A Simple and Low-Cost Optical Fiber Intensity-Based Configuration for Perfluorinated Compounds in Water Solution.

We present a very simple approach for the detection of the Perfluorinated Alkylated Substances (PFAs) in water solution. Perfluorooctanesulfonate (PFOS) and Perfluorooctanoate (PFOA) are the most extensively investigated perfluoroalkyl and polyfluoroalkyl substances in water because human exposition can occur through different pathways, even if the dietary intake seems to be their main route of exposure. The developed sensor is based on a specific Molecularly Imprinted Polymer (MIP) receptor deposited on a simple D-shaped Plastic Optical Fiber (POF) platform. This novel chemical sensor has been characterized using a very simple and low-cost experimental setup based on an LED and two photodetectors. This optical sensor system is an alternative method to monitor the presence of contaminants with an MIP receptor, instead of a surface plasmon resonance (SPR) sensor in D-shaped POFs. For the sake of comparison, the results obtained exploiting the same MIP for PFAs on a classic SPR-POF sensor have been reported. The experimental results have shown that the actual limit of detection of this new configuration was about 0.5 ppb. It is similar to the one obtained by the configuration based on an SPR-POF with the same MIP receptor.