High-speed scanning electrochemical microscopy method for substrate kinetic determination: method and theory.

Area of Science:

• Electrochemistry
• Surface Science
• Biophysical Techniques

Background:

• Scanning electrochemical microscopy (SECM) is valuable for analyzing biological samples like living cells.
• Decoupling topographical and reactivity signals in SECM remains a significant challenge.
• Optimizing experimental parameters, such as scan velocity, is crucial for delicate biological samples.

Purpose of the Study:

• To develop a method for extracting substrate kinetic rates from SECM data.
• To address the challenge of separating topographical and reactivity signals.
• To enable kinetic rate determination for samples with unknown surface reactions and complex topographies, including soft biological tissues.

Main Methods:

• Utilizing numerical modeling combined with high-speed constant height SECM imaging.
• Implementing a nonlinear fit strategy for data analysis.
• Adapting the method for slow scan velocities to accommodate delicate samples like cells.

Main Results:

• Successfully extracted substrate kinetic rates using the proposed numerical modeling and SECM approach.
• Demonstrated the ability to decouple topographical and reactivity signals.
• Validated the nonlinear fit strategy for obtaining accurate kinetic rates under slow scan conditions.

Conclusions:

• The developed method provides a robust approach for determining surface reaction kinetics using SECM.
• This technique is particularly advantageous for analyzing biological samples with significant topographical variations.
• The nonlinear fitting strategy enhances the applicability of SECM for studying soft biological samples.