Design of an MIP-Based Electrochemical Sensor for the Determination of Paracetamol in Pharmaceutical Samples

Paracetamol (PAR) is a common antipyretic and analgesic extensively used to treat cold and flu symptoms. It has been proven to be effective in headaches and relieving fever and pain. It is usually found as an over-the-counter drug, which has been associated with an increase in cases of poisoning due to overdose. Therefore, the development of new analytical tools for the detection of PAR at low concentrations in different samples is necessary. In this work, a Molecularly Imprinted Polymer (MIP)-based electrochemical sensor was designed for the selective and sensitive determination of PAR using a glassy carbon electrode (GCE) modified with a polymeric film obtained through the electropolymerization of o-aminophenol. A complete characterization based on electrochemical techniques, such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and scanning electron microscopy (SEM) was used to examine all steps involved in the construction of the MIP-based electrochemical sensor. In addition, all parameters affecting the MIP were optimized. As a result, the MIP-based electrochemical sensor showed a very low limit of detection (LOD) of 10 nM, with an analytical sensitivity of (3.4 ± 0.1) A M⁻¹. In addition, construction of the MIP-based electrochemical sensor showed highly reproducibility, expressed in terms of a variation coefficient lower than 4%. The MIP-based electrochemical sensor was successfully used in an assay for the determination of PAR in pharmaceutical products. The performance of the MIP-based electrochemical sensor was compared to High Performance Liquid Chromatography (HPLC) for the determination of PAR in pharmaceutical samples, showing excellent agreement between the two methodologies. A very important aspect of the developed sensor was its reusability for at least twenty times. The MIP-based electrochemical sensor is a reliable analytical tool for the determination of PAR.