Spectral properties of hemicyanine dye in confinement by helical amylose

Hemicyanine dye structure is modified with a C₁₆-alkyl chain to amino-head and a C_1, C₈ or C₁₆ alkyl to pyridinium-tail. Spectral properties of the dyes in supramolecular inclusion complexation with amylose are studied in order to assess the mono-functional polarity sensing activity of the pyridinium cations in DMSO-H₂O mixtures. Inclusion complexation brings the γ_max of C₁₆DASPC₁ dye to a blue-shift (relative to that of the free dye state) while that of C₁₆DASP(C₈ and C₁₆) dyes remains almost unchanged.