Electrochemical Sensing of Paracetamol Using Functionalized MWCNTs: Integrating Computational and Experimental Methods

Abstract

An electrochemical sensing platform for the detection of paracetamol is proposed in this work. The sensor (Asp‐MWCNTs/IL/ITO) is based on Indium Tin Oxide (ITO) electrode loaded with asparagine functionalised Multi Walled Carbon Nanotubes (MWCNTs) and Ionic Liquid (IL). Initially, in‐silico studies were performed to check the favourable interaction of the drug with the nanocomposite. The potential energy surface of Asp‐MWCNTs and paracetamol complexes were explored using density functional theory and single‐point energy coupled cluster calculations. The analysis of non‐covalent interactions showed hydrogen bonding interactions predominantly stabilising the complex. The interaction process between Asp‐MWCNTs and paracetamol is spontaneous due to negative value of binding energy (‐0.75 eV). The functionalised MWCNTs were characterised through different techniques. Asp‐MWCNTs/IL/ITO electrode showed good sensitivity with a linear range from 20 – 300 μgL−1 and limit of detection of 0.0194 μM for paracetamol in phosphate buffer as supporting electrolyte. The sensor showed excellent repeatability and reproducibility with a relative standard deviation of 1.45% at 60 μgL−1 concentration. The chemical functionalization resulted in providing extra stability as it retained 95% of its signal response even after 45 days. The sensor’s applicability was tested in real water samples with the help of spiking study which showed good recovery >95%.”