Sustainable PVA/gelatin nanofibers reinforced with tomato-peel-derived carbon quantum dots for enhanced optical and mechanical properties

Abstract

Increased interest in sustainable and biodegradable materials has driven advances in nanotechnology. This study explores the fabrication of nanofibers using polyvinyl alcohol (PVA) integrated with carbon quantum dots (CQDs) obtained from tomato peel waste and gelatin to produce hybrid materials with improved optical and mechanical properties. Unlike conventional CQD–polymer systems, the present work examines a hybrid PVA/gelatin matrix reinforced with biomass-derived CQDs and evaluates the resulting structure property correlations. Structural and morphological analysis indicates that the addition of CQDs enhances nanofiber characteristics, including increased crystallinity and reduced fiber diameter. Optically, one variant of PVA/CQDs/gelatin nanofibers exhibits superior fluorescence at a wavelength of 380 nm. Meanwhile, thermal analysis via TGA/DTA revealed that the greatest mass loss occurred between 250 – 500 °C, indicating superior thermal stability. Mechanical properties also improved, with increased tensile strength due to the synergistic interaction between PVA, CQDs, and gelatin, which can enhance the strength and flexibility of the fibers. Additionally, antibacterial testing revealed that the fabricated PVA/CQDs/gelatin nanofibers exhibit stronger inhibition against Escherichia coli (Gram-negative) compared to Staphylococcus aureus (Gram-positive. Antibacterial evaluation in this study was conducted as a preliminary qualitative screening to confirm the intrinsic antimicrobial activity of the nanofibers, rather than as a quantitative comparison with standard antibiotics. These findings highlight the multifunctional potential of PVA/CQDs/gelatin nanofibers for advanced material applications, particularly as a proof-of-concept toward sustainable active packaging materials. Future research will optimize fabrication techniques, scalability, and include quantitative antimicrobial benchmarking against standard antibiotics and minimum inhibitory concentration (MIC) analysis for broader functional applications.