Bio-inspired facile synthesis of CeO2-TiO2 nanocomposites using calyx leaves extract of Physalis peruviana fruits and their biological assessments: Antibacterial and antioxidant activity

Green synthesis has emerged as a transformative approach in nanotechnology, driven by its environmentally friendly, safe, and sustainable principles. In this study, we present a bio-inspired method for the synthesis of CeO₂-TiO₂ nanocomposites (NCs) using phytochemicals extracted from the outer calyx leaves of Physalis peruviana fruits, under ultrasound sonication. This eco-friendly technique not only eliminates the need for hazardous chemicals but also capitalizes on the natural reducing and capping properties of biowaste. The synthesized NCs were thoroughly characterized using fourier-transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Their antibacterial activity was evaluated against various Gram-positive and Gram-negative bacteria, and their antioxidant potential was also assessed. This work highlights the remarkable role of phytochemicals from fruit calyx leaves as bio-templates, facilitating the sustainable production of CeO₂-TiO₂ NCs. The ultrasound-assisted synthesis provides a rapid, energy-efficient, and scalable process for nanocomposite fabrication, demonstrating excellent biocompatibility, uniformity, and stability. Furthermore, the approach not only offers a solution to the challenge of hazardous chemical use in nanoparticle (NPs) synthesis but also contributes to waste management by valorizing agricultural by-products. Our findings underscore the promising applications of green-synthesized CeO₂-TiO₂ NCs in the biomedical and pharmaceutical industries, paving the way for future advancements in eco-friendly nanotechnology.