Fabrication and enzyme-free electrochemical sensing response of polyaniline/silver/clove modified composite electrode

Abstract

The sensitive detection of Hg(II) is a huge consequence for safe environment monitoring and industrial processing. Herein, a sensitive and environment-friendly electrochemical sensor was fabricated using Ag nanoparticles anchored Pani-based bio-nanocomposite. In a simple one-step process AgNPs were prepared using Syzygium aromaticum extract followed by incorporating polyaniline nanostructural array (Pani/Ag/CL) at room temperature through in-situ oxidative polymerization using K2S2O8. The glassy carbon electrode (GCE) was modified with Pani/Ag/CL for the selective electrochemical determination of trace amounts of Hg(II) from different aqueous samples. The electrochemical sensing behavior of the Pani/Ag/CL modified GCE was examined through cyclic voltammetry. The electrochemical impedance analysis of Pani/Ag/CL modified GCE displays favorable kinetic charges for transport. The best reactivity performance for electro-catalytic reduction reactions was observed in a phosphate buffer solution of pH = 5.7. The proposed PANI/Ag/CL modified GCE attains a high sensitivity of 256 μA μM−1 cm−2, a very low limit of detection (0.382 nM), and the limit of quantification (1.27 nM). The practical feasibility and selectivity of the PANI/Ag/CL/GCE were investigated in the sea, tap and wastewater samples with the adequate recovery of Hg(II) added. In addition, the proposed Pani/Ag/CL modified GCE also displayed attractive features such as fast response, simple preparation, repeatability, good stability, as well as detection of the Hg(II) in the occurrence of potential interferences metal cations.