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(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(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(2) particles (<5 microm 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(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.

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A water-soluble fluorescent probe was described for detecting hydrogen peroxide with the carbazole-derived as fluorophore and boronate moiety as recognition unit. The probe was developed as a turn-off fluorescent chemosensor with fast, high selectivity and sensitivity toward H2O2over other biological reactive oxygen species. What is more, the probe was quenched linear response to H2O2concentration in the range of 1.0×10−8- 2.0×10−5M and lower detection limit down to 6 nM (S / N = 3) was obtained.

A water-soluble fluorescent probe was described for detecting hydrogen peroxide with the naphthalimide derived as fluorophore and boronate moiety as recognition unit. The probe was developed as a turn-on fluorescent chemosensor with fast, high selectivity and sensitivity toward H2O2over other biological reactive oxygen species. What is more, the probe was linear response to H2O2concentration in the range of 2.5×10−8– 3.2×10−5M and lower detection limit down to 12 nM (S / N = 3) was obtained.