Elucidation of the Adsorption Distribution of Cationic Porphyrin on the Inorganic Surface by Energy Transfer as a Molecular Ruler
journal contributionposted on 14.02.2018, 00:00 by Ayumi Nakayama, Junya Mizuno, Yuta Ohtani, Tetsuya Shimada, Shinsuke Takagi
The adsorption distribution of porphyrin dye on the inorganic surface was examined by the use of Förster resonance energy transfer (FRET). Because the efficiency of FRET depends on the distance between energy donor and acceptor, FRET could be used as a spectroscopic molecular ruler to estimate the adsorption distribution of dyes on the inorganic surface. Saponite and cationic porphyrin were used as an anionic inorganic nanosheet and an adsorbing dye (an energy acceptor) on the clay surface. The edge of saponite was modified by pyrene that is an energy donor, through silane coupling. From the estimation of FRET efficiency, the adsorption distribution of cationic porphyrin is turned out to be biased to the center of the nanosheet surface. The factor to determine such adsorption distribution of cationic porphyrin was discussed based on the electrostatic interactions between anionic nanosheet and cationic porphyrin.