Detection of low-molecular-weight pollutants in water using ITO electrochemical sensors

Abstract

One particularly important area in sensor development is the detection of substances with low-molecular -weights such as gases, volatile organic compounds, solvents, pesticides, drugs, biomarkers, toxins, and pollutants[1]. Accurate and efficient detection of these small molecules has attracted considerable attention from the scientific community due to its relevance to diverse fields such as environmental pollutant monitoring, medical diagnosis, food safety, ecosystems, and conservation of aquatic and terrestrial life[1]. Generally, fluorescence, colorimetric, electrochemical, and other methods are used to detect small molecules. Among them, electrochemical sensors were studied as the method most suitable for on-site continuous use. In particular, a sensor using metal oxide nanoparticles was constructed and the detection results were examined in connection with the underwater behavior of low-molecular-weight substances. In this study, ITO film was produced using ITO (Indium Tin Oxide) nanoparticles. We tested several low-weight-molecules like as butanol (D), propanol (D), ethanol (D), trichloroethane (SD), trichlorethylene (SD), acetone (DE), and DI water as analyte. Where, D represents dissolver, SD represents dissolver-sinker and DE represents dissolver-evaporator behavior following the standard European behavior classification. The reaction characteristics of the analytes were obtained using an ITO sensor, and pH changes were also monitored. These results were analyzed based on the behavior of the analytes in water. When the analyte has dissolver characteristics, a linear correlation between pH and sensor response was confirmed. This demonstrates the possibility of determining the type of low molecular weight material through two measurements.