Detection of Stress Induced by <i>Ganoderma boninense</i> Infection in Oil Palm Leaves Using Reduced Graphene Oxide and Zinc Oxide Nanoparticles Screen-Printed Carbon Electrode

Abstract

A modified carbon electrode has been successfully developed in this study using reduced graphene oxide (rGO) and zinc oxide nanoparticles (ZnO-NPs) as surface modifiers. This disposable modified screen-printed carbon electrode (SPCE) was fabricated to be used as a sensing material in order to detect stress in oil palms leaves induced by Ganoderma boninense (G. boninense) infection. The electrochemical signals received from the healthy and stress leaves crude extracts were studied using the differential pulse voltammetry (DPV) technique. The results showed that the ZnO-NPs/rGO/SPCE established a good correlation coefficient (R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) of stress leaves crude extracts at 14 and 30 days post-infection of G. boninense ( <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14I</sub> R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.9652 and <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">30I</sub> R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.9710) with a limit of detection (LOD) of 1.75 mg/L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14I</sub> and 3.23 mg/L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">30I</sub> , respectively.