Design of Electrochemically Modified fMWCNT‐pencil Graphite Electrode Decorated with Cu and Ag Nanofilm and its Electrocatalytic Behavior Towards Imazethapyr

Abstract

Herein, a facile procedure was developed for designing an electrochemical sensor based on pencil graphite electrode modified with electrochemically synthesized silver and copper nanoparticles (AgNP and CuNP) supported on functionalized multiwalled carbon nanotubes (fMWCNTs). The electrochemical and morphological characterization was carried out by cyclic voltammetry, Electrochemical Impedance Spectroscopy, Powder X‐ray diffraction, Field Emission Scanning Electron Microscopy, Transmission electron microscopy and Atomic Force Microscopy. The designed sensor exhibited electrocatalytic behavior towards the reduction of Imazethapyr. Results indicates the combination of AgNPs, CuNPs and fMWCNTs on PGE produced remarkable enhancement in electrocatalytic and sensing properties. Various electro‐kinetic parameters like Rct, kapp, n, α, E0, k0, Γ, D and k have been evaluated by CV, impedance and Chronoamperometric studies. The electrochemical performance was improved by optimizing the effect of pH, scan rate, amount of fMWCNTs and deposition parameters of AgNP and CuNP. The sensor was efficaciously applied for determination of Imazethapyr and exhibited a linear correlation in the concentration range of 0.01–5.0 μg mL−1 with low detection limits, 0.159 ng mL−1 using AdSWV. The fabricated sensor exhibited good accuracy, acceptable stability and high efficacy for quantitative determination of Imazethapyr in real samples with notable recoveries ranging from 98 % to 100.2 %.

Development of a Novel Molecularly Imprinted Polyvinylimidazole/Functionalized Carbon Black Nanocomposite‐based Paste Electrode for Electrochemical Sensing of Imazethapyr in Rice Samples

“…This result is confirmed by the mechanism proposed by Khan et al. [19], where two protons and two electrons are involved (Scheme 1).…”

“…Initially, the MIP- based sensors were prepared at 50 : 45 : 5 (w/w %) ratio of CB or fCB:mineral oil:MIP, and the non-MIP-based sensors at 50 : 50 (w/w %) ratio of CB or fCB: mineral oil. As shown in Figure 3, IMT exhibits an irreversible cathodic peak (Epc) at À 0.80 V for CB [18,19], while for MIP-CB, the IMT reduction is observed at À 0.89 V with an increase in the cathodic peak current (Ipc) intensity. Such outcome can be explained by the interactions between the selective MIP cavity with the analyte, resulting in greater adsorption of IMT on the electrode surface.…”

“…Electroanalytical techniques are an important tool for monitoring compounds of environmental interest through a simpler approach, presenting low detection limits, low instrumental cost, and portability [17]. Few studies in the literature explore the determination of IMT by these techniques [18, 19]. Pintado et al.…”

“…Electroanalytical techniques are an important tool for monitoring compounds of environmental interest through a simpler approach, presenting low detection limits, low instrumental cost, and portability [17]. Few studies in the literature explore the determination of IMT by these techniques [18,19]. Pintado et al [18], evaluated the voltammetric behavior of the imidazolinone herbicides using carbon and mercury electrodes, showing that unmodified electrodes present low performance for IMT determination.…”

Electroanalysis of an Iron@Graphene‐Carbon Nanotube Hybrid Material

“…In the Randles equivalent circuit model R ct and CPE are placed in parallel and represent the electrode impedance . The semicircle part from the Nyquist plot corresponds to R ct and R s at lower frequencies; and the linear part, at higher frequencies, corresponds to the diffusion process at the modified and bare SPCE, respectively. The lower semicircle from MWCNT‐0.5‐modified SPCE respect to that from other concentrations of modified materials and to the bare SPCE indicate the lower resistance that the material is offering to the current pass.…”