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
Department of Chemistry, Texas A&M University, College Station, TX 77843.
Department of Chemical Engineering, Texas A&M University, College Station, TX 77843.
Proc Natl Acad Sci U S A. 2025 Jul;122(26):e2509325122. doi: 10.1073/pnas.2509325122. Epub 2025 Jun 23.
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 B), 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 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 (E) of -1.10 V 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.
受自然启发，我们展示了一种基于多肽的有机氧化还原活性材料，该材料由可再生原料L-谷氨酸（一种氨基酸）和核黄素（维生素B）构建而成，以应对储能系统（ESS）从生命周期开始到结束的管理挑战。氨基酸被用于建立可降解的聚合物主链，沿着该主链引入了许多核黄素分子作为能够实现能量存储的氧化还原活性侧基。整个合成过程包括L-谷氨酸衍生的羧酸酸酐（NCA）单体的开环聚合（ROP），随后用叠氮化物进行侧链活化，最后通过点击偶联实现炔基功能化核黄素部分的安装。核黄素的空间位阻和丰富的化学官能团导致了合成复杂性，需要优化反应以实现所需的聚合物结构。在有机电解质中对所得核黄素多肽进行的电化学表征显示出准可逆的氧化还原活性，半波电位（E）为 -1.10 V 二茂铁/二茂铁鎓（Fc/Fc）。细胞活力测定显示出生物相容性，成纤维细胞的细胞毒性可忽略不计。多肽设计由不稳定的酰胺主链连接和将核黄素单元连接到主链的侧链酯官能团组成，能够实现水解降解以回收用于未来升级循环或回收利用的构建块。这种受生物启发的策略推动了可降解氧化还原活性聚合物的发展，并促进了循环储能技术的可持续材料设计。
