writer：Rujian Jiang , Lingwan Hao,Lingjie Song , Limei Tian,? , Yong Fan , Jie Zhao,?, Chaozong L
keywords：Synergistic antibacterial Mechanical bactericidal Long-term antimicrobial Biomimetic hierarchical structures Lotus leaf surface
source：期刊
Issue time：2020年

Antibiotics, a power tool to combat pathogenic bacterial infection, have experienced their inability to kill drugresistant bacteria due to the development of antibiotic resistance. As an alternative, nanostructured, mechanical

bactericidal surfaces may hold promise in killing bacteria without triggering antimicrobial resistance; however,

accumulation of dead bacteria would greatly reduce their antimicrobial activity. In this study, for the fifirst time

we report a surprising discovery that the lotus leaf, well known for its superhydrophobicity, has demonstrated

not only strong repelling effffect against bacteria but also bactericidal activity via a cell-rupturing mechanism.

Inspired by this unexpected fifinding, we subsequently designed and prepared a hierarchically structured surface,

which was rendered superhydrophobic (water contact angle: 174°; roll-offff angle: < 1°) upon surface per-

flfluorination. The hierarchically structured surface has displayed remarkable synergistic antimicrobial activity

against Escherichia coli: while the majority of the bacteria (> 99%) were repelled from the surface (non-fouling),

those tenacious bacteria that managed to be in touch of the surface were physically killed completely. Compared

to a conventional superhydrophobic surface (non-fouling to some extent, but no bacteria-killing) or a mechanical

bactericidal surface (bacteria-killing but not bacteria-repelling), our new structured surface has the great advantage in maintaining long-term effffectiveness in antimicrobial activity based entirely on physical mechanism.