Preparation and properties of modified sol-gel sensing membrane for fiber optic oxygen sensor

Abstract

Modified sensing membranes based on fluorecence quenching were prepared by the sol-gel method, using formamide as the drying control chemical additive, tetraethoxysilane as the main material, Ru (phen)₃ Cl₂ as the indicator. The membrane with the optimum thickness of 20–50μm is uniform and crack-free, in which the indicator has a very small leaking rate. The membrane is immersed in water for 50h, the membrane sensing parameter M decreases by less than 5%. The fiber optic oxygen sensor with the sensing membrane has a detection limit of 5×10⁻⁶ M (ppm), a response time of less than 30s, excellent reproducibility and stability.

Keywords

sol-gel sensing membrane / drying control chemical additive / fiber optic oxygen sensor

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