Comparative study of the electrodeposition of poly(3-octylthiophene) filmson gold electrodes: Bare and modified with dodecanethiol monomolecular layer

Poly(3-octylthiophene) (p3OT) was deposited potentiostatically on bare and dadecanethiol-coated polycrystalline gold electrodes. The obtained polymer layers were investigated by cyclic voltammetry with use of hydrophobic (fer rocene) and hydrophilic (Ru(NH3)(6)(3+)) redox probes. The study of the mor phology of obtained layers was also carried out by scanning tunneling micro scopy in air. It was found that while p3OT deposited on bare gold contains a number of defects (pores, holes), the polymer deposited on thiol-coated e lectrode is characterized by more compact properties. It was proposed that in this case a complex system is formed where we can differentiate between a "mixed" inner layer consisting of polymer and thiol molecules and an oute r layer of "pure" poly(3-octylthiophene). By "mixed" we understand the poss ibility of both filling the existing defects in the monolayer by the polyme r and, eventually, replacing, with immediate entrapment into the matrix, so me thiol molecules.