Self-assembled monolayers of 3-dodecylthiophene (DT), poly(3-dodecylthiophene) (PDT) and PDT-DT on gold electrodes are examined by ellipsometric, contact angle goniometric and electrochemical techniques. Potential cycling of the mixed monolayer of PDT-DT removes DT in the monolayer which leads to voltammetric responses at the electrode resembling those of ultramicroelectrode ensembles. The voltammetric characteristics of these ultramicroelectrode ensembles agree well with predictions of the relevant theories. The self-assembled PDT monolayers exhibit better thermal stability in wet environments than monomeric monolayers, suggesting that multi-anchoring effects of the polymer improve the integrated adhesion and the binding stability of the monolayers.