Filter Paper Based Electrochemcial Sensor for Selenium Detection in Water

Abstract

The escalated contamination of water resources with inorganic pollutants is a pressing global problem for the ecosystem due to their well-documented negative effects. Over the years, the problem has aggravated due to uncontrolled industrialization, urbanization and the subsequent disturbance to natural resources by mankind. The direct discharge of inorganic pollutants and their geogenic mobilization has caused their elevated concentrations in ground, surface and river water. Selenium is amongst the emerging inorganic pollutants of concern besides other and was neglected earlier by the environmentalist due to their occupancy in other major pollutants and lack of sensitive analytical techniques. It is essentially known as a beneficial element, however, when consumed above a permissible limit, it may lead to devastating acute and chronic health effects. With the advancement made in paper analytical devices, we herein present for the first time the in-situ prepared flexible electrodes from “lab grade filter paper” for selenium sensing in water with high selectivity and sensitivity. The paper electrode are modified with nanostructured materials (metallic nanoparticles) to introduce conductivity, and thereafter utilized as a transduction platform in anodic stripping voltametric based detection of selenium. The flexible paper electrodes are also studied for their structural, compositional and electrochemical characteristic. A battery of ions are tested under competitive and comparative performance evaluation of fabricated sensor electrodes to realize their practical applications in real water samples. The analytical performance of the paper sensor is also validated against ion chromatography reference technique. The designed sensor electrode demonstrate a wide detection capability of 5-1000 ppb, high sensitivity, and excellent detection limit <10 ppb.