In Situ Confocal Fluorescence Lifetime Imaging of Nanopore Electrode Arrays with Redox Active Fluorogenic Amplex Red

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Microscopy

Background:

• Understanding spatially heterogeneous electrochemical processes requires direct imaging on electrode surfaces.
• Current imaging techniques may lack the resolution for nanoscale electrochemical interfaces.

Purpose of the Study:

• To develop a strategy for spatially resolved imaging of local faradaic processes on nanoscale electrochemical interfaces.
• To demonstrate the application of this strategy on various electrode dimensions.

Main Methods:

• Utilizing fluorescence lifetime imaging microscopy (FLIM).
• Employing Amplex Red as a fluorogenic redox probe for turn-on imaging.
• Applying the method to microelectrodes and nanopore electrode arrays.

Main Results:

• Verified the capability of Amplex Red for fluorescence lifetime imaging.
• Achieved spatially resolved FLIM-based imaging of faradaic processes.
• Successfully visualized local electrochemical processes on disk-shaped ultramicroelectrodes, interdigitated array microelectrodes, and nanopore electrode arrays.

Conclusions:

• The developed FLIM strategy provides a powerful tool for visualizing nanoscale electrochemical processes.
• This method offers high spatial resolution for studying heterogeneous electrochemistry.
• The technique is applicable to a range of electrode geometries, advancing electrochemical interface analysis.