Measurement of MIPs Responses Deposited on Two SPR-POF Sensors Realized by Different Photoresist Buffer Layers

We have used the same biomimetic receptor, a specific molecularly imprinted polymer (MIP), on two different plasmonic plastic optical fiber (POF) sensors to measure how the optical response influences the chemical response. To obtain two surface plasmon resonance (SPR) platforms, we have used two different overlayers between the core of the POF and the gold film. These overlayers, with a refractive index higher than that of the POF's core [poly(methyl methacrylate) (PMMA)], have been used to improve the performances of the plasmonic sensor. As overlayers, we have deposited a photoresist (Microposit S1813), in two different aging conditions, namely, before and after its expiry date. In this article, we have demonstrated how the alteration in the photoresist changes the sensor's performances and eventually the chemical response of the MIPs. More specifically, we have compared the MIPs responses of these two SPR-POF platforms in two different refractive index ranges. For this purpose, an MIP receptor already tested in the detection of perfluorinated compounds (PFAs) in water has been exploited.