Optical chemical fiber sensor for the detection of perfluorinated compounds in water

In this work a novel Molecularly Imprinted Polymer (MIP) able to bind PFAs (Perfluorinated Alkylated Substances) contaminants in water, combined with a plasmonic optical fiber sensor, is presented. The advantage of an MIP receptor is that it presents a better stability out of the native environment, very good reproducibility, low cost and, furthermore, it can be directly deposited on the gold sensing layer, without modifying the metal surface by functionalizing procedures. PFOA (Perfluorooctanoate) and PFOS (Perfluorooctanesulfonate) are the most extensively investigated PFAs because human exposition can occur through different pathways, and the dietary intake seems to be their main route of exposure. The experimental results have shown that the developed optical chemical sensor makes it possible to detect the above compounds. Sensor's response is exactly the same for PFOA, PFOS or PFAs contaminants. The limit of detection (LOD) of the developed chemical sensor was about 0.2 ppb, a value that is lower than the maximum residue limit fixed by the European Union regulations. This optical chemical sensor could be used for remote sensing, taking advantage of the capability of the optical fiber.