Biosynthesis of α-Fe2O3-CdO Nanocomposites for Electrochemical Detection of Chloridazon Herbicide

Biosynthesised α-Fe2O3-CdO electrochemical nanosensor attained from Coriandrum sativum leaves extract and fabricated on the screen-printed electrode to detect chloridazon (CLZ) herbicide in agricultural food samples. Scanning electron microscopy, energy dispersive x-ray analysis, X-ray diffraction spectroscopy, cyclic voltammetry, and differential pulse voltammetry were used to investigate the α-Fe2O3-CdO electrochemical nanosensor. The optimization factors of the effect of pH, accumulation time, accumulation potential, and foreign substances were elevated. The α-Fe2O3-CdO/SPE electrochemical nanosensor shows the significant voltammetric response for the CLZ detection. Foreign substances did not considerably influence pesticide detection. Dynamic linear CLZ plot for a standard solution of CLZ was obtained in the concentration range of 0.1 to 36.00 µg⸳mL-1 (R=0.995) with a limit of detection 0.059 µg⸳mL-1 and a quantification limit of 0.179 µg⸳mL-1. The proposed electrochemical nanosensor was used to detect CLZ in agricultural food samples and agreeable recovery results.

A modified sensitive palladium-copper oxide and multiwalled carbon nanotubes electrochemical sensor for detection of ametridione pesticide

Glassy carbon electrode modified sensitive Pd-CuO/MWCNTs electrochemical nanosensor was used for detection of ametridione pesticide in water samples. The morphology characteristics of Pd-CuO/MWCNTs are examined by scanning electron microscopy and EDX. The ametridione pesticide under voltammetric investigation involves irreversible, 4e? electron reduction based on the protonation of the two carbonyl groups (>C=O). The voltammetric method was applied for the detection of ametridione in BR buffer solution at pH 5.0 as a supporting electrolyte. The detection limit, limit of quantification and concentration ranges of the proposed method were 0.0796 ?g?mL?1 (signal/noise=3), 0.5560 ?g?mL?1 and 0.1 to 10.0 ?g?mL?1, respectively. The electrochemical sensor was successfully applied for the detection of ametridione in tap, agricultural run-off and river water samples showing >98% mean recoveries.

Equivalent Impedance Models for Electrochemical Nanosensor-Based Integrated System Design

Models of electrochemical sensors play a critical role for electronic engineers in designing electrochemical nanosensor-based integrated systems and are also widely used in analyzing chemical reactions to model the current, electrical potential, and impedance occurring at the surface of an electrode. However, the use of jargon and the different perspectives of scientists and electronic engineers often result in different viewpoints on principles of electrochemical models, which can impede the effective development of sensor technology. This paper is aimed to fill the knowledge gap between electronic engineers and scientists by providing a review and an analysis of electrochemical models. First, a brief review of the electrochemical sensor mechanism from a scientist’s perspective is presented. Then a general model, which reflects a more realistic situation of nanosensors is proposed from an electronic engineer point of view and a comparison between the Randles Model is given with its application in electrochemical impedance spectroscopy and general sensor design. Finally, with the help of the proposed equivalent model, a cohesive explanation of the scan rate of cyclic voltammetry is discussed. The information of this paper can contribute to enriching the knowledge of electrochemical sensor models for scientists and is also able to guide the electronic engineer on designing next-generation sensor layouts.