ESA-based in-fiber nanocavity for hydrogen–peroxide detection

A fiber-optic sensor sensitive to hydrogen peroxide has been designed based on the electrostatic layer-by-layer selfassembly method. Prussian blue has been deposited in a polymeric structure formed by Poly(allylamine hydrochloride) and poly(acrylic acid). The concentration that can be detected range between 10 6–10 3 M, and recovery of the sensor after immersion into a reductive agent was demonstrated. The response of the sensor is independent of thepHfor values that range between 4–7.4. Some rules for estimation of the refractive index of the material deposited and the thickness of the bilayers are also presentedThis work was supported by Spanish CICYT Research Grants TIC 2003-00909 and TIC 2001-0877-C02- 02; Gobierno de Navarra and FPU MECD grant