Hibiscus tiliaceus mediated phytochemical reduction of zinc oxide nanoparticles and emonstration of their antibacterial, anticancer, and dye degradation capabilities

Abstract

The present research focused on the green, non-toxic, low-cost synthesis of zinc oxide nanoparticles (ZnO NPs) using aqueous extract of Hibiscus tiliaceus leaves as a reducing and stabilizing agent. Thus, synthesized ZnO NPs were characterized by nanotechnological applications, i.e., ultraviolet-visible spectroscopy (UV-vis), dynamic light scattering (DLS), zeta potential, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and high-resolution transmission electron microscopy (HR-TEM). The nanotechnological applications showed that as-synthesized ZnO NPs have bandgap energy of 2.97 eV, zeta potential of −1.2 mV, crystalline in nature (JCPDS data card no-89-1397), and an average size of 30 to 60 nm. The FTIR showed that ZnO NPs have coated with plant secondary metabolites and assisted in the process of green synthesis. The ZnO NPs exhibited broad-spectrum antibacterial activity on Gram-positive and Gram-negative bacteria. The ZnO NPs showed potential anticancer activity against human breast cancer cells MCF-7 and determined the IC50 value as 65.83 ± 2.57 µg/mL by MTT assay. Furthermore, ZnO NPs were used as nano-catalyst for dye degradation of methylene blue, methyl orange, and malachite green with NABH4 as a reducing agent. The ZnO NPs exhibited potent dye degradation capability and followed pseudo-first order kinetics. The study concluded that ZnO NPs could be highly useful as anticancer and antibacterial agents in the biomedical field, and as an environmental cleaning agent for dye degradation in textile industries.