Macrolide-Selective Electrochemical Sensor Built from Dual-Functional Molecularly Imprinted Polymer

This work demonstrates the determination of macrolide antibiotics in aqueous environments using a screen-printed electrode (SPE) combined with a molecularly imprinted polymer (MIP) prepared from dual functional monomers. By employing the reversible covalent interactions between diols of macrolide and boronic acids of 3-aminophenylboronic acid (APBA) as well as the noncovalent interactions between macrolide and m-phenylenediamine (mPD), a dual recognition involving the central macrocyclic lactone exclusive to all macrolides was successfully achieved, thus permitting the possible broad recognition of individual members of the class. The prepared macrolide MIP (mMIP) was characterised by electrochemical and ellipsometric measurements. Following optimization, the sensor demonstrated about four times better recognition for macrolides, including erythromycin (Ery), clarithromycin (Cla), and azithromycin (Azi), than its non-imprinted reference. In addition, low analytical limits were achieved (LOD 1.1 - 1.6 nM and LOQ 3.8 - 5.3 nM). Moreover, an excellent selectivity was displayed towards the macrolides in both buffer and tap water samples, and a good recovery (93-108%) of the analytes was achieved. The analytical approach described herein could be further developed as a portable sensing device capable of on-site monitoring of macrolides in environmental water.