Nanomolar determination of Penicillin G potassium (PGK) salt using a Carbon Paste Electrode modified with TiO2 nano particles /Ionic Liquids in real samples

Abstract In this work, a novel sensor based on a Carbon Ionic Liquid Electrode (CILE) and TiO2 Nano-Particles (NPs)/Ionic Liquid (IL) (octylpyridinium iodide) was introduced. We demonstrated the electrochemical behavior and applications of a Carbon Paste Electrode (CPE) modified with TiO2 NPs/IL (TiO2 NPs/CILE) for the determination of penicillin G potassium (PGK) at a pH value of 7.0 through Cyclic Voltammetry (CV) and Square-Wave Voltammetry (SWV) techniques. Characterization of this new sensor was performed by using different techniques, including Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). All the effective electrochemical parameters, such as pH, scan rate, step increment, frequency, and pulse amplitude, on PGK detection were studied. PGK showed a linear square-wave voltammetric response within the dynamic range of 3.0–1000.0 nM associated with the regression factor (R2) of 0.9940, Limit of Detection (LOD) of 2.09 nM, and Limit of Quantification (LOQ) of 6.95 nM. The practical applicability of TiO2 NPs/ILCE was examined by evaluating PGK detection in milk, pharmaceutical formulations, and biological samples, which resulted in satisfied recoveries.