Microfluidic device to investigate factors affecting performance in biosensors designed for transdermal applications

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensor Technology

Background:

• Biosensors are crucial for monitoring biological analytes like glucose and lactate.
• Existing biosensor platforms often face limitations in sensitivity, linear range, and real-time analysis.
• 3D microspike array architectures offer potential for enhanced biosensor performance.

Purpose of the Study:

• To develop and characterize a novel microfluidic platform for investigating 3D out-of-plane microspike array biosensors.
• To evaluate the performance of glucose and lactate biosensors fabricated on this platform.
• To elucidate the factors influencing sensor response, such as enzyme kinetics and membrane permeability.

Main Methods:

• Fabrication of 3D microspike arrays bonded to glass slides.
• Modification of microspikes with glucose oxidase or lactate oxidase via covalent coupling.
• Integration of an epoxy-polyurethane membrane to extend the linear working range.
• Utilizing a microfluidic system for real-time performance evaluation and substrate transfer studies.

Main Results:

• Both glucose and lactate biosensors demonstrated effective performance within the clinically relevant substrate concentration range (0-25 mM).
• Microfluidic analysis indicated that sensor response is primarily governed by enzyme kinetics, not membrane permeability.
• The biosensors exhibited consistent and robust performance for over 48 hours.

Conclusions:

• The novel microfluidic platform enables effective investigation of 3D microspike biosensor performance.
• The developed glucose and lactate biosensors are suitable for clinical applications due to their extended linear range and robustness.
• Understanding the dominance of enzyme kinetics is critical for future biosensor design and optimization.