Tailoring colour changes of optical sensor materials by combining indicator and inert dyes and their use in sensor layers, textiles and non-wovens

The appropriate combination of absorbance-based indicator dyes and inert dyes allows colour changes from green to red to be observed. In detail, a pH indicator with a yellow to red colour change upon exposure to alkaline buffers is combined with a blue and pH-insensitive dye. The resulting colour change of indicator plus inert dye is more easily visible than the original colour change and is more easily interpreted in terms of a “traffic light”...