A Fast and Efficient Replacement of CTAB with MUA on the Surface of Gold Nanorods Assisted by a Water‐Immiscible Ionic Liquid |
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| Authors: | Linjia Su Song Hu Li Zhang Zhuoran Wang Weiping Gao Jing Yuan Minghua Liu |
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| Affiliation: | 1. Department of Chemistry, Capital Normal University, Beijing, P. R. China;2. Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid, Interface, Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, P. R. China;3. Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, P. R. China |
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| Abstract: | The synthesis and surface modification of gold nanorods (GNRs) is one of the most important and basic issues in nanoscience. Most of the widely investigated GNRs are coated with a cetyltrimethylammonium bromide(CTAB) bilayer. Here, a highly efficient method is proposed to replace CTAB from the surface of GNRs with a bifunctional 11‐mercaptoundecanoic acid in order to decrease the possible toxicity caused by CTAB. This ligand exchange is achieved in a biphasic mixture of an aqueous solution and a water‐immiscible ionic liquid (IL), BMIM]Tf2N]. That is, by mixing IL, mercaptoundecanoic acid (MUA)/IL (200 × 10?3 m ) and a concentrated aqueous solution of GNRs together, followed by vortex stirring for 90 s, CTAB‐capped GNRs with varying aspect ratios can be turned into corresponding MUA‐capped GNRs with the same aspect ratio. Furthermore, the formed MUA‐capped GNRs can be obtained in a large quantity and stored as powders for easy use. The MUA‐capped GNRs with improved biocompatibility and colloidal stability are well suited for further biological functionalization and potential applications. This IL‐assisted ligand exchange can reverse the surface charge, enhance the stability of GNRs, and suppress its cytotoxicity. |
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| Keywords: | cytotoxicity gold nanorods ionic liquid ligand exchange surface coating |
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