Plasticizer-free polymer membrane potentiometric sensors based on molecularly imprinted polymers for determination of neutral phenols

Abstract

Polymeric membrane potentiometric sensors based on molecularly imprinted polymers (MIPs) as the receptors have been successfully developed for detection of organic and biological species. However, it should be noted that all of the polymeric membrane matrices of these sensors developed so far are the plasticized poly(vinyl chloride) (PVC) membranes, which are usually suffered from undesired plasticizer leaching. Hence, for the first time, we describe a novel plasticizer-free MIP-based potentiometric sensor. A new copolymer, methyl methacrylate and 2-ethylhexyl acrylate (MMA-2-EHA), is synthesized and used as the sensing membrane matrix. By using neutral bisphenol A (BPA) as a model, the proposed plasticizer-free MIP sensor shows an excellent sensitivity and a good selectivity with a detection limit of 32 nM. Additionally, the proposed MMA-2-EHA-based MIP membrane exhibits lower cytotoxicity, higher hydrophobicity and better MIP dispersion ability compared to the classical plasticized PVC-based MIP sensing membrane. We believed that the new copolymer membrane-based MIP sensor can provide an appealing substitute for the traditional PVC membrane sensor in the development of polymeric membrane-based electrochemical and optical MIP sensors.