Co-immobilization of several dyes on optodes for pH measurements

In order to measure the pH-zone with active optodes, the principles and effects of co- immobilization of several dyes are studied. Two techniques are compared: dye binding on poly.N (vinylimidazole) (PVI) grafted on silica fiber; and dye absorption on a cross-linked styrene-divinylbenzen resin at the end of fiber. The possibilities of these techniques with several reagents co-immobilized on the same optode are discussed.