Integration of diffusive gradient thin-film devices and functionalized electrode sensing matrix for discriminative detection of heavy metals in water environments

This study presents a novel approach combining diffusive gradient thin-film devices and a sensing matrix of functionalized electrodes for discrimination and quantification of heavy-metals in water environments. The experimental setup uses four sensing units with interdigitated gold-plated electrodes and an ionic conductive hydrogel. Impedance measurements were conducted using a gain/phase analyzer in the frequency range from 10 MHz to 0.1 Hz. Principal component analysis was applied to enhance data interpretation. The results showed distinct clusters for cobalt (Co²⁺) and manganese (Mn²⁺) ions at concentrations ranging from 10 to 100 ppm, indicating the potential for discrimination between water samples contaminated with these analytes. The integration of IoT and low-cost instruments enables real-time monitoring, wireless transmission of data, and cloud storage. This research contributes to the development of cost-effective methods for heavy metal detection and environmental monitoring, facilitating improved water quality assessment and prompt risk mitigation.