DNA-induced size-selective separation of mixtures of gold nanoparticles
DNA-induced size-selective separation of mixtures of gold nanoparticles
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DOI：
10.1021/ja061651j
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发表时间：
2006-07-12
影响因子：
15
通讯作者：
Mirkin, Chad A.
中科院分区：
文献类型：
--
作者：
Lee, Jae-Seung;Stoeva, Savka I.;Mirkin, Chad A.
我们提出了一种新的方法，利用DNA固有的化学识别特性和DNA功能化的金纳米颗粒的协同结合特性，选择性地分离水介质中的纳米颗粒混合物。我们已经确定了由双链DNA相互连接的纳米颗粒形成的聚集体的熔融温度(T(M)S)与颗粒大小有关。这种效应被认为是由于较大颗粒之间更大的接触面积，从而增加了协同作用，导致更高的T(M)S。分离方案包括从大小不同的颗粒混合物中提取两等分，并用互补DNA对它们进行功能化。对于由较小颗粒形成的聚集体，这些等分在高于T-m的温度下混合，而对于由较大颗粒形成的聚集体，则在T-m以下混合。因此，形成的聚集体几乎完全由较大的颗粒组成，并且可以很容易地通过沉淀和离心法从较小的分散颗粒中分离出来。对于三种颗粒的二元混合物和一种三元混合物，这种不寻常的大小依赖行为和分离协议被演示。
We present a novel method for size-selectively separating mixtures of nanoparticles in aqueous media utilizing the inherent chemical recognition properties of DNA and the cooperative binding properties of DNA-functionalized gold nanoparticles. We have determined that the melting temperatures (T(m)s) of aggregates formed from nanoparticles interconnected by duplex DNA are dependent upon particle size. This effect is proposed to derive from larger contact areas between the larger particles and therefore increased cooperativity, leading to higher T(m)s. The separation protocol involves taking two aliquots of a mixture of particles that vary in size and functionalizing them with complementary DNA. These aliquots are mixed at a temperature above the T-m for aggregates formed from the smaller particles but below the T-m for aggregates formed from the larger particles. Therefore, the aggregates that form consist almost exclusively of the larger particles and can be easily separated by sedimentation and centrifugation from the smaller dispersed particles. This unusual size-dependent behavior and separation protocol are demonstrated for three binary mixtures of particles and one ternary mixture.