Heterogeneous wide range pH-sensing materials allowing ratiometric fluorescence detection based on structurally rigid analogs of 2,6-distyrylpyridine.

The new sensing materials based on the microsized silica gel powder with non-covalently immobilized structurally rigid analogs of 2,6-distyrylpyrydine ((3E,5E)-3,5-dibenzylidene-8-phenyl-1,2,3,5,6,7-hexahydrodicyclopenta[b,e]pyridines) were developed and tested. Most of the investigated compositions demonstrate linear ratiometric fluorescence response on pH in the physiologically important interval (pH 6-9). The compound with the greatest number of protolytic centers within the studied series demonstrated the widest pH sensitivity range, however in this case the analytical signal was the lowest.