Direct Electrochemical Determination of Glyphosate Herbicide Using a Screen-Printed Carbon Electrode Modified with Carbon Black and Niobium Nanoparticles

Glyphosate is a herbicide that has been widely used worldwide and is used in agricultural areas to control weeds and unwanted vegetation.Electrochemical sensors developed from different nanomaterials have high efficiency,excellent cost-benefit,and fast analysis time for detecting traces of environmental pollutants.This study aimed to produce an electrochemical sensor with disposable screen-printed electrodes based on carbon black modified with niobium nanoparticles to determine glyphosate in aqueous solutions.The morphology, structure and electrochemical performance of the sensor were characterized by scanning electron microscopy,energy-dispersive X-ray spectroscopy,X-ray diffraction and cyclic voltammetry.Differential pulse voltammetry in BR buffer solution at pH 5.0 allowed the generation of a method to quantify glyphosate concentration in a linear range of 5.90-172.30 μmol/L(1.00-29.13 μg/mL),with a limit of detection calculated at 3.07 μmol/L(0.52 μg/mL).The method efficiently quantified glyphosate in real water samples and showed no interference from K+,Na+,Ca2+,Mg2+ions or thiamethoxam,imidacloprid and carbendazim pesticides.