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Indium Tin Oxide for Sensitive Detection of Manganese in Environmentally and Biogically Relevant Samples

MetadataDetails
Publication Date2020-05-01
JournalECS Meeting Abstracts
AuthorsCory A. Rusinek
InstitutionsUniversity of Nevada, Las Vegas

Indium tin oxide (ITO) has long been used as an optically transparent electrode for a variety of applications. For sensing, ITO is commonly seen as the working electrode for spectroelectrochemical measurements where spectroscopic measurements are made under electrochemical control. In this work, however, ITO was investigated for its ability to detect manganese (Mn) in both environmentally and biologically relevant samples using cathodic stripping voltammetry (CSV). ITO exhibited superior performance compared to traditionally-used electrode materials such as glassy carbon, platinum, and boron-doped diamond. The ITO physical vapor deposition (PVD) processes were optimized for Mn detection, including substrate heating during deposition and post-process annealing. Crystallographic changes were observed with the <400> orientation showing the most promise towards Mn detection. Characterization was achieved using multiple topographical and electrochemical methods. Charge-selective polymer films were deposited on the ITO surface to investigate increases in selectivity and/or sensitivity. Using various ITO electrode types, limits of detection (LODs) below 1 ppb were obtained in short measurement times (2-3 min) in environmental samples. In bovine whole-blood samples, ITO exhibited comparable results to those obtained with both graphite furnace- atomic absorption spectroscopy (GF-AAS) and inductively coupled plasma-mass spectrometry (ICP-MS). This work expands on the use of ITO and metal oxides as voltammetric electrodes/sensors; the results presented may be applicable to other analytes amenable to detection by CSV.