Bacteria-triggered radical anions amplifier of pillar[5]arene/perylene diimide nanosheets with highly selective antibacterial activity

Bacterial infection is one of the most serious physiological conditions threatening human health. There is an increasing demand for selective antibacterial therapy through noninvasive approaches recently years. Herein, a novel strategy for fabrication of positively charged, monolayered nanosheets (P5PD) bearing perylene diimide derivative (DAPDI) was reported through covalent self-assembly with laterally-brominated pillar[5]arene (LBP5). Mannose derivative (Man-HQA) was further immobilized to P5PD nanosheets (named as mP5PD) through host–guest complexation with LBP5 for improving biocompatibility and recognition with microbes. It was found that the mP5PD nanosheets could be converted to radical anions in the presence of E. coli in terms of their excellent reductive surroundings, which showed excellent photothermal conversion efficiency under the 0.5 W/cm2 of 808 nm laser irradiation. Moreover, the selective photothermal antibacterial activity could be realized by the different ability of amplifying radical anions for facultative anaerobic E. coli and aerobic B. subtilis. Importantly, the mP5PD nanosheets exhibited excellent biocompatibility to mammalian cells even at high concentration, which held great potential for developing intelligent photothermal nanomaterials in future biomedical fields.