Mangifera indica L. stem bark used in the bioinspired formation of silver nanoparticles: catalytic and antibacterial applications

This study reports the use of aqueous mango stem bark extract (MSBE) as a source of a relatively cheap and easily accessible reducing and stabilizing agent for the biosynthesis of silver nanoparticles (AgNPs). The biosynthesis was conducted at 80 degrees C and pH 9 within 30 min. The FTIR and UV-Vis spectroscopic characterization of the MSBE provided evidence of chromophoric phytoconstituents with reducing functional groups. These constituents served as reducing and stabilizing agents as they were observed in the FTIR spectrum of the AgNPs. Similarly, the SEM micrograph and TGA thermogram indicated the presence of MSBE phytoconstituents on the surface of the synthesized AgNPs. The HRTEM revealed the polycrystalline nature of the AgNPs which adopted quasi-spherical and elliptical morphologies with sizes in the range 5-50 nm. The AgNPs showed remarkable catalytic activity in the degradation of methylene blue dye with a pseudo-first-order rate constant of 0.0089 s(-1). The degradation was completed within 280 s. In addition, the AgNPs displayed improved antibacterial activity in comparison with the MSBE against clinical pathogens. Based on the findings in this study, AgNPs can serve as a potential catalyst in water treatment and also as an antimicrobial agent in disinfectant formulations.

Automated summary

This study demonstrates the use of aqueous mango stem bark extract as a reducing and stabilizing agent for the biosynthesis of silver nanoparticles. The nanoparticles exhibit catalytic activity and enhanced antibacterial properties.