Year: 2026
Type: preprint
Abstract: Cellulose is a natural, abundant and versatile biopolymer that has long been used in traditional applications such as paper and textiles and has gained interest in advanced applications including energy storage, healthcare, food, cosmetics, and coatings. For these applications, achieving robust functionality in cellulose nanocomposites remains a challenge due to poor control over the uniform distribution of added components. Here, we explore enzyme-activated tripeptides as versatile interfacial modifiers for introducing distinct functions into microbial cellulose. First, we demonstrate peptide-mediated formation of melanin-inspired coating with strong light absorption and potential UV-protective properties. Second, we demonstrate incorporation of graphene to create semi-conducting biocomposites. Microbial cellulose was exposed to the tripeptides KYF or KYW in the presence of tyrosinase, promoting peptide oxidation, assembly, and retention within the cellulose network. Pigmented coatings displayed a clear sequence dependence, with KYW exhibiting substantially greater adsorption and uniformity compared to KYF, which is consistent with additional hydrogen-bonding interactions provided by the tryptophan indole side chain and favorable carbohydrate–aromatic interactions that enhance cellulose affinity. In contrast, graphene incorporation was comparable for both peptides, suggesting that graphene immobilization is governed primarily by the general self-assembly of aromatic peptides rather than sequence-specific cellulose binding. The resulting composites showed uniform graphene dispersion, confirmed by optical and electron microscopy and Raman spectroscopy, together with enhanced mechanical performance and electrical conductivity. These findings establish enzymatic peptide oxidation as a versatile strategy for introducing optical and electrical functionality into cellulose-based materials.
Source: ChemRxiv
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223417603