New Insights into Electrochemical Detection of Ultra-low Concentrations of Heavy Metals

Description:
Developing metal detection tools in biological systems has become one of the critical research areas in the field of electrochemical sensors owing to the exponential increase in detrimental health-hazardous such as cancers, and kidney and liver diseases caused due to heavy metal exposure. Despite the urgent need, detecting heavy metals in biological samples is challenging for several reasons, such as the complexity of metal chemistry and the limitations of fabrication and analysis protocols of sensors. A tool capable of early detection would be ideal to start early therapeutics, thus preventing further accumulation and minimizing damage to vital body organs. In this vein, we develop novel electrochemical sensors to detect ultra-low concentrations of heavy metals in complicated, aqueous buffers that mimic body fluids or in artificial blood and urine samples. We fabricated a nanoelectrode based on ion transfer across two immiscible electrolyte solutions (ITIES) to detect Cd(II) ions in environmental samples with great sensitivity and excellent stability. We also developed a dual pipet system based on ITIES that can simultaneously detect more than one metal ion. To perform real-time detection of the ultra-low concentration of toxic metals, we engineered a novel, surface-modified carbon-fiber microelectrode (CFM) by electrodepositing dopamine onto the electrode surface. This new surface-modified CFMs significantly improved the limit of detection and sensitivity compared to that of bare CFMs. Moreover, we fabricated a double-bore CFM with two sensing components that can detect two neurotransmitters and heavy metals via fast-scan cyclic voltammetry without altering the detection window of each analyte. To the best of our knowledge, this is the first electrochemical sensor to detect multiple analytes at ultra-fast scan rates. Our preliminary data obtained with these sensors showcases a great possibility of developing these sensors for future in vivo applications.

Speaker: Pavithra Pathirathna - Florida Institute of Technology
Pavithra Pathirathna is an Assistant Professor in the Department of Biomedical and Chemical Engineering and Sciences at the Florida Institute of Technology. She performed her undergraduate studies at the University of Kelaniya, Sri Lanka, and her Ph.D. with Parastoo Hashemi in the Department of Chemistry at Wayne State University, MI. Her postdoctoral work was at the University of Pittsburgh with Shigeru Amemiya. Pavithra’s interdisciplinary and translational research program centers on developing and optimizing electrochemical sensors for analyzing biologically and environmentally impactful metals and neurotransmitters with applications in point of care diagnostics. Some of her prestigious distinctions include Honor Citation for Teaching Service and Esther and Stanley Kirschner General Chemistry Teaching Award. Besides her scholarly and teaching activities, she has been serving as the secretary of the ACS Orlando section since 2021 and a reviewer and a co-editor of several journals.