Nanoscale Inorganic Ion-Exchange Films for Enhanced Electrochemical Heavy Metal Detection

72400-Heavy metal contamination represents a major problem for DOE sites and several private sector operations including mining and metal finishing. This project will develop a compact, portable, low-cost electrochemical monitoring system for heavy metals in water. The system provides a significantly improved sensitivity and detection limit, along with improved reliability and durability of the electrodes, by using a clay mineral modifed surface to enhance signal-to-noise for the analtye. In Phase I, miniaturized monitoring devices on a chip were fabricated and the technical feasibility of the proposed method was proven. Sensitivity and detection limit were improved five-fold (i.e., 500% improvement) compared to a standard anodic stripping electrochemical detection approach. The response of the proposed methods was characterized under a variety of conditions including analyte concentration, pH, and ionic strength. During Phase II, the methods and approaches will be refined and optimized to produce a robust, sensitive system for reliable monitoring of heavy metals. The system will exploit microelectrode technology and an innovative, nanostructured clay mineral preconcentration layer to enable high sensitivity, cost efficient monitoring solutions for toxic heavy metals. Commercial Applications and Other Benefits as described by awardee: The sampling and monitoring system should be applicable to surface and subsurface water contamination problems relevant to DOE needs. In addition, potential private sector applications include monitoring emissions at metal plating facilities, on-site analysis of ground water quality, and on-line and point-of-use monitoring of municipal drinking water.