Mussel-Inspired Catechol-Functionalized Redox-Active Polypeptides for Energy Applications

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Electrochemistry

Background:

• Developing sustainable and biocompatible electrode materials is crucial for next-generation energy storage.
• Mussel-inspired catechol chemistry offers potential for redox-active, adhesive biopolymers.

Purpose of the Study:

• To synthesize and evaluate catechol-functionalized polypeptides as sustainable, cytocompatible organic electrode materials for energy storage.
• To compare the electrochemical performance of directly synthesized poly(l-DOPA) with dopamine-grafted poly(α-l-glutamic acid).

Main Methods:

• Direct synthesis of catechol-functionalized monomers followed by ring-opening polymerization.
• Characterization using Wide-Angle X-ray Scattering (WAXS), Thermogravimetric Analysis (TGA), and Microscale Combustion Calorimetry (MCC).
• Electrochemical evaluation of thin films and cell-viability assays.

Main Results:

• Direct synthesis yielded poly(l-DOPA) with catechol groups at each repeat unit, exhibiting short-range order and good thermal stability.
• Poly(l-DOPA) demonstrated a quasi-reversible catechol/o-quinone redox process in aqueous solution.
• Composite thin films of poly(l-DOPA) showed significantly higher electrochemical signal intensity than grafted polymers.
• Cell-viability assays confirmed the cytocompatibility of the synthesized polypeptides.

Conclusions:

• Directly synthesized catechol-functionalized polypeptides are promising sustainable and safe organic electrode materials.
• This approach offers improved electrochemical performance and biocompatibility over post-polymerization grafting methods.
• These findings support the use of bio-inspired polypeptides in eco-friendly energy storage applications.