Electrodeposition of Copper Thin Films on Screen Printed Carbon Electrodes towards Electrochemical Sensing of Nitrate

Abstract

Accurate and frequent monitoring of NO3 − levels in water bodies is crucial for human health and environment. In this work, copper (Cu) thin films electrodeposited on screen-printed carbon electrodes (SPCEs) were explored as an electrochemical sensing platform for the detection of NO3 − in water. Scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS) was employed to characterize the morphology and composition of the thin film modified electrode. The electrochemical response of Cu thin film deposited SPCE under different pH conditions (4 to 10) and various temperature (20 °C–60 °C) was assessed using linear sweep voltammetry (LSV). The developed electrochemical sensor allowed the measurement of NO3 − levels ranging from 50 to 750 μM with a sensitivity of 0.1042 μA mM−1. The sensor exhibited good detection limit in fish culture water (120 nM), reverse osmosis processed water (91 nM) and borewell water (98 nM). The sensor response was found to be stable in the presence of other interfering analytes (NO2 −, K+, Na+, SO4 2−, Mg2+, Cl-, Fe3+, Fe2+, Mn2+, Cu2+, Zn2+). The performance of the sensor was demonstrated in water samples collected from various sources and the sensor showed an acceptable performance rates for practical applications.