Size-controlled silver nanoparticles synthesized over the range 5-100 nm using the same protocol and their antibacterial efficacy (original) (raw)

Fabrication and characterization of silver nanoparticle and its potential antibacterial activity

Biotechnology and Bioprocess Engineering, 2009

In the present research silver nanoparticle was fabricated by chemical reduction of silver salt (Silver nitrate, AgNO3) solution. Sodium citrate was used as a reducer. The formation of silver nanoparticle was observed visually by color change (greenish yellow). The surface plasmon resonance peak in absorption spectra of silver nanoparticle showed an absorption maximum at 420 nm in UV-VIS spectrometry. The X-ray diffraction pattern showed the presence of sharp reflections at 111, 200, 220, and 311. This would indicate the presence of silver nanoparticle. The scanning electron micrograph revealed that the average size of silver nanoparticle was 21.22 ± 5.17 nm. Silver nanoparticle exhibited better antimicrobial activity against Staphylococcus aureus than the other bacterial pathogens. The correlation coefficient between silver nanoparticles and selected bacterial pathogens revealed that there is a strong negative correlation with Escherichia coli, S. aureus and Klebsiella pneumonia (r = −0.975, −0.993, and −0.998, respectively).

Size-Controlled Facile Synthesis of Silver Nanoparticles by Chemical Reduction Method and Their Antibacterial Performance Against Staphylococcus Aureus and Escherichia Coli

2021

This article describes the size-controlled one-pot facile synthesis of silver nanoparticles (AgNPs) and their antibacterial response against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria. AgNPs coated with and without trisodium citrate (TSC) were synthesized using silver nitrate aqueous precursor and hydrazine as a reducing agent. The appearance of yellowish color with surface plasmon resonance (SPR) with maximum absorbance (λmax) at 416 nm from the ultraviolet-visible (UV–vis) spectrum of the product indicated primarily the formation of the desired product. X-ray diffraction (XRD) pattern confirmed the crystallinity of those products. Field emission scanning microscopy (FESEM) and transmission electron microscopy (TEM) images indicated only spherical AgNPs formation. The existence of a functional group of chemically bonded surface capping agents is confirmed by Fourier transform infrared (FTIR) and the themogravimetric analysis (TGA) weight loss assessme...