An Optical Fiber ${\rm H}_{2}{\rm O}_{2}$ -Sensing Probe Using a Titanium(IV) Oxyacetylacetonate Immobilized Nafion Coating on an Bent Optical Fiber Probe

An optical fiber sensor technique has been developed for monitoring trace H₂O₂ in aqueous solutions. A titanium(IV) oxyacetylacetonate doped Nafion coating on the surface of a bent optical fiber probe was used as a transducer. Trace H₂O₂ in an aqueous solution diffused into the polymer coating reacts with the sensing agent. The resulted product absorbs light with peak absorption wavelength at 360 nm, which is detected by using optical fiber evanescent wave absorption spectrometry. This sensor reversibly responses to trace H₂O₂ in water, and has a detection limit (3σ) of 7.4_*10^-8 mole H₂O₂/L. This fiber-optic sensor is immune of interferences from electromagnetic field which makes it useful in proton exchange membrane fuel cell researches.