Phytochemically modified copper oxide-doped yttrium oxide nanoparticles for antibacterial, photocatalytic and ultralow limit biomarker detection applications

Sustainable production of multifunctional nanomaterials is a key challenge for their widespread use. Phytochemical-assisted synthesis provides an environmentally benign route of nanoparticle modifications towards desired applications. Herein, Catharanthus roseus (CR) leaves extract has been used as a phytochemical modifier for copper oxide-doped yttrium oxide nanoparticles (CuO/Y₂O₃ NPs). The composition, structure, morphology and functional groups of CuO/Y₂O₃ NPs have been extensively modulated via green synthesis. The excellent antibacterial activities against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) pathogens suggest an increasing rate of antibacterial behaviour. Besides, the sheet-like morphology of CuO/Y₂O₃ NPs promotes photocatalytic activities by methylene blue, phenol and methyl orange degradation under sunlight with rates of 0.0203, 0.0152 and 0.0167 min⁻¹. Most importantly, CuO/Y₂O₃ NPs facilitate low oxidation peak potential (−0.58 V), extended frequency linear range (1–300 nM), and ultralow detection limit (up to 0.58 nM) for an important biomarker threonine, which is the best among any nanomaterials reported till date. Such achievement paved the way for sustainable nanomaterial modifications towards multifunctionality.