Investigation on disassociation of porphyrin J-aggregates induced by β-cyclodextrins using absorption and fluorescence spectroscopy

In this paper, interaction of meso-tetra-(4-sulfonatophenyl) porphyrin (H4TPPS42−) with three kinds of cyclodextrins, including β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) and methyl-β-cyclodextrin (Me-β-CD) is investigated by absorption and fluorescence spectra. J-aggregates of H4TPPS44− show a sharp peak at 490 nm in UV–vis spectra, while they have no fluorescence emission. The experimental results demonstrate that β-CDs efficiently break aggregates and lead to decrease at 490 nm and increase at 436 nm in absorption spectra, with gradually increasing fluorescence emission. Both inclusion ratios and inclusion constants are correspondingly calculated based on the “double reciprocal method”.