Electrochemical Determination of Paraquat Using Gold Nanoparticle Incorporated Multiwalled Carbon Nanotubes

Abstract

The present work focuses on electrochemical estimation of the herbicide, paraquat using Au nanoparticle incorporated multi-walled carbon nanotubes (AuNP-MWCNT). The catalyst was synthesized and characterized using physical characterization techniques like HRSEM, HRTEM, Raman spectroscopy, and XRD. The techniques reveal the successful incorporation of Au nanoparticles onto MWCNT and it was utilized for the electrochemical determination of paraquat (PQ). The AuNP-MWCNT modified glassy carbon electrode (AuNP-MWCNT/GCE) was able to detect PQ reversibly using cyclic voltammetric analysis. From the electrochemical tests, it was discovered that the electrode is an efficient catalyst for the effective electrochemical sensing of PQ. Using the cathodic stripping square wave voltammetric technique (CSSWV), the sensitivity and limit of detection of the matrix against PQ were evaluated. They were found to be 0.197 mA μM−1 and 32 nM, respectively. The electrode is able to produce the linear variation in sensitivity in the concentration range of 1.0 μM to 2.0 μM with a regression coefficient value of 0.99. Further, selectivity studies clearly demonstrated that the proposed catalyst was interference-free from other possible foreign molecules. The practical applicability of the electrode was checked in the electrolyte containing real samples and the appreciable recovery was achieved.