Electrostatic self-assembly of a ruthenium-based oxygen sensitive dye using polyion–dye interpolyelectrolyte formation

The dye tris(2,2′-bipyridyl dichlororuthenium) hexahydrate has been successfully applied to glass and silica surfaces using the technique of layer by layer self-assembly. Solutions of both admixed polyion–dye and pure dye were used to attempt adsorption of the dye onto the substrates. Characterization of the constructed dye layers was performed using quartz crystal microbalance (QCM), UV-Vis absorbance spectrophotometry, fluorescence spectroscopy, and scanning electron microscopy (SEM) methods. Successive, controlled addition of multiple dye layers has been demonstrated, and exposure to different levels of dissolved oxygen shows that the films containing entrapped dye molecules retain sensing properties.