The antibacterial activity of Ag@dsDNA@GO composites toward X. perforans, a model plant pathogenic bacterium, is enhanced by the synergistic effect between silver nanoparticles (AgNPs) and graphene oxide (GO).
The researchers observed optimal antibacterial activity with 20 ppm Ag (18 nm)@dsDNA@GO and 16 ppm Ag (5 nm)@dsDNA@GO composites in vitro after an incubation of only 60 min. The Ag@dsDNA@GO displayed higher antibacterial behavior compared to the Ag@GO composite synthesized by different methods, bare AgNPs solution or bare GO solution.
Ag@dsDNA@GO at 100 ppm was applied on tomato transplants in a greenhouse experiment, and significant reduction of disease caused by bacterial spot was visually observed compared to the untreated control and the control treated with copper + mancozeb (the current grower standard treatment).
Application of Ag@dsDNA@GO did not induce any phytotoxic effect on plant leaves. The scientists say that their preliminary results clearly show the great potential in using easily realized nanotechnology for existing severe problems in plants.