Department of Chemistry, Brown University, Providence, RI 02912, United States.
J Colloid Interface Sci. 2012 Dec 1;387(1):221-7. doi: 10.1016/j.jcis.2012.07.058. Epub 2012 Aug 10.
Anthracene Diels Alder adducts (DAa) bearing two long side chains (H-(CH(2))(22)O(CH(2))(6)OCH(2)-) at the 1- and 5-positions form self-assembled monolayers (SAMs) at the phenyloctane-highly oriented pyrolytic graphite (HOPG) interface. The long DAa side chains promote strong physisorption of the monolayer to HOPG and maintain the monolayer morphology upon rinsing or incubation in ethanol and air-drying of the substrate. Incorporating a carboxylic acid group on the DAa core enables capture of 1-4 nm diameter gold nanoparticles (AuNPs) provided (i) the monolayer containing DAa-carboxylic acids is treated with Cu(2+) ions and (ii) the organic coating on the AuNP contains carboxylic acids (11-mercaptoundecanoic acid, MUA-AuNP). AuNP capture by the monolayer proceeds with formation of Cu(2+)-carboxylate coordination complexes. The captured AuNP appear as mono- and multi-layered clusters at high coverage on HOPG. The surface density of the captured AuNPs can be adjusted from AuNP multi-layers to isolated AuNPs by varying incubation times, MUA-AuNP concentration, the number density of carboxylic acids in the monolayer, the number of MUA per AuNP, and post-incubation treatments.
蒽 Diels-Alder 加合物（DAa）在 1 位和 5 位带有两条长侧链（H-(CH(2))(22)O(CH(2))(6)OCH(2)-），在苯辛烷-高取向热解石墨（HOPG）界面形成自组装单层（SAMs）。长的 DAa 侧链促进了单层对 HOPG 的强物理吸附，并在冲洗或在乙醇中孵育以及在基底干燥时保持单层形态。在 DAa 核心上引入羧酸基团可捕获 1-4nm 直径的金纳米粒子（AuNPs），前提是（i）含有 DAa-羧酸的单层用 Cu(2+) 离子处理，（ii）AuNP 上的有机涂层含有羧酸（十一巯基十一烷酸，MUA-AuNP）。AuNP 的捕获通过形成 Cu(2+)-羧酸配位复合物进行。在 HOPG 上，捕获的 AuNP 在高覆盖率下呈现单和多层团簇。通过改变孵育时间、MUA-AuNP 浓度、单层中羧酸的数量密度、每个 AuNP 上的 MUA 数量以及孵育后的处理，可以调节捕获的 AuNP 的表面密度，从 AuNP 多层到孤立的 AuNP。
