Porous glaxss substrates with potential applications to fiber optic chemical sensors

Porous glass (PG), used in fiber optical chemical sensors as a support for the sensitive reagent, was investigated. Microanalysis was employed to assess the effect of certain reaction parameters on the efficiency of each of the two steps involved in immobilizing an appropriate fluorescent dye onto the glass surface. It was found that the low organic content of the derivatized samples limits the overall usefulness of this analytical approach. The effect of various treatments was investigated and the fluorescence response of the derivative porous glass, both dry and in solution, was recorded. The fiber optic configuration used in the investigation resulted in strong fluorescence signals but a less-than-optimal response time. Generally, it was found that the fluorescence intensity of the dry PG was greater when lower concentrations of the fluorescent agent, fluorescent isothiocyanate (FITC), was employed in the immoblization step.