Fig. 4

An example of an Escherichia coli comet tail, following treatment with Fe₃O₄-PNIPAAm-3 (a). Results of DNA strand breaks (length of comet tail) for Escherichia coli (b) and Staphylococcus aureus (c) incubated for 30 min with 40% EtOH (positive control), without nanocomposites (negative control), PNIPAAm (0.1 and 1 g/l), and (1) Fe₃O₄-PNIPAAm-1, (2) Fe₃O₄-PNIPAAm-2 and (3) Fe₃O₄-PNIPAAm-3 (error bars represent SD for comet length of 50 cells). Significance level ***P < 0.001