Carbon Dot-Coated Bambusa vulgaris Fibers: Structural, Photoluminescent, and Antibacterial Properties for Sustainable Functional Applications

Cellulose-rich natural fibers provide a renewable platform for developing sustainable functional materials. This study investigated carbon dot-coated Bambusa vulgaris fibers prepared through a simple dip-assisted coating approach to introduce optical and antibacterial functionalities. X-ray diffraction revealed a semi-crystalline structure with a crystallinity index of 16.9%, while FTIR analysis identified oxygen-containing functional groups consistent with possible non-covalent interactions between CDs and the cellulose surface. The coated fibers exhibited a tensile strength of 196.95 ± 2.82 MPa, strain at break of 0.062 ± 0.004, and Young’s modulus of 4.13 GPa. Photoluminescence analysis showed broad visible emission from 410–710 nm, with maximum intensity of 4892 a.u. at 548 nm. CLSM qualitatively confirmed fluorescence distributed along the coated fiber surface. Antibacterial testing at 100 μg mL⁻¹ produced inhibition zones of 15 mm against Escherichia coli and 14 mm against Staphylococcus aureus , corresponding to 78.9% and 82.4% of the activity of the 10 μg streptomycin control, respectively. These findings demonstrate successful optical surface modification and antibacterial activity of carbon dot-coated Bambusa vulgaris fibers for sustainable functional material applications. The limitations of this study is the absence of quantitative CD loading and coating-stability measurements, direct antibacterial mechanistic assays, and cytotoxicity and biocompatibility evaluations, which currently limits confirmation of long-term biomedical applicability.