Biocompatible Core-Shell Microneedle Sensor Filled with Zwitterionic Polymer Hydrogel for Rapid Continuous...

Area of Science:

• Biomedical Engineering
• Materials Science
• Electrochemistry

Background:

• Microneedle (MN)-based electrochemical biosensors show promise for noninvasive interstitial fluid biomarker monitoring.
• Instability and biofouling are significant challenges hindering the clinical application of MN biosensors.

Purpose of the Study:

• To develop a novel hollow MN biosensor design incorporating a zwitterionic polymer hydrogel sensing layer.
• To address challenges of instability and biofouling in MN biosensors through rational design and micro-nanofabrication.

Main Methods:

• Fabrication of hollow MNs from high-molecular-weight polylactic acid using drawing lithography.
• Encapsulation of a zwitterionic polymer hydrogel sensing layer within the hollow MNs.
• Deposition of a gold nanoconductive layer for stable electrical connection.
• Numerical simulations and experimental validation of sensor performance.

Main Results:

• Successfully fabricated hollow MNs with sufficient strength for epidermal penetration.
• Demonstrated excellent biocompatibility and antifouling properties of the zwitterionic hydrogel.
• Achieved rapid response, high sensitivity, and long-term stability in electrochemical detection.
• Validated accurate and rapid in vivo glucose monitoring capabilities with biosafety.

Conclusions:

• The proposed hollow MN design effectively overcomes limitations of traditional MN biosensors.
• Rational design, structural utilization, and micro-nanofabrication are crucial for advancing MN biosensor technology.
• This innovative approach unlocks the potential of MN biosensors for continuous, noninvasive health monitoring.