Novel Electrochemical Sensor for Rifampicin based on Ionic Liquid Functionalised TiO2 Nanoparticles

Aim: The main strategy of this study is to develop a novel ionic liquid functionalised metal nanocomposite based electrochemical sensor with potential applications for the sensitive electrochemical detection of rifampicin. Background: Tuberculosis (TB) is a widespread disease that is caused by the gram-positive Mycobacterium tuberculosis (MTB). In addition, for several decades TB has become a constant threat to human health, however due to the accessibility of broad-spectrum antibiotics (rifampicin, pyrazinamide, isoniazid, and ethambutol), which are active against the bacterium, the social and economic burden for sufferers from the illness remains to be huge. Specially, in countries, like India and sub Saharan Africa, it is one of the common diseases affecting members from all age groups. So, this work is aimed at developing a novel electrochemical sensor for the determination of rifampicin (RIF) in pharmaceutical samples. Objective: To synthesis and characterization of the novel liquid functionalised metal nanocomposite. Fabrication of glassy carbon electrode with potent electrode modifiers whose applicability as electro catalysis agents towards rifampicin is investigated. Method: In this work, a nanocomposite based on trihexyltetradecylphosphonium-bis-(2,4,4-trimethylpentyl)-phosphinate ([P14, 6, 6, 6] [(C8H17)2 PO2)]) ionic liquid functionalised titanium oxide nanoparticles (TiO2NPs) and multiwalled carbon nanotubes (MWCNTs) were used in the modification of a highly sensitive electrochemical sensor for quantification of rifampicin in pharmaceutical formulations. The modified glassy carbon electrode (GCE) were characterised by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Results: The electrochemical behaviour of RIF was studied on the modified electrode by the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. At pH 6.0 in phosphate buffer solution (PBS), the anodic peak current value of RIF obtained with the fabricated electrode is 7 times greater than with the bare GCE electrode. The anodic peak current value and concentration of RIF showed a good linear relationship in the range of 0.015–2.8 μM, with the limit of detection (LOD) of 0.0218 μM and limit of quantification (LOQ) 0.3120 μM respectively. Conclusion: Under the optimal conditions, the IL-f-TiO2NPs-MWCNTs-GCE provided a relatively lower detection limit and wider linear range compared to other previous procedures. The proposed electrochemical sensor had potent catalytic activity for RIF oxidation and provided important quantitatively reproducible analytical performance. Finally, this modified electrode was successfully applied to the determination of RIF in real pharmaceutical samples.