Explosives detection by fluorescence quenching of conjugated polymers in suspended core optical fibers

Abstract

In this work we demonstrate a suspended core microstructured optical fiber-based sensor platform forexplosives detection based on the fluorescence quenching of a surface-attached conjugated polymerpoly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). These fibers allow for strongevanescent field interactions with the surrounding media because of their small core size, and can sam-ple minute liquid volumes. This is the first demonstration of a fluorescent conjugated polymer sensorcapable of measuring liquid explosives samples loaded within an optical fiber. This technique is used toidentify 1,4-dinitrobenzene (DNB), a member of the nitroaromatics family of explosives, in acetone forconcentrations as low as 6.3 ppm in a total sampling volume of 27 nl and to quantify its concentrationusing the fluorescence decay lifetime, requiring an analysis time of only a few minutes.