Plant extract-mediated synthesis and characterization of manganese (II, III) oxide nanoparticles from watermelon (Citrullus lanatus) rinds extract for potential theranostic applications

• Main Authors: Zaragosa, Gelo P., Ilem, Carlo Nonato D.
• Format: text
• Language: English
• Published: Animo Repository 2023
• Subjects: Manganese oxides; Watermelons; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etdb_chem/25; https://animorepository.dlsu.edu.ph/context/etdb_chem/article/1031/viewcontent/2023_Ilem_Zaragosa_Plant_extract_mediated_synthesis_and_characterization_of_manganes_Full_text.pdf
• Institution: De La Salle University

Green synthesis of Mn3O4 nanoparticles for theranostic applications was performed utilizing the plant extract of watermelon (Citrullus lanatus) rinds as a reducing and stabilizing agent. The optical, chemical, structural, and morphological properties of the synthesized Mn3O4 nanoparticles were characterized. UV-Visible absorption of the nanoparticles at 196 nm is associated with the surface plasmon resonance of Mn3O4 nanoparticles. FTIR spectra presented the key chemical functional groups associated with the Mn-O vibrations and phytoconstituents of the C. lanatus rinds extract. XRD analysis revealed the single-phase hausmannite crystalline structure of the Mn3O4 nanoparticles with an average crystallite size of 35.2 nm. SEM and TEM images of the synthesized Mn3O4 nanoparticles showed a morphology of quasi-spherical shapes and a core size of 52.90 ± 8.19 nm and 35.89 ± 0.83 nm respectively. EDS analysis confirmed that the synthesized nanoparticles are mainly composed of Mn, O, and C. The nanoparticles were investigated through DLS and were found to be stable with time and physiological pH conditions. Furthermore, the synthesized Mn3O4 nanoparticles were tested for their antioxidant and relaxivity capabilities as a theranostic agent. The radical scavenging activity through the DPPH assay revealed that the nanoparticles possessed profound antioxidant therapeutic capabilities obtaining an IC50 value of 20.62 ± 0.69 ppm. Relaxivity measurements through NMR revealed the T1 and T2 relaxivity values of the Mn3O4 nanoparticles, which were found to be 5.34 ± 0.11 mM-1s-1 and 63.47 ± 0.60 mM-1s-1 respectively, that demonstrates its capability as a contrast agent for diagnostic imaging. Overall, the results suggest that the green synthesized Mn3O4 nanoparticles have the potential to be a theranostic agent for MRI applications.