Portable Electrochemical Systems for Heavy Metal Detection in Blood and Water

Considerable evidence exists on the health risks associated with elevated levels of heavy metals. While some heavy metals serve as micronutrients essential for various biological and physiological functions, their toxicity becomes evident when concentrations surpass normal trace levels in the human body. Acute and chronic exposure to elevated levels of heavy metals leads to adverse health effects, including neurological, cardiovascular, and renal diseases, as well as various forms of cancer. Thus, rapid, frequent, and widespread assessment of heavy metal levels in both environmental (e.g., water) and biological (e.g., blood) matrices is crucial for public health. Conventional spectrometry and spectroscopy based analytical techniques are effective in metal quantification but are confined to centralized laboratories due to cost and size of instrumentation, intricate sample preparation requirements, and need for highly trained personnel. The time needed to obtain results using these methods can extend to several months. In contrast, electrochemical techniques have emerged as promising alternatives for sensitive, decentralized monitoring of heavy metals. These techniques offer the advantages of a compact format suitable for point-of-use (POU) applications, relatively low costs, and simplicity of operation. This dissertation describes the development of portable systems for the electrochemical detection of heavy metals in water and blood, potentially deployable for POU applications. Miniature electrochemical sensors were demonstrated for the accurate detection of manganese (Mn) and arsenic (As) in water, and lead (Pb) in blood. The proposed electrochemical systems achieved calculated limits of detection (LOD) of 0.6ppb Mn, 0.6ppb As in water, and 3.9ppb Pb in blood. Validation with ‘real-world’ water and blood samples is presented and benchmarked against spectrometric technique. A human-centered workflow was used to guide the development of a system interface that facilitates the use of the engineered systems by non-expert users.