Synthesis and functional properties of new optical pH sensor based on benzo[de]anthracen-7-one immobilized on the viscose

The synthesis of a new pH sensor based on the fluorescent water-soluble 1-[(7-oxo-7H-benzo[de]anthracen-3-ylcarbamoyl)-methyl]-pyridinium chloride is described. The molecule displays colour change from yellow to orange-reddish as a function of pH in aqueous solution. Viscose fabric could be used as a planar sensor for the visualization of pH gradients via imaging in two dimensions over large surfaces with highly local resolution. The results from colour measurement showed that the dyed viscose fabric is suitable for “naked eye”, on-line, reversible solid-state pH sensor in the alkaline region.