Concentration Gradient-Controlled Electrochemical Etching: A Universal Strategy for Nanoelectrodes with Tunable...

Area of Science:

• Bioanalytical Chemistry
• Materials Science
• Nanotechnology

Background:

• High-fidelity intracellular sensing requires minimally invasive nanoelectrodes with controlled tip geometries.
• Conventional etching methods lack reproducibility in modulating tip morphology, especially cone angles.

Purpose of the Study:

• To develop a deterministic fabrication strategy for carbon fiber nanoelectrodes with tailored geometries.
• To enable precise control over nanoelectrode tip angles for enhanced intracellular sensing applications.

Main Methods:

• Concentration gradient-controlled electrochemical etching (CG-CEE) using spatial confinement within a micro-capillary sleeve.
• Modulating sleeve diameter to establish stable axial concentration gradients and control etching kinetics.

Main Results:

• CG-CEE deterministically fabricates carbon fiber nanoelectrodes with controlled tip angles (6°–40°).
• The method demonstrates high reproducibility and versatility, successfully fabricating tungsten needles.
• Achieved precise control over tip morphology for improved cellular sensing.

Conclusions:

• CG-CEE offers a robust and versatile platform for fabricating customized nanotip electrodes.
• This technique enhances intracellular sensing by providing specialized nanoelectrodes.
• The approach is applicable to bioanalytical chemistry and micro-fabrication.