In ion-selective electrodes

Individual polyethers exhibit varying specificities for cations. Some polyethers have found appHcation as components in ion-selective electrodes for use in clinical medicine or in laboratory studies involving transport studies or measurement of transmembrane electrical potential (4). The methyl ester of monensin [28636-21 -7] i2ls been incorporated into a membrane sHde assembly used for the assay of semm sodium (see Biosensors) (5). Studies directed toward the design of a lithium selective electrode resulted in the synthesis of a derivative of monensin lactone that is highly specific for lithium (6). 

Kimura and coworkers [17], Diamond [18], and Damien et al. [19] have described that the polymeric calix-[4]arenes have been used as ionophores in ion selective electrodes for Na (based on calixarene esters and amides) and for Na and Cs (based on p-alkylcalixarene acetates). The electrodes are stated to function as poten-tiometric sensors as well, having good selectivity for primary ion, virtually no response to divalent cations, and being stable over a wide pH range. 

Koryta, J. Electrolysis at the interface of two Immiscible Electrolyte Solutions and its Analytical Aspects, in Ion-Selective Electrodes. 3rd. Symposium held at Matrafured, Hungary 1980, ed. Pundor, E., Elsevier, Amsterdam—Oxford—New York 1981... 

Horvai, G., and Pungor, E., Precision of the Double Known Addition Method in Ion-Selective Electrode Potentiometry, Anal. Chem. 55, 1983, 1988-1990. 

Kobos, R. K. Potentiometric Enzyme Methods, in Ion-Selective Electrodes in Analytical Chemistry, Vol. 2 (Freiser, H., ed.) New York Plenum Press, 1980, p. I... 

Covington, A. K., and M. J. F. Rebello, Reference electrodes and liquid junction effect in ion-selective electrode potentiometry, lon-Sel. Electrode Revs., 5, 93 (1983)... 

The material is presented in 17 chapters, covering topics such as trends in ion selective electrodes, advances in electrochemical immunosensors, modem glucose biosensors for diabetes management, biosensors based on nanomaterials (e.g. nanotubes or nanocrystals), biosensors for nitric oxide and superoxide, or biosensors for pesticides. 

A different direction in ion-selective electrode research is based on experiments with antibiotics that uncouple oxidative phosphorylation in mitochondria [59]. These substances act as ion carriers (ionophores) and produce ion-specific potentials at bilayer lipid membranes [72]. This function led Stefanac and Simon to obtain a new type of ion-selective electrode for alkali metal ions [92] and is also important in supporting the chemi-osmotic theory of oxidative phosphorylation [69]. The range of ionophores, in view of their selectivity for other ions, was broadened by new synthetic substances [1,61]. 

In the years from 1969 to 1972, Orion Research published a magazine devoted to developments in ion-selective electrodes [78], and, later, a guide to their products [34a], Since 1979, the journal Ion-Selective Electrode Reviews has been published semi-annually [39a]. 

P. Buck, Theory and Principles of Membrane Electrodes, in Ion-Selective Electrodes in Analytical Chemistry (ed. R Freiser), Vol I, Plenum Press,... 

K. Covington and P. Davison, Liquid ion exchanger types, in Ion-Selective Electrode Methodology, Vol. I, CRC Press, Boca Raton (1979), p. 85. 

Hulanicki and A. Lewenstam, Interpretation of the Response Mechanism of Solid-State Ion-Selective Electrodes Regarding Diffusion Processes, in Ion-Selective Electrodes (ed. E. Pungor and I. Buz s), International Conference held in Budapest 1977, Akad6miai Kiad6, Budapest and Elsevier, Amsterdam (1978). 

M. Band and T. Treasure, Ion-Selective Electrodes in Medicine and Medical Research, in Ion-Selective Electrode Methodology (ed. A. K. Covington),... 

K. Covington, Reference Electrodes, in Ion-Selective Electrodes (ed. R. A. Durst) NBS No. 314 Special Publ., Washington (1969). 

KOrOs and M. Burger, Bromide selective electrode for use in following the Zhabotindu-type oscillating chemical reaction, in Ion-Selective Electrodes (ed. E Pungor), Symposium 1972, Akademiai Kiad6, Budapest (1973), p. 191. Koryta,y4na/. Chim. Acta 61, 329 (1972). 

They lead to the formation of a membrane potential at BLM and thick membranes [30,49, 122, 156, 193], forming a basis for their use in ion-selective electrodes, as was first demonstrated by Stefanac and Simon [202]. 

The Ba ISE containing the acyclic membrane carrier nonylphenoxy-poly(ethylenoxy)ethanol described by Levins [123] opened new fields in ion-selective electrodes based on synthetic acyclic ionophores. Simon and coworkers synthesized several hundred substances [3] that can be used for ISEs to determine alkaline earth ions, primarily Ca [4], and also [190], etc. (for a review, see [133, 154]). A natural ionophore for calcium is the antibiotic,... 

P. Vadgema, Enzyme Electrodes, in Ion-Selective Electrode Methodology... 

An important advance in ion-selective electrodes (ISEs) and related systems was based on the concept of polymeric liquid membranes developed by Eisenman [122]. The principle of this approach was to incorporate an organic compound as the ionophore into a polyvinyl chloride membrane... 

R. VIRTANEN, in "Ion-Selective Electrodes 3", E. PUNGOR (Ed.), Akademiai Kad6, Budapest Elsevier Science Publishers, Amsterdam, 1981, p. 375. 

Buck, R. P, In Ion-Selective Electrodes in Analytical Chemistry Preiser, H., Ed. Plenum Press New York, 1978, Chapter l,pp. 1-141. 

Umezawa, Y Sugawara, M. Kataoka, M. Odashima, K. In Ion-Selective Electrodes, Pungor, E., Ed. Akad6miai Kiad6 Peigamon Press Budapest, Oxford, 1989, Chapter 5, pp. 211-234. 

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