INTERLAYER ELECTRON-TRANSFER IN PORPHYRIN LANGMUIR-BLODGETT MULTILAYER-MODIFIED GOLD ELECTRODES

Interlayer electron transfer in electroactive Langmuir-Blodgett multilayer-modified electrodes was studied. A model for the theoretical treatment of cyclic voltammetry (CV) was proposed by developing the models for ultra-thin film modified electrodes by Laviron and by Daifuku et al. Cyclic voltammetry was carried out with hematoporphyrin(IX) bis (tridecanoyl ether) Ru(II) (pyridine)2 complex [RuHP(Py)2] modified gold electrodes. The amount of charge flowing during the sweep is proportional to the number of monolayers. Then CV with a three-monolayer modified electrode was carried out at sweep rates from 0.05 to 102.4 V s-1. Good agreement was obtained between the experimental and the simulated cyclic voltammograms, and the electron diffusion coefficient for the interlayer electron transfer was determined to be 0.8-1.6 × 10-11 cm2 s-1. © 1990.