Electrochemical characterization of mixed self-assembled films of water-soluble single-walled carbon nanotube-poly(m-aminobenzene sulfonic acid) and Iron(II) tetrasulfophthalocyanine

Abstract

The redox activities of water-soluble iron(II) tetrasulfophthalocyanine (FeTSPc) and single-walled carbon nanotube-poly(m-aminobenzene sulfonic acid) (SWCNT-PABS) adsorbed on a gold surface precoated with a self-assembled monolayer (SAM) of 2-dimethylaminoethanethiol (DMAET) have been described. Atomic force microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy were employed to probe the buildup and formation of their thin solid films on the gold surface. The solid films exhibited excellent electrochemical stability. The electrode based on the mixed hybrids (Au-DMAET-SWCNT-PABS/FeTSPc) exhibited the fastest electron transport (ko0.4 cm s-1) compared to other electrodes (~0.2 cms-1), suggesting the ability of the SWCNT-PABS to act as efficient conducting species that facilitate electron transport between the integrated FeTSPc and the underlying gold substrate. Given the paucity of literature in the SAMs of water-soluble phthalocyanine complexes, the proposed fabrication strategy could potentially be extended to other water-soluble metallophthalocyanines and related organometallic complexes