Design, Fabrication, and Optimization of Polypyrrole/Bismuth Oxide Nanocomposite as Voltammetric Sensor for the Electroanalysis of Clofazimine

Abstract

The highly sophisticated and conducting Polypyrrole/Bismuth Oxide nanocomposite material was designed, fabricated, characterized and optimized as a novel voltammetric sensor for the electroanalysis of clofazimine (CFZ). The designing and fabrication of voltammetric sensor were reached by the synthesis of Ppyl/Bi2O3 nanocomposite for the modification of glassy carbon electrode (GCE). Prior to the fabrication of Ppyl/Bi2O3/GCE sensor, the Ppyl/Bi2O3 nanocomposite material along with its constituents Ppyl and Bi2O3 were characterized by FTIR, XRD and scanning electron microscopy (SEM). The cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were used to determine the surface area, heterogeneous electron transfer (HET) rate constant and charge transfer resistance of the bare GCE and its other modified forms viz., Bi2O3/GCE, Ppyl/GCE including the Ppyl/Bi2O3/GCE sensor to confirm the successful fabrication by comparing their electrocatalytic activities toward the CFZ. The Ppyl/Bi2O3/GCE sensor after optimization in Britton-Robinson buffer of pH 2.5 in ethanol exhibited a well-defined reduction peak varying linearly over a concentration range of 21.12 μmol/mL to 253.49 μmol/mL with a correlation coefficient (r2) of 0.99. The designed sensor shows the highest sensitivity in terms of the limit of detection (LOD) and the limit of quantification (LOQ) found to be 0.97 μmol/mL and 3.23 μmol/mL respectively. The optimized sensor also reveals the exceptional reproducibility with a relative standard deviation (RSD) of 1.20%, satisfactory recovery of 100.04% to 103.20% and long-term stability.