Bio-Fabrication of Silver Nanoparticles Using Citrus aurantifolia Fruit Peel Extract (CAFPE) and the Role of Plant Extract in the Synthesis

Tijjani Mustapha; Nur Raihana Ithnin; Hidayatulfathi Othman; Zatul-'Iffah Abu Hasan; Norashiqin Misni

doi:10.3390/plants12081648

Bio-Fabrication of Silver Nanoparticles Using Citrus aurantifolia Fruit Peel Extract (CAFPE) and the Role of Plant Extract in the Synthesis

Plants (Basel). 2023 Apr 14;12(8):1648. doi: 10.3390/plants12081648.

Authors

Tijjani Mustapha^{1

2}, Nur Raihana Ithnin¹, Hidayatulfathi Othman³, Zatul-'Iffah Abu Hasan⁴, Norashiqin Misni¹

Affiliations

¹ Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor Darul Ehsan, Malaysia.
² Department of Biological Sciences, Faculty of Science, Yobe State University, Damaturu P.M.B 1144, Yobe State, Nigeria.
³ Department of Biomedical, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Bandar Baru Bangi, Bangi 43600, Selangor, Malaysia.
⁴ Faculty of Medicine and Health Sciences, Universiti Sains Islam Malaysia, Nilai 71800, Negeri Sembilan, Malaysia.

Abstract

The green synthesis of silver nanoparticles has been proposed as an eco-friendly and cost-effective substitute for chemical and physical methods. The aim of this study was to synthesize and characterize silver nanoparticles using the peel extract of Citrus aurantifolia fruit, and to determine the possible phytochemical constituents' presence in the plant extracts that might be responsible for the synthesis. Citrus aurantifolia fruit peel extraction was followed by phytochemical studies of secondary metabolites, FTIR analysis confirmation of functional groups, and GC-MS analysis. Silver nanoparticles were synthesized through bio-reduction of silver ions (Ag⁺) to silver nanoparticles using CAFPE and characterized using UV-Vis spectroscopy, HR-TEM, FESEM, EDX, XRD, DLS, and FTIR. The presence of plant secondary metabolites such as alkaloids, flavonoids, tannins, saponins, phenols, terpenoids, and steroids was detected. The FTIR analysis of the extract revealed the presence of functional groups like hydroxyl, carboxyl, carbonyl, amine, and phenyl, whereas the GC-MS analysis indicated presence of chemical compounds such as 1,2,4-Benzenetricarboxylic acid, Fumaric acid, nonyl pentadecyl, and 4-Methyl-2-trimethylsilyloxy-acetophenone, etc., with similar functional groups. The synthesized silver nanoparticle (AgNP) has displayed the characteristics of a surface plasmon resonance (SPR) band peak from 360-405 nm. High resolution transmission electron microscope (HR-TEM) and field emission scan electron microscope (FESEM) confirm polydisperse, spherical shaped, and smooth surface nanoparticles with an average size of 24.023 nm. Energy dispersive X-ray (EDX) analysis further revealed that silver is the most abundant element found in the micrograph of the nanoparticles, and FTIR analysis further confirmed the presence of different functional groups in the surface of the nanoparticle. The XRD analysis also confirmed that the nanoparticles synthesized are crystalline in nature. Based on the findings of this study, it is understood that the variety of natural compounds that are present in plant extracts of Citrus aurantifolia fruit peel can act as both reducing and stabilizing agents for the synthesis of silver nanoparticles. It is, therefore, concluded that Citrus aurantifolia peel extract can be potentially used for the large production of silver nanoparticles for several applications.

Keywords: Citrus aurantifolia; green synthesis; metabolites; plant extract; silver nanoparticles.

Grants and funding

This research work was funded by Ministry of Higher Education, Malaysia, through the Fundamental Research Grant Scheme (FRGS): (FRGS/1/2019/STG05/UPM/02/12) and Universiti Putra Malaysia through IPM research grant (GP-IPM/2022/9736100).