Microelectrode Arrays in Thin-Layer Cells for Rapid, Sensitive, and Calibration-Less Determination of Arsenic in Μl Volumes by Anodic Stripping Coulometry

Abstract

Recent contamination events have emphasized the need for widespread heavy metal monitoring over extended periods of time. The customary and laborious random "grab sampling" for later analysis at central laboratories does not adequately satisfy this need. Our group is developing an electroanalytical approach that allows highly sensitive, calibration-less measurements to quantify heavy metals in microliter volumes. This approach offers promise for economical, miniaturized, remotely-deployable sensor networks. This study reports the application of microfabricated gold microelectrode arrays within a thin-layer cell and demonstrates sufficient sensitivity to detect sub-5-ppb arsenic concentrations in a microfluidic sample volume (< 5 µL).

An electrochemical instrument for the analysis of heavy metals in water via anodic stripping coulometry for applications in remote sensing.

“…Preliminary results of As(III) concentration versus intercept-corrected charge (IcC) for a 5 µm array (red), 20 µm array (green), 50 µm array (blue), and macroelectrode (black)[79]. Predicted results of As(III) concentration versus charge for a 5 µm array (red), 20 µm array (green), 50 µm array (blue), and macroelectrode (black).…”