Fabrication of Sensitive Electrochemical Arsenic (III) Aptasensor

Arsenic (III) contamination in water is a serious worldwide threat for human health. According to the world health organization’s (WHO) report, the maximum permissible contamination ofarsenic in the drinking water is 10 ppb [1]. So early detection of arsenic in low concentration is important. Therefore in this work, a sensitive electrochemical aptasensor was developed for detection of As (III). Various chitosan-nanocomposites were investigated for immobilization ofAs (III) aptamer molecules on the surface of glassy carbon electrode (GCE) [2]. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectroscopy (UV-Vis) were used forcharacterization of fabricated aptasensor. In the present work the effect of various variables such as concentration of glutaraldehyde linker, glutaraldehyde incubation time, capture probeconcentration, capture probe incubation time, aptamer probe concentration, aptamer probe incubation time and nanocomposite composition were investigated. Ander optimum conditions very sensitive As (III) aptasensor was fabricated. Electrochemical impedance spectroscopy wasused to detection of As (III) concentration [3]. The fabricated impidimetric As (III) aptasensor showed very good analytical parameter such as high sensitivity, low detection limit, wide linear range and high selectivity.

Keywords:

Aptasensor , Arsenic (III) , Electrochemical Impedance Spectroscopy , Electrode