Voltammetric and Impedimetric Detection of Norfloxacin at Co Nanoparticle Modified Polymer Composite Electrodes

Abstract

AbstractThe measurement of antibiotics in environmental water systems is increasingly becoming a top priority for global environmental watchdog organisations, as the looming threat of emerging contaminants moves to centre stage. A novel chemical sensor based on polyamic acid (PAA) semiconducting polymer and cobalt nanoparticles (CoNP) was developed and used to demonstrate proof of concept evidence for measurement of norfloxacin at trace concentrations in aqueous systems. Polyamic acid and cobalt nanoparticles were both chemically synthesised and characterised using Fourier transform infrared spectroscopy, transmission electron microscopy, cyclic voltammetry and small angle x‐ray scattering. The polyamic acid and cobalt nanoparticles were electrodeposited onto screen printed carbon electrodes to produce novel composite sensors (SPCE/PAA/CoNP). The polymer composite chemical sensors were applied to the detection of norfloxacin in the micromolar concentration using square wave voltammetry, with a sensitivity of 18.0±6.59 μA/mM, calculated from the slope of the calibration curve and a limit of detection (LOD) of 0.979 ±0.419 mM, with LOD=3.3(Sy/S). The SPCE/PAA/CoNP sensor response to norfloxacin as measured by electrochemical impedance spectroscopy, yielded a sensitivity of 17.6±8.72 Ω/mM as and a limit of detection (LOD) of 0.228±0.0935 mM.