Research Seminar Abstract

Heavy metal pollution is ubiquitous throughout the environment, often a result of anthropogenic sources, and chronic or acute exposures have significant negative impacts on human and environmental health. Current, centralized laboratory testing is often insufficient for large-scale environmental testing and limiting exposures as a result of high costs ($100s per sample) and extensive training required. New inexpensive and rapid alternatives are needed for testing at the point-of-need. The simultaneous detection of multiple metals from a single sample is a beneficial tool to further reduce cost and analysis time; however, this is challenging in the field with current electroanalytical techniques, where tuning assay conditions for a metal often results in poor selectivity and/or sensitivity for other metals in the mixture, if not outright requiring a separate assay. Stencil printed carbon electrodes (SPCEs) are the typical electrode choice for point-of-need diagnostics, owing to their disposability and low cost. SPCEs suffer from relatively poor electrochemical characteristics though, requiring extensive, time-consuming, and expensive electrode surface modifications to detect metals. In this work, an electrochemical paper-based analytical device (ePAD) for simultaneous electrochemical detection in dual operating conditions whereby sample is wicked down separate channels containing specific reagents for the optimal detection of each metal is discussed. A novel glassy carbon microparticle stencil printed electrode (GC-SPE) composition, which outperforms conventional SPCEs for the detection of Cd and Pb, is also developed with the goal of combining the ePAD and SPCEs toward simpler devices for the detection of heavy metals at the point-of-need. The GC-SPEs have been used to detect trace Cd and Pb, without prior modification, providing detection limits of 2.5 and 5.0 ppb respectively. The ePAD and electrodes developed in this work significantly simplify heavy metal analysis in the field, providing a more rapid response to exposure without adding to the cost.