Equilibrium gold nanoclusters quenched with biodegradable polymers.
Equilibrium gold nanoclusters quenched with biodegradable polymers.
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DOI：
10.1021/nn303937k
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发表时间：
2013-01-22
期刊：
影响因子：
17.1
通讯作者：
Johnston, Keith P.
中科院分区：
文献类型：
--
作者：
Murthy, Avinash K.;Stover, Robert J.;Borwankar, Ameya U.;Nie, Golay D.;Gourisankar, Sai;Truskett, Thomas M.;Sokolov, Konstantin V.;Johnston, Keith P.
关键词：
尽管亚100 nm的金属纳米颗粒的纳米团簇在包括生物医学成像、传感器和催化剂在内的许多领域中是令人感兴趣的，但是控制它们的形态和化学性质一直具有挑战性。本文提出了一种新的概念，通过调节与聚合物稳定剂PLA（1 k）-b-PEG（10 k）-b-PLA（1 k）的胶体相互作用来组装控制尺寸的平衡Au纳米团簇。纳米团簇形成后混合的分散体的约5 nm的Au纳米球与聚合物溶液，然后通过部分溶剂蒸发。弱吸附的聚合物淬灭平衡纳米团簇尺寸并提供空间稳定性。通过实验改变最终Au纳米颗粒浓度和聚合物/Au比率沿着初始Au纳米颗粒表面上的电荷，将纳米团簇尺寸从~20 nm调谐至~40 nm。在猝灭剂生物降解后，纳米团簇可逆地且完全地解离成单个~5 nm初级颗粒。平衡簇大小半定量预测的自由能模型，平衡短程耗尽和货车德瓦尔斯吸引力与长程静电排斥，作为Au和聚合物浓度的函数。簇中Au纳米颗粒的紧密间距在650至900 nm的宽波长范围内产生强的NIR消光，这在生物医学成像中具有实际意义。
Although sub-100 nm nanoclusters of metal nanoparticles are of interest in many fields including biomedical imaging, sensors and catalysis, it has been challenging to control their morphologies and chemical properties. Herein, a new concept is presented to assemble equilibrium Au nanoclusters of controlled size by tuning the colloidal interactions with a polymeric stabilizer, PLA(1k)-b-PEG(10k)-b-PLA(1k). The nanoclusters form upon mixing a dispersion of ~5 nm Au nanospheres with a polymer solution followed by partial solvent evaporation. A weakly adsorbed polymer quenches the equilibrium nanocluster size and provides steric stabilization. Nanocluster size is tuned from ~20 nm to ~40 nm by experimentally varying the final Au nanoparticle concentration and the polymer/Au ratio, along with the charge on the initial Au nanoparticle surface. Upon biodegradation of the quencher, the nanoclusters reversibly and fully dissociate to individual ~5 nm primary particles. Equilibrium cluster size is predicted semi-quantitatively with a free energy model that balances short-ranged depletion and van der Waals attractions with longer-ranged electrostatic repulsion, as a function of the Au and polymer concentrations. The close spacings of the Au nanoparticles in the clusters produce strong NIR extinction over a broad range of wavelengths from 650 to 900 nm, which is of practical interest in biomedical imaging.
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影响因子：
3.7
作者：
Fresnais, J.;Lavelle, C.;Berret, J. -F.
通讯作者：
Berret, J. -F.
DOI：
10.1073/pnas.2232479100
发表时间：
2003-11-11
影响因子：
11.1
作者：
Hirsch, LR;Stafford, RJ;West, JL
通讯作者：
West, JL
影响因子：
5.5
作者：
Berret, J.-F.
通讯作者：
Berret, J.-F.
影响因子：
8.6
作者：
Kulkarni, AM;Chatterjee, AP;Zukoski, CF
通讯作者：
Zukoski, CF
影响因子：
64.8
作者：
Boal, AK;Ilhan, F;Rotello, VM
通讯作者：
Rotello, VM