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Potential Dependent Spectroelectrochemistry of Electrofluorogenic Dyes on Indium-Tin Oxide
Vignesh Sundaresan1, Allison R Cutri2, Jarek Metro2
1Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556 USA.
Electrochemical Science Advances
|November 23, 2022
Summary
Indium-tin oxide (ITO) substrates show unexpected luminescence changes with redox probes. High laser power and low probe concentration can reverse expected fluorescence, impacting spectroelectrochemistry.
Area of Science:
- Electrochemistry
- Spectroscopy
- Materials Science
Background:
- Indium-tin oxide (ITO) coated glass is vital for spectroelectrochemistry due to its conductivity and transparency.
- Understanding ITO's spectroscopic properties is crucial for reliable electrochemical studies.
Purpose of the Study:
- To investigate potential-dependent luminescence of electrofluorogenic probes on ITO.
- To identify factors causing anomalous fluorescence behavior under varying conditions.
Main Methods:
- Spectroelectrochemistry using ITO coated glass as a working electrode.
- Studying three probes: flavin mononucleotide, resorufin, and Nile blue.
- Varying laser irradiance and probe concentration.
Main Results:
- Probes showed expected fluorescence quenching upon reduction at low irradiance/high concentration.
- Anomalous fluorescence enhancement occurred at high irradiance/low concentration during reduction.
- Interplay between probe concentration and laser irradiance significantly affected emission.
Conclusions:
- Anomalous luminescence is attributed to irradiance-dependent ITO carrier dynamics and probe-ITO interactions.
- Charge transfer states at reducing potentials alter probe emission.
- ITO behavior can interfere with or reverse observed potential-dependent luminescence, especially under high irradiance/low concentration.
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