Highly Efficient Functionalized Chitosan in the Development of Electrochemical Sensor for Trace Detection of Pb (II)

Abstract

Fabrication of a working electrode with silane grafted chitosan (CHTMS) employed in the sensitive detection of Pb(II) in aqueous media is presented. Several advanced analytical methods have extensively characterized the nanocomposite material. The prepared material was subsequently employed for modification of a glassy carbon electrode (GCE) and characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), which show a 3-fold enhancement in surface area compared with the bare GCE, and a charge transfer resistance of 678.7 Ω. The modified electrode was employed in the sensitive determination of Pb(II) in aqueous media using differential pulse anodic stripping voltammetry (DPASV), where optimization of experimental parameters such as pH, deposition time and deposition potential was carried out. Under optimized conditions, the linear regression and correlation coefficient were obtained, which show that Pb(II) can be detected over a wide concentration range with a calculated limit of detection (LOD) of 2.83 μg l−1, which is lower than the permissible limit set by the WHO. For practical applicability, reproducibility and stability tests as well as real water sample analyses were further performed, with the obtained recovery rates showing promising results.