A green synthesis strategy of silver nanoparticles using aqueous extract of waste banana pseudo-stem and its anti-MRSA activity

Abstract

A green organic approach was employed to employ discarded banana plant stems as both a reducing agent and a capping agent for synthesising silver nanoparticles, followed by analytical characterization. The synthesised nanoparticles were analysed by UV-visible spectroscopy, FT-IR, XRD, and TEM. Preliminary UV-visible analysis warranted the presence of silver nanoparticles, with maximum absorption reported at 428 nm. The transmission electron microscopy (TEM) study showed the presence of spherical nanoparticles that were black in colour with an average size of 200 nm. The FT-IR test also revealed that some secondary compounds have functional groups that, through bio-reduction, change silver nitrate into metallic nanosilver. The growth kinetics, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of Methicillin-Resistant Staphylococcus aureus (MRSA), a gramme-positive bacteria, were assessed to identify the impact of AgNPs on MRSA. The maximum zone of inhibition identified for MRSA was 15±2 mm. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and MBC/MIC ratio of silver nanoparticles against methicillin-resistant Staphylococcus aureus (MRSA) were found to be 81 mg/mL, 162 mg/mL, and 2.0, respectively.