Figure 7.

a Decrease of cell index after different concentration ZnO NPs was incubated in the cell system for about 72 h without UV irradiation. b Comparison of cell inhibition for different-sized ZnO NPs in the absence of UV irradiation. c Decrease in cell index after different concentration ZnO NPs was incubated in the cell system for about 72 h with UV irradiation for 180 s. d Comparison of cell inhibition for different-sized ZnO NPs in the presence of UV irradiation for 180 s

Li et al. Nanoscale Research Letters 2010 5:1063-1071   doi:10.1007/s11671-010-9603-4