Confocal microscopy for characterization of porous sol-gel glasses incorporating luminescent dyes

Porous glasses were prepared using the sol-gel method. The mix of catalysts used during preparation was changed in order to produce two glasses with two different densities. Fluorescent dyes were incorporated into these glasses by diffusion into the glass. The resulting fluorescent glasses were characterized using confocal microscopy, which allows thin optical sections to be imaged at up to 200 μm below the sample surface. In addition, fluorescence recovery after photobleaching (FRAP) was used to demonstrate diffusion of the dye within wet samples. The results demonstrate the potential for non-invasive optical characterization of fluorescent sol-gel glasses, and in particular local measurement of diffusion coefficients within the glass matrix.