Design of an Electrochemical Sensor Using 2D Sheet-Like Cu@g-C3N4 Transducer Matrix for Electroanalysis of Catechol

Abstract

The work illustrates the development of an electrochemical sensor for quantification of catechol (CTL) by modifying the pencil graphite electrode (PGE) with copper-doped graphitic carbon nitride (Cu@g-C3N4) nanosheets. The sheet-like graphitic carbon nitride (g-C3N4) wa synthesized by pyrolysis of urea, which was further doped with metallic copper to obtain Cu@g-C3N4. The synthesized Cu@g-C3N4 was characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy. The Cu@g-C3N4 suspension was drop-cast onto PGE to constitute PGE/Cu@g-C3N4 working electrode. The developed electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy and further employed for detection and quantification of CTL. The electrochemical investigation of the developed sensor showed enhanced activity toward electro-oxidation of CTL. Differential pulse voltammetry studies revealed superior sensor characteristics such as sensitivity (0.1487 μA μM−1 cm−1), selectivity, broad linear range (100–900 μM), and limit of detection (LOD) (15.12 μM). The study benchmarks the use of Cu@g-C3N4 as an excellent transducer material in electrochemical sensing of CTL in tea and standard samples, thus proving its potential application in the analysis of CTL in food and environmental samples.