Characterization, free radical scavenging and antimicrobial properties of Hibiscus sabdariffa silver Nanoparticle
| dc.contributor.author | Okorondu, Monica Mmachukwu O. | |
| dc.date.accessioned | 2025-04-15T12:13:18Z | |
| dc.date.available | 2025-04-15T12:13:18Z | |
| dc.date.issued | 2025-01 | |
| dc.description | A Doctoral thesis on free radical scavenging and antimicrobial properties. It contains illustrations . | |
| dc.description.abstract | Characterization, free radical scavenging and evaluation of antimicrobial properties of Hibiscus sabdariffa silver nanoparticle were carried out. Nanoparticles were synthesized using biological method and the synthesized nanoparticles were characterized for further confirmation using methods such as UV-Visible Spectroscopy, Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy Dispersive Spectroscopy (EDX) and X-ray diffraction (XRD). Phytochemical screening of the crude and nano extracts of Hibiscus sabdariffa were also carried out using Gas Chromatography Mass Spectroscopy (Gc/Ms) in order to ascertain the biocomponents in the two extracts. Antimicrobial properties of the crude and nano extracts were analyzed using Spectrophotometric assay while the in-vitro free radical scavenging properties of the crude and nano extracts were equally analyzed. The result of the UV-Visible spectroscopy of the nano extract showed maximum light absorption at a wavelength of 420 nm. The EDX revealed 79.52% Ag (silver) and 20.48% O (oxygen). The microscopic studies gave agglomerated spherical silver nanoparticle with average size of 65.9 nm. The XRD result showed that the silver nanoparticle exhibited a polycrystalline face centered cubic (FCC) structure with an average crystallite size of 65.9 nm. The GC/MS result of the crude extract showed a total of fifteen (15) bio-compounds with 4-amino-1,2 naphtoquinone (33.82%) being the highest and hexadecenoic acid, methyl ester (0.36%) being the least in abundance. The GC/MS result of the nano extract showed a total of fifteen (15) organic compounds with Cis-vaccenic acid (46.37%) being the highest and Carbomethoxy vinyl methylamine and 6-octadecanoic acid (0.93%) being the least. The result of the total antioxidant capacity showed a higher antioxidant capacity of the nano extract compared to the crude extract. The crude extract recorded an IC50 of 0.42 mg/ml for DPPH, 0.38 mg/ml for Nitric oxide, 0.33 mg/ml for hydroxyl radical and 0.67 mg/ml for superoxide radical. The nano extract recorded an IC50 of 6.6 mg/ml for 2,2-diphenyl-1- picrylhydrazyl (DPPH), 0.72 mg/ml for nitric oxide radical, 0.28 mg/ml for hydroxyl radical and 0.66 mg/ml for superoxide radical. The antimicrobial properties of the crude and nano extracts showed that the nano extract exhibited improved antimicrobial potency against Escherichia coli (E. coli) and Salmonella typhi compared to the crude extract. The nano extract exhibited enhanced total antioxidant capacity and hydroxyl radical scavenging activity but lower DPPH and nitric oxide radical scavenging activity with improved antimicrobial efficacy against E.coli and Salmonella typhi compared to the crude extract. Both nano and crude extract of Hibiscus sabdariffa could serve as potential antioxidant and antimicrobial agents. | |
| dc.identifier.citation | Okorondu, M. M. O. (2025). Characterization, free radical scavenging and antimicrobial properties of Hibiscus sabdariffa silver Nanoparticle (Unpublished Doctoral Thesis). Fedearl University of Technology, Owerri Nigeria. | |
| dc.identifier.uri | https://repository.futo.edu.ng/handle/20.500.14562/1773 | |
| dc.language.iso | en | |
| dc.publisher | Federal University of Technology, Owerri | |
| dc.rights | Attribution-NonCommercial-NoDerivatives 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | |
| dc.subject | Antioxidant | |
| dc.subject | antimicrobials | |
| dc.subject | free radicals | |
| dc.subject | GC-MS | |
| dc.subject | Hibiscus sabdariffa | |
| dc.subject | silver nanoparticles. | |
| dc.subject | Department of Biochemistry | |
| dc.title | Characterization, free radical scavenging and antimicrobial properties of Hibiscus sabdariffa silver Nanoparticle | |
| dc.type | Doctoral Thesis |