Application of microalgal-ZnO-NPs for reusing polyester/cotton blended fabric wastes after modification by cellulases enzymes

Abstract Polyester/cotton (PET/C) blended fabric wastes are produced daily in huge amounts, which constitutes an economic loss and an environmental threat if it is not reused appropriately. Modern textile waste recycling technologies put much effort into developing fabric materials with unique properties, such as bioactivity or new optical goods based on modern technologies, especially nano-biotechnology. In this study, zinc oxide nanoparticles (ZnO-NPs) were biosynthesized using the aqueous extract of Dunaliella sp. and immobilized on PET/C waste fabrics after enzymatically activated with cellulases. The produced Dunaliella -ZnO-NPs (10–20 nm with a spherical shape) were characterized by High-resolution transmission electron microscopy (HRTEM), Fourier-transform infrared spectroscopy (FTIR), X-Ray diffraction analysis (XRD), and Scanning electron microscopy-energy dispersive X-ray analyzer (SEM-EDAX), and some functional groups, such as CH, CO, NH, and CN (due to the presence of carboxyl, proteins and hydroxyl groups), were detected, revealing the biosynthesis of ZnO-NPs. The analysis showed that the resulting ZnO-NPS had potent antimicrobial effects, Ultraviolet (UV) protection capabilities, and no cytotoxic effects on the normal human fibroblast cell line (BJ1). On the other hand, enzymatic treatments of PET/C fabric waste with cellulases enhanced the immobilization of biosynthetic nanoparticles on their surface. Modified PET/C fabrics loaded with Dunaliella -ZnO-NPs showed antibacterial and UV protection capabilities making them an eco-friendly and cost-effective candidate for numerous applications. These applications can include the manufacture of active packaging devices, wastewater treatment units, and many other environmental applications. Graphical abstract