3-D Printed Adjustable Microelectrode Arrays for Electrochemical Sensing and Biosensing

Area of Science:

• Additive Manufacturing
• Electrochemical Sensors
• Printed Electronics

Background:

• Conventional lithography has limitations for rapid prototyping.
• Printed Electronics offers custom fabrication for sensor applications.
• Microelectrode arrays (MEAs) are crucial for electrochemical sensing.

Purpose of the Study:

• To fabricate silver MEAs using aerosol jet 3D printing.
• To investigate the effect of electrode spacing on sensor performance.
• To establish optimal MEA geometry for electrochemical applications.

Main Methods:

• Fabrication of silver MEAs with varying electrode spacing (30, 100, 180 μm) via aerosol jet printing.
• Electrochemical characterization using hydrogen peroxide and glucose as model analytes.
• Immobilization of glucose oxidase for glucose biosensor development.

Main Results:

• Sensitivity decreased with increased electrode spacing (MEA30:MEA100:MEA180 ratio of 3.7:2.8:1).
• Noise significantly reduced with wider spacing.
• MEA30 electrodes showed diffusion overlap, establishing a lower spacing limit.
• Lowest detection limit for MEAs was 0.45 μM (S/N=3).
• Glucose biosensor sensitivity was 1.73 μAmM⁻¹ with a detection limit of 1.7 μM.

Conclusions:

• Additive manufacturing provides a low-cost method for custom MEA fabrication.
• Optimized MEA geometry is critical for electrochemical sensor performance.
• 3D printed MEAs are viable platforms for diverse sensor applications.