To explore the influence of MSNs on the growth of E. coli, cells were incubated in broth with a series of MSNs concentrations (0, 1, 10, 100, 1000 μg/mL). As shown in Fig 2, the OD values of cultures grown in broth with the addition of 1, 10 or 100 μg/mL of MSNs seemed similar to that of the control. However, the growth curves of E. coli became unstable when the concentration of MSNs increased to 1000 μg/mL. Hence, these results indicated that MSNs with a concentration of no more than 100 μg/mL had no remarkable impact on the growth of E. coli. However, when 1000 μg/mL of MSNs was added to the broth, OD values were lower than the other groups and decreased significantly after 4 h, which indicated that a high concentration of MSNs could significantly inhibit the growth of E. coli.