Other Applications of Ion-Exchange Polymers

SPEl-based devices. This probably constitutes the main reason that induced the development of a new class of amperometric gas sensors these are based on a thin layer of a room temperature ionic liquid deposited on the surface of either a three electrode cell or a microelectrode array [26-28]. 

Finally, note that Nafion is most frequently involved in electrode coatings for reasons that differ from those previously discussed. Although it is difficult to compile an exhaustive list of all the possible applications of similar electrode deposits, two specific applications deserve to be cited. 

The former crmsists of a significant enhancement of sensor selectivity when Nafion is added as the outermost layer of an electrode coating the electrocatalytic properties of many electrode coatings that are the object of different chapters of this monograph are combined with the selectivity conferred by this ion-exchange polymer. In this respect, a most frequently reported applicatiOTi is addressed to lower the ascorbic acid interference in amperometric sensors for glucose or for dopamine determination. 

As a further application, Nafion is generally used to stably fix enzymes oti electrode surface the very low solubility of this polymer allows stable deposition of the biomolecule on the transducer, and its marked hydrophilic character allows the enzyme to be effectively in contact with species in solution. 

We emphasize here that, for both these applications, the use of charged polymers different from Nafion is also possible. However, Nafion is commercially available, possesses well known properties and is usually preferred. 

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