Qian Ximei, Li Jun, Nie Shuming
Department of Biomedical Engineering, Emory University, 101 Woodruff Circle Suite 2001, Atlanta, Georgia 30322, USA.
J Am Chem Soc. 2009 Jun 10;131(22):7540-1. doi: 10.1021/ja902226z.
Stimuli-responsive surface-enhanced Raman scattering (SERS) nanoparticles have been developed by using colloidal gold nanocrystals and a class of thiolated block copolymers consisting of a pH-responsive polymer segment, an amphiphilic polyethylene glycol segment, and a lipoic acid anchoring group. The results demonstrate that SERS signals can be switched on and off by molecular conformations in response to pH. An important finding is that neutralized polymethacrylic acid (PMAA) molecules are able to interact with amphiphilic polyethylene glycol (PEG) chains, leading to highly compact and intermingled copolymer structures on the surface of nanoparticles. This type of molecular conformation change provides a new strategy for controlling plasmonic coupling and electromagnetic Raman enhancement and raises the possibility of using SERS nanoparticle tags for biomolecular binding and enzymatic cleavage studies.
通过使用胶体金纳米晶体和一类由pH响应性聚合物链段、两亲性聚乙二醇链段和硫辛酸锚定基团组成的硫醇化嵌段共聚物，开发了刺激响应性表面增强拉曼散射（SERS）纳米颗粒。结果表明，SERS信号可以通过响应pH的分子构象来开启和关闭。一个重要的发现是，中和的聚甲基丙烯酸（PMAA）分子能够与两亲性聚乙二醇（PEG）链相互作用，导致纳米颗粒表面形成高度致密且相互交织的共聚物结构。这种分子构象变化为控制等离子体耦合和电磁拉曼增强提供了一种新策略，并提高了使用SERS纳米颗粒标签进行生物分子结合和酶促裂解研究的可能性。
