CALIXARENES AS ACTIVE AGENTS FOR CHEMICAL SENSORS

Calixarenes are a relatively new family of ion receptors that are receiving increasing attention due to their ease of synthesis and multiple sites for structural modification. Calixarene derivatives can be incorporated into plasticized poly(vinylchloride) membranes to produce functioning ion-selective electrodes (ISEs). We have investigated the effect of some structural permutations on the selectivity of the corresponding ISEs. Sensors selective for sodium, potassium and caesium have been successfully fabricated. A further aspect of the work has been the development of a computer-based method for accurate selectivity and electrode slope determination. In addition, improved analytical performance arising from the use of sparingly selective ionophores to provide crosstalk between very selective electrodes in ISE arrays is demonstrated.