备出Gd2O3∶Eu3+透明闪烁薄膜。通过2次涂复,薄膜厚度达到了1.5μm,膜层均匀、无散射颗粒、无裂纹,可见光区的透射率约为80%。研究表明PVP在厚膜烧结过程中可以松弛膜的结构、减小应力的出现,避免厚膜开裂,同时还可以提高溶胶的粘度,在厚膜制备中起到了关键作用。此外,我们还研究了Gd2O3∶Eu3+闪烁薄膜的激发、发射和发光衰减时间谱,结果表明,该薄膜发光性能优良,可初步满足X射线成像用闪烁薄膜的要求。 相似文献
109.
《Analytical letters》2012,45(15):2951-2964
ABSTRACT The modified glassy carbon electrodes prepared by simultaneously covering with [Os(bpy)2(PVP)10Cl]+ redox polymer and Nafion film exhibited excellent electrocatalytic activity for the oxidation of dopamine (DA). Dual linear regions between 1.0x10?8-1.8x10?5 M and 1.8x10?5-4.0x10?4 M with correlation coefficients of 0.998 and 0.995, respectively, were obtained for log-log plots of catalytic current versus DA concentration. The detection limit for DA determination was ca. 5 nM with 3σ. The dual-film modified electrodes eliminated efficiently the interference from AA presence in a 1000-fold concentration ratio and showed excellent reproducibility for the determination of DA. The modified electrodes have been used to determine DA concentration with both cyclic voltammetric and chronoamperometric techniques. Electrocatalytic kinetics have been studied using a rotating disk electrode. Both the addition of Nafion film and an increase in DA concentration resulted in a decrease in the electrocatalytic rate constant. An apparent Michaelis-Menten constant of 1.3 mM and maximum catalytic current of 88μA were evaluated from the chronoamperometric measurements. 相似文献
110.
采用静电纺丝技术将聚苯胺(PANI)和稀土配合物[Tb(BA)3phen]掺杂到高分子材料(PVP)中,制备出一类新型的具有光电双功能的Tb(BA)3phen/PANI/PVP复合纳米纤维.用扫描电子显微镜(SEM)、X射线能量色散谱仪(EDS)、荧光光谱仪及宽频介电松弛谱仪对样品进行了表征.结果表明,复合纳米纤维直径为(331±43)nm.在276 nm紫外光激发下,Tb(BA)3phen/PANI/PVP复合纳米纤维发射出主峰位于491,547和585 nm的绿光,对应Tb3+的5D4→7F6,5D4→7F5和5D4→7F4跃迁.当Tb(BA)3phen∶PANI∶PVP的质量比为15∶10∶100时,复合纳米纤维的荧光发射最强,其电导率随PANI含量的增大而升高,在PANI∶PVP为50%(wt%)时,其电导率在高频(106Hz)下达1.531×10-6S/cm. 相似文献