Fluorescent Dye-doped Sol-gel Sensor for Highly Sensitive Carbon Dioxide Gas Detection below Atmospheric Concentrations
- University of Tennessee, Knoxville (UTK)
- ORNL
- InnoSense Incorporates
- NASA Stennis Space Center
Optical fluorescence sol-gel sensors have been developed for the detection of carbon dioxide gas in the 0.03?30% range with a detection limit of 0.008% (or 80 ppm) and a quantitation limit of 0.02% (or 200 ppm) CO{sub 2}. Sol?gels were spin-coated on glass slides to create an organically modified silica-doped matrix with the 1-hydroxypyrene-3,6,8-trisulfonate (HPTS) fluorescent indicator. The luminescence intensity of the HPTS indicator (513 nm) is quenched by CO{sub 2}, which protonates the anionic form of HPTS. An ion pair technique was used to incorporate the lipophilic dye into the hydrophilic sol?gel matrix. TiO{sub 2} particles (<5 {mu}m diameter) were added to induce Mie scattering and increase the incident light interaction with the sensing film, thus increasing the signal-to-noise ratio. Moisture-proof overcoatings have been used to maintain a constant level of water inside the sensor films. The optical sensors are inexpensive to prepare and can be easily coupled to fiber optics for remote sensing capabilities. A fiber-optic bundle was used for the gas detection and shown to work as part of a multianalyte platform for simultaneous detection of multiple analytes. The studies reported here resulted in the development of sol?gel optical fluorescent sensors for CO{sub 2} gas with sensitivity below that in the atmosphere (ca. 387 ppm). These sensors are a complementary approach to current FT-IR measurements for real-time carbon dioxide detection in environmental applications.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 981781
- Journal Information:
- Analytical Chemistry, Vol. 82, Issue 2
- Country of Publication:
- United States
- Language:
- English
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