Nanoscale Inorganic Ion-Exchange Films for Enhanced Electrochemical Heavy Metal Detection
DOE Phase II Contract DE-FG02-03ER83645
This program addresses development of an advanced method for electrochemical monitoring of heavy metals in water. Heavy metal contamination represents a major problem for DOE sites and several private sector operations including mining and metal finishing. The proposed method will provide substantially enhanced performance for electrochemical heavy metal detection sensitivity and detection limit, with mproved reliability and durability of the electrodes.
The overall objective of the combined Phase I and II program will be to develop a compact, portable, low-cost monitoring system for multiple heavy metals which features a significantly improved sensitivity and detection limit by using a clay mineral modifed surface to enhance signal-to-noise for the analtye.
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, ionic strength.
During Phase II the methods and approaches proven feasible in Phase I 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. The Phase II program will include pursuit of several strategies, identified during Phase I, to further improve the ruggedness, response time and sensitivity of the new device.
The proposed sampling and monitoring system will be applicable to surface and subsurface water contamination problems relevant to DOE needs. Examples of 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.