Biomimetic green synthesis of ZnO nanoflowers using α-amylase: from antimicrobial to toxicological evaluation

Biologically mediated synthesis of nanomaterials has emerged as an ecologically benign and biocompatible approach. Our study explores enzymatic synthesis, utilizing α-amylase to synthesize ZnO nanoflowers (ZnO-NFs). X-ray diffraction and energy-dispersive X-ray spectroscopy revealed crystal structure and elemental composition. Dynamic light scattering analysis indicates that ZnO-NFs possess a size of 101 nm. Transmission electron microscopy showed a star-shaped morphology of ZnO-NFs with petal-like structures. ZnO-NFs exhibit potent photocatalytic properties, degrading 90% eosin, 87% methylene blue, and 81% reactive red dyes under UV light, with kinetics fitting the Langmuir–Hinshelwood pseudo-first-order rate law. The impact of pH and interfering substances on dye degradation was explored. ZnO-NFs display efficient bacteriocidal activity against different Gram-positive and negative strains, antibiofilm potential (especially with P. aeruginosa), and hemocompatibility up to 600 ppm, suggesting versatile potential in healthcare and environmental remediation applications.