Green Synthesized Optically Active Organically Capped Silver Nanoparticles using Stem Extract of African Cucumber(Momordica charantia)

Akinsiku, A.A. and Dare, E.O and Ajanaku, K. O. and Adekoya, J. A. and Ayo-Ajayi, J. I. (2018) Green Synthesized Optically Active Organically Capped Silver Nanoparticles using Stem Extract of African Cucumber(Momordica charantia). Journal of Materials and Environmental Sciences, 3. pp. 902-908. ISSN 2028-2508

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Abstract

Silver nanoparticles (Ag NPs) were synthesized by a rapid facile plant-mediated green route. Sustainable and renewable stem extract of locally sourced African cucumber acted as reducing/capping agent, an alternative to toxic chemicals. The phytochemical screening indicated the existence of saponins and alkaloids in the stem extract of M. charantia. Unprecedented nucleation and growth of Ag NPs commenced within 5 minutes of the reaction. The mechanism of reaction was considered to be diffusion controlled Ostwald ripening process. Optical property of the as prepared Ag NPs was characterized by high intensity of absorption, revealed by narrow intense peaks, stipulating confinement of excitons.Surface Plasmon Band (SPB) of Ag NPs appeared at 400 - 460 nm. Photoluminescence (PL)excitation of the Ag NPs at 329 nm exhibited excitonic emission at 440 nm. The Ag NPs portrayed quasi-spherical shapes, with a mean size of 27.81 ± 1.64 nm from Transmission Electron Micrograph (TEM) measurement. XRD measurement showed peaks indexed to fcc Ag with a particle diameter of 25 nm, which corroborated TEM measurement. Elemental mapping of the nanoparticles showed an orientation of the Ag NPs, an evidence of capping by the biomolecules which stabilized the newly formed Ag NPs. Fourier Transformed Infra-red (FTIR) analysis showed the presence of hydroxyl groups (−OH) stretching, (−CH) stretching,C=C stretching and C−N group (in the phytochemicals) at 3237, 2913, 1620 and 1021 cm-1 respectively. It can be inferred that the as prepared Ag NPs is an optically active material.

Item Type:	Article
Uncontrolled Keywords:	Silver nanoparticles; African cucumber; optical property; absorption;emission
Subjects:	Q Science > Q Science (General) Q Science > QD Chemistry
Divisions:	Faculty of Engineering, Science and Mathematics > School of Chemistry
Depositing User:	Mrs Hannah Akinwumi
Date Deposited:	20 Mar 2018 10:17
Last Modified:	20 Mar 2018 10:17
URI:	http://eprints.covenantuniversity.edu.ng/id/eprint/10443

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