Ion-imprinted chitosan-stabilized biogenic silver nanoparticles for the electrochemical detection of arsenic (iii) in water samples

Abstract

Arsenic is one of the most harmful heavy metals, and needs constant monitoring and control. A susceptible and selective sensor for arsenic (III) detection in polluted water samples has been developed by using chitosan-stabilized silver nanoparticles (AgNPs). A glassy carbon electrode (GCE) is modified with chitosan-stabilized silver nanoparticles, which provides sufficient sites for interaction with the analyte. The synthesized silver nanoparticles are characterized using different characterization techniques, such as UV-Visible spectroscopy, transmission electron spectroscopy (TEM) and particle size distribution. The particle size and polydispersity index (PDI) value of the chitosan stabilized silver nanoparticles are found to be 6 nm and 0.3, respectively, which enhances the electroactive surface area and hence the sensor sensitivity. The ion imprinting technique is used to improve the selectivity of the sensor. The arsenic sensor is found to be very selective in the presence of other possible interferents like Pb²⁺, Zn²⁺, Cu²⁺, Ag⁺ and Fe²⁺. The detection of As(III) was performed using differential pulse anodic stripping voltammetry (DPASV) and the detection limit was found to be 11.39 pM. The developed sensor is successfully tested for the picomolar level detection of arsenic (III) in different water samples.