Inhibiting Escherichia coli Growth by Optimized Low-Power Microwave Irradiation—Delivery of Ag and Au Nanoparticles

In a ground-breaking recent study, we unveiled the remarkable cellular uptake of 60 nm ZnO and TiO₂ nanoparticles by NIH/3T3 mouse skin fibroblasts under microwave irradiation. Even more stimulating is our current demonstration of the potent ability of Ag nanoparticles (147 nm) and Au nanoparticles (120 nm) to stifle the growth of <i>Escherichia coli</i> (<i>E. coli</i>-a prokaryote whose cells lack a membrane-bound nucleus and other membrane-bound organelles), vastly smaller than the NIH/3T3 cells, when exposed to significantly optimized low-power microwave irradiation conditions. Our rigorous assessment of the method's effectiveness involved scrutinizing the growth rate of <i>E. coli</i> bacteria under diverse conditions involving silver and gold nanoparticles. This indisputably underscores the potential of microwave-nanoparticle interactions in impeding bacterial proliferation. Furthermore, our noteworthy findings on the uptake of fluorescent organosilica nanoparticles by <i>E. coli</i> cells following brief, repeated microwave irradiation highlight the bacteria's remarkable ability to assimilate extraneous substances.