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Proceedings Paper

Fluorescent porous sol-gel coatings for near-IR single-mode fiber chemical sensors
Author(s): Alexander J. Fielding; Christopher C. Davis
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Paper Abstract

Reports of enhanced photostability of organic florescent dyes when entrapped in a sol-gel matrix have led us to examine the behavior of the near-IR dye IR-125 coated onto the end of single mode optical fibers. Various fiber tip geometries were fabricated and a specially prepared rounded tip was found to be optimal for long-term adhesion of thick sol-gel coatings to the fiber. Fluorescence captured back into the fibers was measured over one month and different initial concentrations of dye were also examined. The porosity of sol-gel thin films has been explored in the past to fabricate pH, oxygen, and other enzyme-based sensors. We have tested the porosity of our coatings by showing a non- reversible pH sensitivity, however current data is insufficient to rule out the possibility of a structural change in the coating also effecting these results. Using the rounded tip geometry, eighty percent of our samples lasted over two months without cracking while still maintaining fluorescence activity. Exposed to air, the coated fibers were each able to be examined an average of 200 times with 20 microsecond(s) ec interrogation pulses of 1.5 mW from a 785 nm semiconductor laser diode before photobleaching reduced the resulting signal to background.

Paper Details

Date Published: 26 March 1998
PDF: 7 pages
Proc. SPIE 3258, Micro- and Nanofabricated Structures and Devices for Biomedical Environmental Applications, (26 March 1998); doi: 10.1117/12.304367
Show Author Affiliations
Alexander J. Fielding, Univ. of Maryland/College Park (United States)
Christopher C. Davis, Univ. of Maryland/College Park (United States)

Published in SPIE Proceedings Vol. 3258:
Micro- and Nanofabricated Structures and Devices for Biomedical Environmental Applications
Paul Lee Gourley, Editor(s)

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