Oxygen gas optrode based on microstructured polymer optical fiber segment

In this article, we first propose a novel type of oxygen gas optrode by forming fluorophore doped sensing film in the array microholes with the characteristics of microstructured optical fiber (MOF) segment. Comparing with the conventional O2 detecting method, this slender shaped optrode shows potential in trace amount of O2 sensing and online O2 monitoring. Organical silicate gel or plastified cellulose acetate are chosen as sensing films and tris (4,7-diphenyl-1,10-phenathroline) ruthenium(II) dichloride ([Ru(dpp)3]Cl2) or meso-tetraphenylporphyin (TPP) as quenching fluorophores. From the experimental results, we find [Ru(dpp)3]2+–Gel–MOF optrode has favorable sensing characteristics, and the Stern–Volmer plots are linear in the full concentration range of O2 (0–100% v/v). The ratio of I0/I100, where I0 and I100 respectively represents the fluorescence intensities of the optrode exposed to 100% N2 and 100% O2, as a sensitivity of the optrode is 10.8. Simultaneously, the optrode can make a quick response within 50 ms.

Research Highlights
► Microstructured optical fiber (MOF) segment as the sensing optrode of oxygen gas.
► Sensing films has been fabricated in the MOF.
► The concentration of oxygen are determined by the fluorescence intensities.
► The ratio of I0/I100 as a sensitivity of the optrode is 10.8.