An electrochemical sensor for paracetamol based on an electropolymerized molecularly imprinted o-phenylenediamine film on a multi-walled carbon nanotube modified glassy carbon electrode

Abstract

An electrochemical sensor combining a molecularly imprinted technique and an electropolymerization method is developed in this work. A molecularly imprinted polymer film was fabricated by electropolymerizing o-phenylenediamine in the presence of paracetamol after depositing carboxyl functionalized multi-walled carbon nanotubes onto a glassy carbon electrode surface. The template can be quickly removed in 50% ethanol. The molecularly imprinted sensor was tested in the presence or absence of paracetamol by cyclic voltammetry and linear sweep voltammetry to characterize the constructed sensor. The molecularly imprinted polymer based sensor displayed an excellent recognition capacity toward paracetamol compared with other structurally similar molecules. Additionally, the linear sweep voltammetry peak current was linear to the concentration of the analyte in the range of 2.0 × 10⁻⁷ to 4.0 × 10⁻⁵ mol L⁻¹, with a detection limit of 5.0 × 10⁻⁸ mol L⁻¹. The prepared sensor also showed stable repeatability and regeneration capacity. The sensor was applied to the determination of paracetamol in real samples successfully, with the recoveries ranging from 94% to 105%.