writer：L. Xiao, J. Sun, L. Liu, R. Hu, H. Lu, C. Cheng, Y. Huang, S. Wang, J. Geng,*
keywords：Graphene, Water-soluble conjugated polymers, Covalent functionalization, Electrostatic attraction, Photothermal killing of bacteria
source：期刊
specific source：ACS Appl. Mater. Interfaces 2017, 9, 5382–5391
Issue time：2017年
Surface modification of graphene is extremely important for applications. Here, we report a grafting-through method for grafting water-solublepolythiophenes onto reduced graphene oxide (RGO) sheets. As a result of tailoring of the side chains of the polythiophenes, the modified RGO sheets, that is, RGO-g-P3TOPA and RGO-g-P3TOPS, are positively and negatively charged, respectively. The grafted water-soluble polythiophenes provide themodified RGO sheets with good dispersibility in water and high photothermal conversion efficiencies (ca. 88%). Notably, the positively charged RGO-g-P3TOPA exhibits unprecedentedly excellent photothermal bactericidal activity, because the electrostatic attractions between RGO-g-P3TOPA and Escherichia coli (E. coli) bind them together, facilitating direct heat conduction through their interfaces: the minimum concentration of RGO-g-P3TOPA that kills 100% of E. coli is 2.5 mu g mL(-1), which is only 1/16th of that required for RGO-g-P3TOPS to exhibit a similar bactericidal activity. The direct heat conduction mechanism is supported by zeta-potential measurements and photothermal heating tests, in which the achieved temperature of theRGO-g-P3TOPA suspension (2.5 mu g mL(-1), 32 degrees C) that kills 100% of E. coli is found to be much lower than the thermoablation threshold ofbacteria. Therefore, this research demonstrates a novel and superior method that combines photothermal heating effect and electrostatic attractions to efficiently kill bacteria.