Structural, Optical, And Surface Chemical Analysis Of Piper Longum-Derived Zro2 Nanoparticles And Their Biological Applications

Abstract

Bioengineering of metal oxide nanoparticles has become more popular because of its environmental compatibility and biomedical applications. In this study, the Piper longum catkin extract was used to synthesize the nanoparticles of zirconium oxide (ZrO₂) and their various physicochemical and biological characteristics were studied. X-ray diffraction (XRD) analysis confirmed that highly crystalline and phase-pure zirconia nanoparticles with characteristic diffraction peaks corresponding to the ZrO2 crystalline formation were formed. The field emission scanning electron microscopy indicated that most of the particles were spherical to near spherical and the size of the particles were in the range of 46.35 to 65.66 nm with an average particles size of 56.54 nm. The surface capping and stabilization of the nanoparticles was found to be effective from the presence of Zr–O structural vibrations and phytochemical functional groups obtained from Piper longum by Raman and Fourier transform infrared (FTIR) analysis. Besides, energy dispersive X-ray spectroscopy (EDS) confirmed the elemental purity of the synthesized nanoparticles and only Zr and O were detected with atomic percentages of 29.8% and 70.2% respectively. Biological activities of the synthesized Zr-PL nanoparticles were assessed by antimicrobial, antioxidant and anti-cancer assays. The concentration-dependent antimicrobial activity of the nanoparticles was observed against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Candida albicans with maximum zone of inhibition 3, 3, 4, 5 and 3 mm, respectively at 25 mg mL⁻¹. In the DPPH assay, the free radical scavenging activity gradually increased with increasing concentrations, reaching a maximum inhibition of 43.64% at the concentration of 1000 µg mL⁻¹. In addition, MTT assay showed a dose dependent anticancer activity in A549 (human lung adenocarcinoma) and HeLa (human cervical adenocarcinoma) cell lines with IC₅₀ of 53.18 and 53.93 µg mL-1, respectively. Cell viability was reduced to 39.54 % for A549 cells and 40.62 % for HeLa cells at the concentration of 100 µg mL-1 which shows good growth inhibition. The overall outcome shows that the ZrO₂ nanoparticles prepared by Piper longum have suitable structural behavior and have good antimicrobial, antioxidative, and anticancer properties. The results show that the green-synthesized ZrO₂ nanoparticles are promising candidates for future biomedical and therapeutic applications to be used as multifunctional nanomaterials.