Electrochemical switching of chromogenic monolayers self-assembled on transparent platinum electrodes

The electrochemical switching of chromogenic monolayers, which were self-assembled on ultrathin platinum working electrodes, was investigated. The monolayers were prepared by maintaining the transparent platinum electrodes in either methanol solutions of thioether for 24 h or methanol/chloroform solutions of thiol for 1 h. The high transmittance of the monolayers in the visible region permitted the spectroscopic interrogation of a single layer of chemisorbed chromophores in transmission mode. Under these conditions, the absorbance of an electroactive and chromogenic self-assembled monolayers could be switched reversibly by addressing the platinum substrates with appropriate voltage stimulations.