Detection Range Setting via Electropolymerization of Molecularly Imprinted Polymers With Plasmonic Optical Fiber Probes – The Case Study of Caffeine as a Small Molecule

In this work, by exploiting in situ electropolymerization of molecularly imprinted polymer (eMIP) layers over surface plasmon resonance (SPR) optical fiber probes, the capability to extend the analyte detection concentration range by tuning eMIP layer thickness is demonstrated. More specifically, in this proof‐of‐concept sensing strategy, the caffeine was used as a template in order to evaluate the responses of the sensors in the detection of a small molecule. Two sensor configurations are designed, developed, and tested exploiting two eMIP layers with different thicknesses combined with the same SPR plastic optical fiber (POF) platform. The experimental results demonstrated that two detection ranges, in the femtomolar and picomolar ranges, were achieved using the developed sensor configurations. Moreover, the developed SPR‐POF‐eMIP sensors offer several advantages, including high selectivity, a fast response time (about 10 min), the intrinsic versatility of eMIP coding, small‐size and low‐cost sensor chips, and a portable and simple setup (reader).