Self-assembled monolayers of 1-(2-cyanoethyl)pyrrole on gold electrode

The self-assembled monolayers (SAMs) of 1-(2-cyanoethyl)pyrrole (CEPY) were immobilized on the gold electrode. Compared with the traditional thiolated SAMs, the CEPY SAMs had certain rigidity. Their electrochemical properties and stability were investigated by cyclic voltammetry and ac-impedance measurements. The CEPY SAMs constrained the Faraday behavior of the hydrophilic K3[Fe(CN)6] on the gold electrode. Our studies indicated that the pyrrole moieties in CEPY SAMs could be oxidized, but the pyrrole rings could not orient parallel to the substrate due to the rigidity of the SAMs, which resulted in no-polymerization in the SAMs during electrochemical cycling.