Electrochemical Determination of Bromate in Different Types of Flour and Bread by a Sensitive Amperometric Sensor Based on Palladium Nanoparticles/Graphene Oxide Nanosheets

Abstract

In the present work, a novel amperometric sensor for bromate detection and determination based on palladium nanoparticles supported by graphene oxide nanosheets (PdNPs-GO) modified glassy carbon (GC) electrode was fabricated. The graphene nanosheets were functionalized using a novel method, and palladium nanoparticles were synthesized by electrodeposition method. The surface morphology of modified electrodes was investigated using scanning electron microscopy (SEM). Determination and investigation of electrochemical parameters of bromate reduction were performed using rotating disk electrode (RDE) amperometry and cyclic voltammetry (CV) methods, respectively. The experimental data showed that PdNPs-GO/GC electrode has significant electrocatalytic activity toward bromate reduction. A wide concentration range (1–10 μM and 10–1,000 μM) with a good detection limit (1.05 × 10−7 M) were achieved. Also, this sensor has a short response time (15 s) and its sensitivity is 7.428 A/Mcm2. The accuracy of the proposed method was investigated by recovery experiments in different flour and bread samples where good recoveries were obtained (between 94 and 110 %). Furthermore, this electrode exhibited remarkable stability, repeatability, and selectivity.