Bacteria killing in ICU associated infections: Antibacterial nanosheets as disinfectant

Abstract

Here we report hybrid antibacterial nanosheets (Zn-CuO@GO) where graphene oxide (GO) is decorated with zinc-doped copper dioxide (Zn-CuO) nanoparticles and applied as disinfectant agents to combat multidrug resistant bacterial strains from intensive care units (ICUs). The difference between different Zn-CuO decoration ratios was carefully evaluated and the results indicated when Zn-CuO was deposited onto GO at 4:1 weight ratio (w/w), the obtained Zn-CuO@GO exhibited the best dispersity, which was suitable as an antibacterial supplement for disinfectant. Importantly, the Zn-CuO@GO (4:1, w/w) based disinfectant could actively kill 100.0% multidrug bacteria strains within 10 min, including multidrug resistant (MDR) E. coli and methicillin resistant S. aureus (MRSA). Moreover, we measured the antibacterial activities of Zn-CuO@GO at other decoration ratios (i.e., 21 and 1:1, w/w) to study the effect of Zn-CuO decoration density on the antibiosis activity of Zn-CuO@GO. It was also found that decreased Zn-CuO deposition density not only caused the agglomerateion of Zn-CuO@GO nanosheets (largely due to the relatively increased GO ratio), but also extended their required function time to 30 min for complete bacterial killing. Taking Zn-CuO@GO (4:1, w/w) as the optimized antibacterial nanosheet, further TEM, SEM ad LCSM images revealed that Zn-CuO@GO functions via penetrating and wrapping into the cell wall, inducing bacterial sedimentation and cytoplasma leakage, which make them promising for next-generation disinfectant substitution.