HarvestGuard: An Eco-friendly Electrochemical Sensor for Precise Nitrate Detection in Soil Using Zinc Oxide Nanoparticles/PANI Composite Decorated Nickel Foam Electrode

This study focuses on technological innovations in the agriculture industry, specifically aiming to enhance soil macronutrient detection. A novel nanocomposite Ni-foam sensor electrode was developed for the efficient detection of nitrate (critical macronutrient) in soil. The fabrication of the nanocomposite electrode involved the synthesis of zinc oxide (ZnO) and polyaniline (PANI) nanocomposites using cyclic voltammetry. Detailed analysis of the ZnO/PANI nanocomposite's morphological, elemental, and crystalline properties was conducted using  Field  Emission  Scanning  Electron  Microscopy (FESEM) and Energy Dispersive Spectroscopy (EDS). To evaluate the sensing performance, the ZnO/PANI nanocomposite Ni-foam electrode was analyse using square wave voltammetry. Experimental results demonstrated a direct linear relationship between the peak current and nitrate concentration, highlighting the sensor's efficiency in detecting nitrate. Notably, the developed sensor exhibited a high sensitivity of 31 µA/µM and a remarkably low detection limit of 0.40 µM, underscoring its exceptional accuracy and sensitivity in analyzing nitrate concentrations in soil samples.