Sol-gel clad fiber-optic waveguides are investigated as intrinsic distributed fiber-optic chemical sensors. The porous sol-gel cladding allows diffusion of analytes into the evanescent field region close to the fiber-optic core. Pulsed optical excitation (0.5 ns) and time-resolved emission detection can be used to simultaneously monitor several multiplexed sensor clad regions along a single optical fiber. Time-resolved detection is also demonstrated as a means of resolving both the spatial location and the fluorescence kinetics of intrinsic sensor chromophores along the fiber-optic waveguide. Narrow band excitation and spectrally resolved emission provide additional experimental means for discriminating between specific sensor clad regions. A fluorescein-doped silica xerogel clad pH sensor and an undoped aluminosilica xerogel clad quinone sensor are demonstrated as intrinsic sol-gel clad fiber-optic sensors.Fiber-optic chemical sensors provide an efficient and inexpensive method for selective, in situ, real-time chemical sensing. [1][2][3][4] The active sensor region of a fiber can be either immobilized at the distal end of an optical fiber (extrinsic) 2,5 or distributed along the length of the fiber-optic waveguide (intrinsic). 6,7 Submicrometer sized extensive fiber-optic sensors have also been reported, 8
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.