SOL-GEL-DERIVED MICRON SCALE OPTICAL FIBERS FOR CHEMICAL SENSING

We report for the first time on the preparation of organically-doped r oom temperature processed sol-gel-derived micron scale optical fibers as platforms for chemical- and bio-sensors. Micron scale optical fiber s are drawn from fluorescent dye-doped tetraethoxysilane (TEOS)-derive d sol-gel solution processed under ambient conditions. Such a simple m ethodology to entrap organic and even bioactive species within the opt ical fiber offers many advantages over more conventional ways of immob ilizing organic probes for the development of optical sensors. Specifi cally, we report on the photophysical properties of fluorescein (a pH sensitive fluorescent dye) and rhodamine 6G (R6G; laser dye) entrapped within sol-gel-derived optical fibers. We present the preliminary res ults on the viability of such doped optical fibers for chemical sensin g. Our results demonstrate that a fluorescein-doped sol-gel-derived op tical fiber responds to ammonia and acid vapors with a response time o f 1-2 seconds.