MINIATURIZATION OF ORGANICALLY DOPED SOL-GEL MATERIALS - A MICRONS-SIZE FLUORESCENT PH SENSOR

Miniaturization of a reactive doped sol-gel material is described. A r eversible fluorescent pH sensor was constructed by placing a pyranine doped SiO2 sol-gel matrix at a 10 mu m tip of a metal coated micropipe tte. Subsecond response time was achieved by further downscaling to si milar to 1 mu m. Using optical near-field microscopy configuration, th ese observations demonstrate the potential of constructing a variety o f miniaturized sensors and chemical manipulators, by doping the sol-ge l matrix with a suitable reagent.