Our experimental observations showed that when E. coli was exposed to MSNs, LDH release increased compared to the control. Fig 4A shows that the LDH release was increased by 8.1%, 13.1%, 16.3% and 17.6% at MSNs concentrations of 1, 10, 100 and 1000 μg/mL, respectively. Tu et al. used computer simulation to model the impairment of cell membranes caused by graphene nanosheets. They demonstrated that both graphene nanosheets and graphene oxide nanosheets could insert into E. coli membranes. This phenomenon explains how graphene nanosheets and graphene oxide nanosheets could generate obvious membrane stress and reduce cell viability of E. coli . The increase of LDH release may be caused by interactions between the MSNs and the surface of the E. coli cell membrane, which in turn might reduce membrane stability and the resistance of E. coli to external substances. MSNs can penetrate cell walls and expose the cell membrane, which decreases its stability. Finally, the amount of LDH apparently increased in this bacterium.