Electrochemical monitoring of isoproturon herbicide using NiO/V2O5/rGO/GCE

The excessive exploitation of herbicides in crops pose lethal effects on the environment that causes several serious health issues in human and severely affects the aquatic life. The herbicide such as isoproturon is an organic compound which is broadly used to kill the weeds and increase crop yield. Beside this, it highly increases risk of toxicity in the environment, thus quantification of isoproturon through a reliable method is of great importance. To tackle out this issue a new electrochemical sensor based on NiO/V 2 O 5 /rGO nanocomposite was constructed to determine low level concentration of isoproturon in the vegetable samples. The characterization of NiO/V 2 O 5 /rGO nanocomposite was conducted through different advanced tools i.e. XRD, FTIR, AFM, EDX mapping, SEM and TEM. The XRD and FTIR confirmed exceptional crystalline nature and surface functionalities of nanocomposite while AFM evaluated 1.7 nm average size of nanocomposite. The close elemental mapping confirmed the presence of Ni, V, C and O atoms. SEM and TEM analysis successfully examined the morphology and 2D texture of NiO/V 2 O 5 /rGO nanocomposite. The electrocatalytic properties and conductive nature of proposed sensor was investigated through Tafel plot and cyclic voltammetry. For the low-level quantification of isoproturon, different parameters were optimized as scan sweep 150 mV/s, PBS electrolyte with pH 4 and potential window from 0.2 to 1.1 V. Under the linear concentration range from 0.009 to 30 µM, the fabricated sensor manifested low limit of detection found as 0.005 µM. The engineered NiO/V 2 O 5 /rGO/GCE exhibited anti-interference profile and long-term stability to be used for monitoring of herbicide for several days. The analytical application of developed sensor was tested in different vegetable samples where NiO/V 2 O 5 /rGO/GCE showed excellent recovery values.