Background: In recent times, biosyntheses of metal nanoparticles were used for several life rescue applications. In this study, Dillenia indica leaf aqueous extract was utilized for the synthesis of gold nanoparticles.

Objective: To test anti-microbial properties of biologically fabricated gold nanoparticles.

Methods: Gold nanoparticles were efficiently prepared by making use of aqueous leaf extract of Dillenia indica. The excitation of formed AuNPs was confirmed using UV–Vis spectrophotometer. In particular, absorption spectra of AuNPs exhibited a well-defined SPR band centered at around 530 nm.

Results: The high-resolution Scanning Electron Microscope (SEM) results of the obtained AuNPs confirmed the formation of particles with a size range of 5–50 nm. The ultra-high resolution TEM (UHRTEM) images displayed clear lattice fringes on the particle surfaces. Single crystalline nature of the biosynthesized AuNPs was represented by means of selected-area electron diffraction pattern.

Conclusion: The antibacterial activity of AuNPs revealed significant activity towards both gram negative and gram positive bacteria signifying their potential disinfection related applications in medicine and biology.