Surface tempering of poly-(3 thiophene acetic acid) coated carbon fiber paper electrode with spine-like cobalt inorganic phosphate: An efficacious electrochemical metol sensor

Abstract

N-methyl-p-aminophenol sulfate (metol) is a photographic developing agent that has a toxic effect on humans and aquatic life. A cost-effective and sensitive electrochemical sensor was developed by electrodepositing Co-Pi over poly-(3 thiophene acetic acid) coated carbon fiber paper electrode (Co-Pi/PTAA/CFP) for the determination of metol (ML). Surface modification of Co-Pi facilitates superior electrocatalytic performance by offering more active sites and faster electron transport kinetics. The Physico-chemical characterization of the fabricated electrode was carried out by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) Field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy (EDS), Optical profilometer, Fourier transform infrared spectroscopy (FTIR), and electroanalytical techniques. The electrochemical studies were performed using Cyclic voltammetry (CV), Electron Impedance spectroscopy (EIS), and Differential pulse voltammetric (DPV). DPV studies revealed excellent sensing performance for ML, with a wide linear dynamic range of 6 nM to 800 nM, and a limit of detection (LOD) of 2 nM. A distinctive oxidative anodic peak was observed at 0.11 V indicating the excellent electrochemical performance of the electrode. The results suggested that the developed electrode exhibited good catalytic activity, selectivity, and sensitivity towards the electrochemical determination of ML. Further, the developed electrode was extended to its application in real samples obtained from lake water and domestic wastewater.