A novel self-assembled monolayer for enhanced growth of poly-N-phenylpyrrole

A novel electrode modification scheme is presented which facilitates the enhanced nucleation and growth of the electrically conducting polymer poly-N-phenylpyrrole. The terminal amino groups of gold working electrodes modified with 4-aminothiophenol (4-ATP) are converted to pyrroles in a simple, one-step reaction. This conversion was confirmed by cyclic voltammetry, with the oxidation potential of the self-assembled monolayer (SAM) shifting from 0.75 V vs. Ag/AgCl for the 4-ATP modified electrode to ∼0.90 V for the pyrrole terminated monolayer. Thus modified, the electrodes were used for the subsequent electrochemical growth of poly-N-phenylpyrrole. Comparison of polymer films formed on the modified vs. unmodified electrode surface by cyclic voltammetry reveals a marked difference in the growth characteristics of the films, particularly in the nucleation step.