Dye-doped organically modified silica glass for fluorescence based carbon dioxide gas detection

The sol–gel process was used to prepare organically modified silica glass in which the fluorescent pH-sensitive reagent 1-hydroxypyrene-3,6,8-trisulfonate is entrapped. An ion-pair approach was used to incorporate the hydrophilic dye in the hydrophobic glass. Good sensitivity to gas phase carbon dioxide was observed in the 0–20% range, with rapid response. A solid-state optical sensor device is described which could lead to thin film waveguide sensors suitable for mass production.