A molecularly imprinted electrochemical sensor based on sol–gel technology and multiwalled carbon nanotubes–Nafion functional layer for determination of 2-nonylphenol in environmental samples

Abstract

In this work, we have proposed a sensitive and selective detection technique for 2-nonylphenol (2-NP) based on the differential pulse voltammetry at a molecularly imprinted film on a glassy carbon electrode (GCE). The imprinted film was immobilised on the GCE by electrodeposition of a molecularly imprinted polymer (MIP) sol–gel consisting of a multiwalled carbon nanotube (MWNT)–Nafion (NF) composite. The modification procedure was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). The recognition between MIP sol–gel film and target molecule was observed by measuring the change in DPV response of the oxidation-reduction probe, K3Fe(CN)6 on GCE. Under optimized operational conditions, a linear response was obtained covering the concentration range from 0.2 to 360μmolL−1 with a detection limit of 0.06μmolL−1. The proposed sensor was applied to 2-NP determination in water and soil samples with the recoveries from 95.4 to 98.1%, showing a promising potential application in environment samples. Additionally, The imprinted sensor demonstrated higher affinity for target 2-NP than that of non-imprinted polymer (NIP) sensor.