Development of a novel optical sensing method for acid solution using Oil Red O supported by florisil

A novel field sensing method for concentrated acid solutions was developed. The sensor is composed of a dye, Oil Red O, and florisil as a support for the dye. When the dye is supported on the florisil surface, its color change properties against the acid solution drastically changes compared to in solution, and the sensor is applicable to sensing for acids of relatively low concentration. The significant phenomenon could not be observed when silica gel was used as a support, suggesting that the florisil plays an important role in the color changing phenomenon. The amount of dye absorbed on the florisil surface is related to the color change properties.