For the detection of chemical agents in different environments, the combination of plastic optical fibers (POFs) and molecularly imprinted polymers (MIPs) receptors has been tested as a way to obtain low cost, highly selective and sensitive optical chemical sensors based on plasmonic resonance. In this work, a novel type of optical chemical sensor able to detect the binding reactions occurring between the MIP and analyte has been designed, fabricated and applied for the selective detection of dibenzyl disulfide (DBDS) in transformer oil. This analyte is important in the control of transformer oil, since it is responsible for the corrosive properties of the oil. The new optical sensor platform is based on two plastic optical fibers that work as segmented waveguides coupled through a polymer molecularly imprinted for the analyte. The prepolymeric MIP solution was deposited by drop coating in a trench milled between the two fibers. The experimental results indicated that this new sensor can be useful for the determination of DBDS in transformer oil and it paves the way to a new approach in the optical fiber sensors for MIPs. (C) 2016 Elsevier B.V. All rights reserved.