Synthesis and Characterization of Aluminium Oxide Nanoparticles Using Orange Peel Extract for Antibacterial and Antioxidant Activity

The present study employs the aqueous extract derived from orange peel to reduce and encapsulate the green fabrication of aluminium oxide nanoparticles (AlONPs). An investigation into the phytochemicals and functional groups found in orange peel, which play a key role in its bio-reducing properties, is conducted using Gas chromatography/Mass spectrometry (GC-MS), High performance liquid chromatography (HPLC), and Fourier transform infrared spectroscopy (FTIR) analysis. The synthesized AlONPs were characterized using UV-Vis spectroscopy, Field emission electron microscopy (FESEM), and Energy dispersive X-ray) EDX, X-ray Diffraction (XRD), Zeta potential, and FTIR. The FTIR analysis conducted on the orange peel extract demonstrated the existence of functional groups, including hydroxyl, carboxyl, carbonyl, etc., while the Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified the presence of chemical compounds such as (3E)-3,7-dimethylocta-1,3,7-triene, beta-Myrcene, D-Limonene, gamma-Terpinene, and others, exhibiting comparable functional groups. The Ultraviolet-visible (UV-Vis) absorption spectra of AlONPs were acquired at a wavelength of 290 nm. The FESEM analysis demonstrates that the shape of AlONPs is spherical. The antibacterial efficacy of AlONPs synthesized through green methods was assessed against a wide variety of Gram-positive and Gram-negative foodborne pathogens, such as Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella enterica (for antibacterial); Aspergillus niger (for antifungal), using the disk diffusion method. The antiradical scavenging activity using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) was also determined. The highest antibacterial activity can be seen against S. enterica, with a 20 mm zone of inhibition. Additionally, the DPPH free radical scavenging activity of AlONPs was observed to range from 51.62% to 82.29%, indicating a notable capacity to neutralize free radicals and demonstrating significant antioxidant activity. Thus, orange peel fruit extract has significant potential for the production of antioxidant and antibacterial AlONPs suitable for biomedical and pharmaceutical applications.