Electrofluorochromism of Surface-Confined Tetrazines Investigated on the Monolayer Scale

Monolayers of tetrazine-terminated alkyl chains have been grafted on indium tin oxide through siloxane functions. These monolayers are electroactive and display fluorescence with a maximum close to 560 nm when excited in the visible range. Potential step cycles have been applied, and the fluorescence intensity drawn from background- and bleaching-corrected emission spectra was found to be switched off and on reversibly according to the applied potential. This demonstrates that the luminescence of grafted fluorophores can be electrochemically controlled as it is in solution, and the emission intensity can be followed with a good signal-to-noise ratio even for a monolayer.