A Research Paper: Synthesis and Characterization of Silver Nanoparticles From Polygonum Minus With Antimicrobial Potential
Purpose: This project propose a study on the development of green silver nanoparticles from plant as an alternative to antibiotics to combat antibiotic resistance bacteria (ARB) or multi drug resistance bacteria (MDRB) in poultry.
Background: Nanotechnology is a rapidly developing and promising field that makes best use of inert metals like silver, gold and platinum to synthesize metallic nanoparticles with high potential for various applications. Among all metal nanoparticles, silver nanoparticles (AgNPs) have much attention due to the surface plasmon resonance (SPR) (strong absorption in the visible region), which can be easily observed by UV–visible spectrophotometer.
Design/Methodology/Approach: Green synthesized of AgNPs have been characterized by Ultraviolet-visible (UV-Vis) spectrophotometer, Field-emission Scanning Electron Microscope (FE-SEM), Transmission Electron Microscopy (TEM), and Energy-Dispersive X-Ray Spectroscopy (EDX)
Results/Findings: The AgNPs formation was observed as a color change of the mixture from yellowish green to reddish brown indicating of reduction of silver ion after several minutes of reaction. The result obtained from UV- Vis spectrophotometer, was showed strong peaks absorbance at 440 nm, which indicating the reduction of Ag+ to metallic Ag. The AgNPs was characterized by Field-emission Scanning Electron Microscope (FE-SEM) and Transmission Electron Microscopy (TEM). The observation of FE-SEM showed the size of AgNPs was produced in range of 15 nm – 25 nm while TEM image shows a well-dispersed silver nanoparticles with roughly spherical shape and size ranging particle size 6 – 21 nm. Three bacteria, i.e. Staphylococcus aureus (ATCC 43300), Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 15442) were chosen to be tested in this study. The morphological changes of bacterial cells treated with AgNPs were observed by FE-SEM, showing that the AgNPs have excellent antimicrobial properties against microorganisms. Thus, the ability of AgNPs to release Ag ions is a critical factor in its antimicrobial activity.
Conclusion and Implications: In this study, the synthesised AgNPs using P. minus extract with aqueous AgNO3 were successfully produced. The synthesised AgNPs were characterised by UV-Vis spectroscopy, FE-SEM, and EDX measurements. The UV-Vis spectra showed a strong peak absorbance at 440 nm that indicated the reduction of Ag+ to metallic Ag. The size of AgNPs produced were in the range of 15–25 nm with strong peaks for silver (Ag) is 82.6% of AgNPs. For the antimicrobial property assessment, Gram-negative bacteria showed more significant inhibition zones compared to Gram-positive bacteria. The morphological changes of bacterial cells treated with AgNPs were observed by FE-SEM and showed that the AgNPs has excellent antimicrobial properties against microorganisms. Thus, it can be concluded that besides being eco-friendly, the application of plant extracts in the synthesis of nanoparticles is also cost-effective, small in size, and effective as an antibacterial agent against various microorganisms, and it holds the potential to be utilised at a larger scale.