Biogenic silver nanoparticles using Rhinacanthus nasutus leaf extract: synthesis, spectral analysis, and antimicrobial studies

This paper has been retracted.

Visweswara Rao Pasupuleti, ¹ TNVKV Prasad, ² Rayees Ahmad Shiekh, ³ Satheesh Krishna Balam, ⁴ Ganapathi Narasimhulu, ⁵ Cirandur Suresh Reddy, ⁴ Ismail Ab Rahman, ³ Siew Hua Gan <sup>1

1</sup>Human Genome Center, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia; ²Institute of Frontier Technology, Regional Agricultural Research Station, Acharya NG Ranga Agricultural University, Tirupati, Andhra Pradesh, India; ³Biomaterial Research Unit, School of Dental Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia; ⁴Department of Chemistry, Sri Venkateswara University, Tirupati, Andhra Pradesh, India; ⁵Pharmacology and Toxicology, Faculty of Pharmacy, University of Technology Mara, Malaysia

Abstract: Nanotechnology is gaining momentum due to its ability to transform metals into nanoparticles. The synthesis, characterization, and applications of biologically synthesized nanomaterials have become an important branch of nanotechnology. Plant extracts are a cost-effective, ecologically friendly, and efficient alternative for the large-scale synthesis of nanoparticles. In this study, silver nanoparticles (AgNps) were synthesized using Rhinacanthus nasutus leaf extract. After exposing the silver ions to the leaf extract, the rapid reduction of silver ions led to the formation of AgNps in solution. The synthesis was confirmed by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. The in vitro antimicrobial activity of the AgNps synthesized using R. nasutus leaf extract was investigated against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli, Aspergillus niger, and Aspergillus flavus using a disc diffusion method. The AgNps showed potential activity against all of the bacterial strains and fungal colonies, indicating that R. nasutus has the potential to be used in the development of value-added products in the biomedical and nanotechnology-based industries.

Keywords: R. nasutus, silver nanoparticles, TEM, antimicrobial activities