Enhanced Photothermal Bactericidal Activity of the Reduced Graphene Oxide Modified by Cationic Water-Soluble Conjugated Polymer

详细信息    查看全文

• 作者：Linhong Xiao ; Jinhua Sun ; Libing Liu ; Rong Hu ; Huan Lu ; Chungui Cheng ; Yong Huang ; Shu WangJianxin Geng
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2017
• 出版时间：February 15, 2017
• 年：2017
• 卷：9
• 期：6
• 页码：5382-5391
• 全文大小：686K
• ISSN：1944-8252

文摘

Surface modification of graphene is extremely important for applications. Here, we report a grafting-through method for grafting water-soluble polythiophenes 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 the modified 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 μg 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 the RGO-g-P3TOPA suspension (2.5 μg mL^–1, 32 °C) that kills 100% of E. coli is found to be much lower than the thermoablation threshold of bacteria. Therefore, this research demonstrates a novel and superior method that combines photothermal heating effect and electrostatic attractions to efficiently kill bacteria.