Enhancement of anti-bacterial potential of green synthesized selenium nanoparticles by starch encapsulation

This study established a cost-effective and environmentally friendly approach to synthesizing the selenium nanoparticles using Artemisia annua (AaSeNPs) and encapsulating the starch (StAaSeNPs) for enhanced anti-bacterial activity. The UV-vis spectra displayed an absorption maxima at 278 nm corresponding to surface plasmon resonance of SeNPs. Particle size were found 70.81 nm for AaSeNPs and 109.2 nm for StAaSeNPs with zeta potential of -26.6 and -30.9 mV respectively. TEM images evidenced that both NPs were spherical in structure with an average particle size of <200 nm. FT-IR indicated the hydroxyl group associated encapsulation of starch in AaSeNPs. The XRD pattern revealed the crystalline nature of SeNPs. The agar well diffusion and micro-dilution assay results revealed that StAaSeNPs had marginally higher bacterial (Staphylococcus aureus, Bacillus cereus, Salmonella enterica, and Escherichia coli) inhibition activity compared to AaSeNPs. Further, these NPs on cellular ultrastructural changes of bacterial pathogens were observed by TEM analysis. These findings indicated that the surface modification of AaSeNPs with starch molecules enhanced the anti-bacterial activity that could be used to treat multidrug-resistant pathogens-related infections.