Novel Halochromic Disazo Stilbene Dye with Intramolecular Color Mixing Effect for Textile Sensor Material

A stilbene-based halochromic dye was synthesized, which possesses the effect of intramolecular color matching. By dyeing cotton fabric with the synthesized dye, a textile sensor material was prepared to visually monitor the acidity of the biologically significant pH range (4.5–8.0). The sensitivity of the sensor material to changes in the acidity of the environment, as well as the color stability to the action of saline solutions simulating biological fluids (sweat and blood plasma), were explored. A visually noticeable pH-induced color change of the material is observed in the pH range of 3.0–10.0. In the pH range of buffer solutions at pH 3, the color of the samples is green, from 6 to 8, orange, and from 9 and above, purple. The average color change time was 3 s. The results obtained show the promise of using the studied azo compound in technologies for designing multifunctional pH-sensitive textile sensor materials.