Polyanion sensor

Y. Umezawa, M. Kataoka, W. Takami, E. Kimura, T. Koike, H. Nada, Potentiometric Adenosine-Triphosphate Polyanion Sensor Using a Lipophilic Macrocyclic Polyamine Liquid Membrane , Anal. Chem., 60, 2392 (1988)... 

An anthracene-derived chemosensor has been synthesized by Hong and Czarnik. They have shown that this molecule (Figure 90) acts as a metal-ion-insensitive polyanion sensor [117]. This molecule was used for a real-time assay... 

A series of papers have concerned the incorporation of various sensors into lab-on-a-chip devices with, for example, conductivity measurements being combined with poly(methyl methacrylate) microfluidic devices to analyse mixtures of mono- and polyanionic molecules such as proteins [148]. 

Aminoalkyl anthracene derivatives have already featured prominently in this discussion with regard to their proton responsive fluorescence. Some of these in their protonated form also appear in a fluorescent signalling role in association with macromolecular species which is however unconnected with PET action. These mono- or oligocations bind to polyanions such as DNA and heparin [87, 88]. On one hand, this can lead to excited state association between two sensor cations residing on the same polyanionic strand. Acridine orange with its cationic jr-system also exhibits a related behaviour which has been... 

The greatest interest in Nafion (Nf), a perfluorinated polymer with sulfonate groups, derives from its consideration as a proton conducting membrane in fuel cells to many sensor applications [37], The use of Nf and other polyanions to control ion-transport during electrode reaction is a recurring theme [38], The electrodeposition of platinum nanoparticles at the Nafion (Nf) modified glassy carbon (GC) electrode (GC/Nf/Ptnano) by the two-step method... 

FIGURE 7.10 Schematic sensor build-up of an FED with layer-by-layer adsorbed PE multilayers of polycationic and polyanionic composition. 

PPy is known to exhibit anionic or cationic potentiometric responses depending on the doping ion. PPy films doped with mobile inorganic anions show anionic sensitivity, while PPy films doped with anions of low mobility such as sulfate, large organic anions, or polyanions show cationic sensitivity. This bifunctionality of ionic and redox sensitivity makes PPy apphcable as an all-sohd-state, ion-selective electrode. All-solid-state, potentiometric PPy sensors were developed for potassium and sodium sensing, which showed better response time, selectivity and most importantly long-term stabihty than the coated wire electrode [130]. 

ATP is involved in most biochemical metabolism processes. The importance of ATP has inspired chemists to design chemical sensors for ATP and other phosphates. Owing to its polyanionic nature, receptors with... 

Unlike poly[Co(6>-NH2)TPP] electrodes, sensors based on poly[Co(p-OH)TPP] do not respond to anions such as perchlorate, iodide, salicylate, nitrate, or thiocyanate, even at concentrations as high as 5xlO"3 M (experiments performed at pH 6.0). This lack of response to anions has been attributed to Donnan exclusion due to the polyanionic character of the poly[Co(p-OH)TPP] film. The polyanionic nature of these films was verified experiment ly based on the incorporation of the electroactive cation Ru(NH3)6 (40),... 

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