Synergy between silk fibroin and ionic liquids for active gas-sensing materials

Area of Science:

• Materials Science
• Biomaterials Engineering
• Bioelectronics

Background:

• Silk fibroin offers excellent biocompatibility and mechanical properties for bioelectronics.
• Challenges include silk fibroin's poor solubility and low intrinsic conductivity.
• Ionic liquids (ILs) can dissolve fibroin, but are typically removed post-processing.

Purpose of the Study:

• To investigate the cooperative potential of ionic liquids and silk fibroin for functional materials.
• To explore the dissolution and gelation of silk fibroin in designer imidazolium chloride-based ionic liquids.
• To assess the suitability of resulting fibroin ionogels for bioelectronic applications, specifically gas sensing.

Main Methods:

• Dissolution of silk fibroin in designer ionic liquids with varying alkyl chain lengths (2-10 carbons).
• Characterization of fibroin secondary structure and gelation properties.
• Fabrication and testing of fibroin ionogels as active components in electronic gas sensors.

Main Results:

• The alkyl chain length of the ionic liquid anion significantly influences fibroin secondary structure.
• Unconventional fibroin arrangements lead to robust gels with hierarchical organization.
• Developed fibroin ionogels exhibit remarkable air-stability and ionic conductivity.

Conclusions:

• Silk fibroin and ionic liquids can be combined to create novel functional materials (ionogels).
• Fibroin ionogels show promise as active materials for air-stable, conductive electronic gas sensors.
• This work highlights untapped potential for silk fibroin in soft and flexible electronics.