An Electrochemical Sensor for Environmental Detection Based on Reduced Graphene Oxide Modified Electrodes

摘要

The increasing use and associated environmental release of consumed human and veterinary antibiotics have drawn great attention recently. A high percentage of the excreted antibiotics remains in an intact form and enters the natural aquatic systems via the effluent and sludge from wastewater treatment plants, hospitals, and livestock farms. These released antibiotics may lead to bacterial resistance proliferation, contamination or adverse impacts on non-target organisms and microbial ecosystems. Therefore, this situation has created a compelling need to develop sensitive on-site detection techniques for monitoring these antibiotics in the environment. However, delicate instrumentation and complex sample pretreatment requirement of conventional analytical techniques such as spectrophotometry, electrophoresis, and chromatography have hindered their practical applications in real time and in situ sensing task. On the other hand, electrochemical techniques have served as sensitive methods for on-site monitoring with low cost, high efficiency, and minimum sample pretreatment necessity. In the present work, an electrochemical sensor for rapid determination of sulfamethoxazole, one of the most widely used antibiotics, has been developed. Functionalized reduced graphene oxide was used to modify the electrodes owing to its high charge mobility, low background noise, and high surface area. The response was optimized in terms of pH, scan mode, and applied potential. Moreover, the modified electrodes showed great selectivity and stability, and thus collectively, renders it a promising sensor toward detecting sulfamethoxazole in the aquatic system.