Design of a calcium-selective optode membrane based on neutral ionophores

Article abstract of DOI:10.1021/ac00206a018

A large variety of new optical ion-sensor constructions (optodes) can now be realized by using a poly (vinyl chloride) (PVC) membrane that incorporates a cation-selective neutral ionophore, a specially tailored H⁺-selective neutral chromolonophore, and lipophilic anionic sites in the same plasticized PVC membrane. Such membranes generally combine the advantages of a highly selective and reversible recognition of given ionic substrates and of a straightforward optical transduction of the recognition process. The present membrane exhibits the theoretically expected absorbance response to Ca²⁺ activities in different pH-buffered samples. Dynamic range, reproducibility, response time, long-time stability, and selectivity of the new optode membrane are discussed.