Ultra-thin porous glass membranes-An innovative material for the immobilization of active species for optical chemosensors

► Thin porous glass membranes were tested as matrix for optical chemosensors. ► The membrane permeability for water was determined. ► The absorption spectra for the unmodified water-soaked membranes were recorded. ► Thymol blue and a derivative of styryl acridine were covalently immobilized. ► The corresponding absorption spectra during variation of the pH value are shown.