Printable Conductive Hydrogels for Electrochemical Biosensing and Soft Bioelectronic Interfaces

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Bioelectronics

Background:

• Flexible, conductive biomaterials are crucial for next-generation biosensors and wearable health monitoring.
• Achieving printability, mechanical tunability, biocompatibility, and electronic performance in a single hydrogel is a significant challenge.

Purpose of the Study:

• To present a facile method for fabricating biofunctional conducting poly(ethylene glycol)-poly(pyrrole) (PEG-PPy) hydrogels using 3D-printing.
• To demonstrate the potential of these hydrogels for integration into sensing platforms and electronic interfaces.

Main Methods:

• Fabrication of PEG-PPy hydrogels via 3D-printing using a poly(ethylene glycol) diacrylate matrix and polypyrrole filler.
• Optimization of photopolymerization for extrusion printing of complex structures with high shape fidelity.
• Characterization of mechanical properties (stiffness), cytocompatibility, and electrochemical performance.

Main Results:

• Successfully 3D-printed soft, flexible PEG-PPy hydrogels with tunable stiffness (15-120 kPa) and high printability (≈1).
• Demonstrated high cytocompatibility (>90%) and robust mechanical integrity.
• Achieved electrochemical performance comparable to Ag/AgCl gates in organic electrochemical transistors and enabled enzymatic glucose sensing (1-100 mm).

Conclusions:

• The developed PEG-PPy hydrogel platform is cost-effective, multifunctional, and versatile.
• Offers a scalable route for creating soft, flexible, and printable electronic interfaces for biosensing and wearable devices.