Electrochemical sensing of rifampicin in pharmaceutical samples using meso-tetrakis(4-hydroxyphenyl)porphyrinato cobalt(II) anchored carbon nanotubes

Abstract

In this work, an electrochemical sensing platform is prepared for rifampicin determination based on multiwalled carbon nanotubes (MWCNTs) modified with meso-tetrakis(4-hydroxyphenyl)porphyrinato cobalt(II) (CoTHPP) nanocomposite (abbreviated as MWCNTs-CoTHPP). The material is characterized by different techniques such as UV–Vis, Fourier transform-infrared, Raman, transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray analysis. For the electrochemical sensing platform, the nanocomposite, MWCNTs-CoTHPP is immobilized on glassy carbon (GC) electrode (represented as GC/MWCNTs-CoTHPP) and applied for electrochemical recognition of rifampicin. It is found that the GC/MWCNTs-CoTHPP electrode facilitates the electrochemical oxidation of rifampicin with decreased overpotential in 0.1 M acetate buffer (pH 4.7). Further, GC/MWCNTs-CoTHPP exhibits broad calibration range (0.01 µM–5.0 mM), high sensitivity (217 µA mM−1 cm−2), high reproducibility (relative standard deviation = 4.83%, n = 6), and low detection limit (0.008 µM) for rifampicin determination. In addition, this method is successfully applied for real sample (rifampicin capsule) analysis with consistent results. The results suggest that MWCNTs-CoTHPP is a potential candidate for an effective, rapid, and simple electrochemical sensor to detect rifampicin in pharmaceutical formulations.