Indium Tin Oxide Film Characteristics for Cathodic Stripping Voltammetry

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Indium tin oxide (ITO) is valued for conductivity, optical transparency, and a wide anodic potential window, making it suitable for electrochemical measurements.
• Recent applications of ITO include trace metal detection via cathodic stripping voltammetry (CSV), particularly for manganese (Mn).
• Optimization of ITO fabrication and microstructural analysis for CSV remain underexplored, despite CSV's independence from optical transparency and potential for simplified microfabrication on various substrates.

Purpose of the Study:

• To investigate and optimize indium tin oxide (ITO) deposition and processing on silicon (Si) substrates for cathodic stripping voltammetry (CSV) analysis.
• To evaluate the impact of different ITO fabrication parameters, including heated deposition and post-process annealing, on electrochemical performance.
• To establish a baseline for sensitive and selective detection of toxic metals like manganese (Mn) using fabricated ITO electrodes.

Main Methods:

• Fabrication of ITO films on silicon (Si) substrates using various deposition and annealing parameters.
• Characterization of ITO films using surface analysis, bulk analysis (X-ray diffraction), and electrochemical measurements.
• Application of fabricated ITO electrodes for manganese (Mn) detection using cathodic stripping voltammetry (CSV).

Main Results:

• Different ITO fabrication processes exhibited varying electrochemical activities.
• The heated and annealed (HA) ITO fabrication method demonstrated superior performance for Mn CSV.
• A limit of detection (LOD) of 0.1 ppb (1.8 nM) for manganese (Mn) was achieved using the optimized HA ITO electrodes.

Conclusions:

• Optimized ITO fabrication, specifically the heated and annealed (HA) process on silicon substrates, significantly enhances performance for trace metal detection via CSV.
• This work provides a foundation for utilizing ITO as a versatile electrode material for sensitive detection of toxic metals and other contaminants.
• The findings open new avenues for applying ITO in environmental and biological sample analysis using CSV techniques.