Effect of biosynthesised silver nanoparticles as sterilant on physiological and biochemical characteristics in micropropagation of Musa sapientum L.

Abstract

Green synthesis of silver nanoparticles (AgNPs) using fruit peel extract has gained considerable interest, as it is an eco-friendly and cost-effective method. However, studies on the use of biosynthesised AgNPs to sterilise plant tissue culture medium as an alternative to autoclaving are limited. Thus, this study presented a biogenic method for synthesising AgNPs using mangosteen peel extract. The biosynthesised AgNPs were characterised by different spectroscopic and microscopic methods, including UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive x-ray spectroscopy. The results showed that the phytochemical constituents in the mangosteen peel extract (MPE) helped to reduce Ag+ from AgNO3 to metallic silver (Ag0) and stabilise the particles. The formation of biogenic AgNPs was monitored by UV-vis demonstrating a characteristic peak at 425 nm. The AgNPs were spherical and crystalline. The size distribution of the biogenic AgNPs was 5–47 nm with an average diameter of 23.1 ± 6.8 nm. To evaluate the potential of the AgNPs for use as an alternative method to sterilise the culture medium, the antimicrobial activity of the biosynthesised AgNPs (0.1, 1, 10, 100, and 1000 mg l−1) was tested in the banana culture medium. The most feasible concentration of AgNPs to decontaminate the culture medium was 100 mg l−1. Moreover, the results demonstrated that adding 100 mg l−1 AgNPs to the culture medium promoted the growth of the plantlets without any toxic effects. Thus, biogenic AgNPs are a potential biocide to sterilise in vitro banana culture medium.