Progress in the understanding of tyramine electropolymerisation mechanism

Abstract

The potentiodynamic electrosynthesis of polyty- ramine (PTy) from acidic medium is analysed on the basis of the information collected by coupling cyclic voltam- metry and electrochemical quartz crystal microbalance (EQCM), ellipsometry and atomic force microscopy (AFM). The experimental results consistently indicate that different stages must be considered in a description of the polymerisation process, the first involving the formation of a poor-conducting, thin, smooth and homogeneous layer; at a later stage deposition kinetics change and eventually a nonplanar thick film is produced. A tentative polymerisa- tion mechanism is proposed, which finds support on the ab initio calculations carried out to predict the reactive sites for tyramine (Ty) oxidation and polymer growth.