排序方式: 共有4条查询结果,搜索用时 15 毫秒
1
1.
Rihab Nasraoui Jean-François Bergamini Soraya Ababou-Girard Florence Geneste 《Journal of Solid State Electrochemistry》2011,15(1):139-146
We investigate here the derivatization of pyrolyzed photoresist film (PPF) surface by anodic oxidations of amino-containing
linkers in aqueous medium. As an example of application, nitrogen macrocycles are then covalently immobilized by chemical
reactions with the modified surface. The surface coverage is estimated by X-ray photoelectron spectroscopic analyses and cyclic
voltammetry using redox probes, and the thickness of the film is measured by atomic force microscopy from scratching experiments.
The surface coverage increases when two successive grafting processes are carried out and stops after the third electrolysis.
The influence of the electrolyte medium on the thickness of the film is also highlighted. 相似文献
2.
Walcarius A Nasraoui R Wang Z Qu F Urbanova V Etienne M Göllü M Demir AS Gajdzik J Hempelmann R 《Bioelectrochemistry (Amsterdam, Netherlands)》2011,82(1):46-54
Complexes of the (2,2'-bipyridyl) (pentamethylcyclopentadienyl)-rhodium family ([Cp*Rh(bpy)Cl](+), which is actually hydrolyzed in the form of [Cp*Rh(bpy)H(2)O](2+) in aqueous medium) are suitable solution-phase mediators likely to regenerate nicotinamide cofactors associated to dehydrogenases involved in many biocatalytic applications. Their practical application as bioelectrocatalysts, e.g., in fine chemicals synthesis or biosensors, remains however restricted to their durable immobilization in an active form onto solid electrode surfaces. This paper reports some new observations on the electrocatalytic properties of this mediator towards NAD(+) reduction, notably the critical effect of pH and cofactor-to-mediator concentration ratio, and investigates the behavior of a series of ([Cp*Rh(bpy)Cl](+)) derivatives bearing various substituents on the bipyridine ligand in view of their subsequent integration in electrochemical bioreactors. It will be shown that such compounds containing S- or N- moieties (i.e., often used as precursors to functionalize electrode surfaces) lead to inactivation of the electrocatalyst because their interaction with the Rh center prevents the formation of the active rhodium hydride complex. It was thus necessary to find another strategy of immobilization, and we found that adsorption of [Cp*Rh(bpy)Cl](+) by π-stacking on single-walled carbon nanotubes is an effective mean to reach this goal, leading to efficient and stable catalytic responses for NAD(+) reduction. Preliminary electroenzymatic experiments in the presence of d-sorbitol dehydrogenase further point out the interest of this approach for bioelectrocatalysis purposes and provide the proof-of-concept for this immobilization strategy. 相似文献
3.
A flow electrochemical sensor for trace analysis of lead, using TETRAM-modified graphite felt electrode is reported here. TETRAM ligands are covalently immobilized on the graphite felt by chemical reactions on amino acid linkers, previously attached to the electrode by an electrochemical process. The detection is performed in two steps: the preconcentration of Pb2+ ions by complexation with immobilized TETRAM and the analysis by linear sweep stripping voltammetry. A calibration curve typical of at least two equilibrium processes is obtained. A limit of detection of 2.5 × 10?8 mol L?1 is reached for a total analysis time of 35 min. Interestingly, the flow sensor shows a good selectivity toward lead in presence of Cu2+, Cd2+, Ni2+, Zn2+ and Co2+ ions. This new sensor exhibits improved sensitivity and selectivity compared to the previously reported sensor using cyclam-modified electrode. It is stable after three uses, using strong acidic medium for the regeneration step. 相似文献
4.
Nasraoui Haythem Driss Zied Kchaou Hedi 《Journal of Thermal Analysis and Calorimetry》2020,140(6):2721-2732
Journal of Thermal Analysis and Calorimetry - Solar chimney power plant (SCPP) is an interesting project to produce clean and sustainable energy. An efficient SCPP system requires a very high... 相似文献
1