A Peptide-Based Iron Nanozyme with Multienzyme-Mimetic Activity for Sensitive Colorimetric Detection of Glutathione

-coordinated self-assembly into β-sheet-rich nanoribbon architectures, forming a peptide-based metal nanozyme (P6-Fe). Molecular dynamics simulations combined with spectroscopic characterizations confirmed the ordered β-sheet nanoribbon structure and effective metal-ligand coordination. Benefiting from its biomimetic catalytic center and hierarchical assembly, P6-Fe exhibits pronounced multienzyme-mimetic activities, with particularly strong peroxidase-like (POD) performance. Exploiting this catalytic activity, a sensitive and selective colorimetric platform for GSH detection was established, achieving a low detection limit of 1.26 μM. The sensor displays excellent selectivity against common interfering species, along with outstanding catalytic robustness over a wide range of pH values, temperatures, and prolonged storage periods. Furthermore, integration with a smartphone imaging platform enabled rapid and visual quantitative analysis. This work presents a facile, cost-effective, and user-friendly strategy for GSH sensing, while underscoring the considerable potential of peptide-based metal nanozymes for next-generation bioanalytical and diagnostic applications.