A bioinspired and degradable riboflavin- containing polypeptide as a sustainable material for energy storage

• 成果类型: Article
• 署名作者: Li, Shih - Guo; Mohanty, Khirabdhi T.; Easley, Alexandra D.; Rezenom, Yohannes H.; Lim, Soon - Mi; Gillett, Leyla P.; Naquin, Stone D.; Tran, David K.; Nguyen, Tan P.; Lutkenhaus, Jodie L.; Wooley, Karen L.
• 署名单位: Texas A&M University System; Texas A&M University College Station; Texas A&M University System; Texas A&M University College Station; Texas A&M University System; Texas A&M University College Station
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14520
• DOI: 10.1073/pnas.2509325122
• 发表日期: 2025-07-01
• 关键词: redox-active polymers; charge-transport; molecular-weight; ion; mechanisms; batteries; pendants; IMPACT

摘要

Inspired by Nature, we present a polypeptide-based organic redox-active material constructed from renewable feedstocks, L-glutamic acid (an amino acid) and riboflavin (vitamin B2), to address challenges with start-to-end-of-life management in energy storage systems (ESSs). The amino acid was utilized to establish a degradable polymer backbone, along which many copies of riboflavin were incorporated to serve as the redox-active pendant groups that enabled energy storage. The overall synthesis involved the ring-opening polymerization (ROP) of an l-glutamic acid-derived N-carboxyanhydride (NCA) monomer, followed by side chain activation with azides and, finally, click coupling to achieve installation of alkyne-functionalized riboflavin moieties. The steric bulkiness and rich chemical functionality of riboflavin resulted in synthetic complexities that required reaction optimization to achieve the desired polymer structure. Electrochemical characterization of the resultant riboflavin polypeptide, in organic electrolyte, showed quasireversible redox activity with a half-wave potential (E1/2) of ca. -1.10 V vs. ferrocene/ ferrocenium (Fc/Fc+). Cell viability assays revealed biocompatibility, as indicated by negligible cytotoxicity for fibroblast cells. The polypeptide design, consisting of labile amide backbone linkages and side-chain ester functionalities that tethered the riboflavin units to the backbone, enabled hydrolytic degradation to recover building blocks for future upcycling or recycling. This bioinspired strategy advances the development of degradable redox-active polymers and promotes sustainable materials design for circular energy storage technologies.