Green synthesis of silver nanoparticles using aqueous extract of Citrus sinensis peels and evaluation of their antibacterial efficacy

Abstract

The resistance of microorganisms towards antibiotics remains a big challenge in medicine. Silver nanoparticles (AgNPs) received attention recently for their characteristic nanosized features and their ability to display antimicrobial activities. This work reports the synthesis of AgNPs using the Citrus sinensis peels extract in their aqueous, mild, and less hazardous conditions. The effect of concentration variation (1%, 2%, and 3%) of the plant extracts on the size and shape of the AgNPs was investigated. The antimicrobial activities were tested against gram-positive Staphylococcus aureus and gram-negative Klebsiella pneumoniae. Absorption spectra confirmed the synthesis by the surface Plasmon resonance peaks in the range 400–450 nm for all the AgNPs. FTIR spectra confirmed that Citrus sinensis peels extract acted as both reducing and surface passivating agent for the synthesized AgNPs. TEM revealed spherical AgNPs with average size of 12 nm for 3% concentration as compared to the agglomeration at 1% and 2%. All the AgNPs synthesized using Citrus sinensis peels extracts (1%, 2%, and 3%) exhibited antimicrobial activity against both gram-positive and negative bacteria. These results indicated a simple, fast, and inexpensive synthesis of silver nanoparticles using the Citrus sinensis peels extract that has promising antibacterial activity.

The Effect of Microwave Power in the Green Synthesis of Silver Nanoparticles Using Citrus sinensis Peels Extract

“…Citrus sinensis peel extract contains phenolic, ketone, flavonoid, and terpenoid chemicals commonly observed to have hydroxyl, carbonyl, and carboxyl groups [28]. The phytochemical elements in Citrus sinensis peel extract have been crucial in converting silver ions into silver nanoparticles, as evidenced by the FTIR spectra [29]. Silver nanoparticles are present since their last absorption peaks are located at 460 cm -1 and 473 cm -1 [30,31,32,33].…”