What controls the melting properties of DNA-linked gold nanoparticle assemblies?
What controls the melting properties of DNA-linked gold nanoparticle assemblies?
复制标题
DOI：
10.1021/ja021096v
复制
发表时间：
2003-02-12
影响因子：
15
通讯作者：
Schatz, GC
中科院分区：
文献类型：
--
作者：
Jin, RC;Wu, GS;Schatz, GC
我们报告了一系列实验和理论模型，旨在系统地定义和评估纳米颗粒、寡核苷酸和环境变量的相对重要性，这些变量有助于观察到与dna连接的纳米颗粒结构相关的急剧融化转变。这些变量包括纳米颗粒的大小，纳米颗粒上寡核苷酸的表面密度，周围介质的介电常数，目标浓度，以及纳米颗粒在聚集体中相对于彼此的位置。实验数据可以用热力学模型来理解，该模型将急剧融化归因于两个关键因素的合作机制：每对纳米颗粒之间存在多个DNA连接体，以及由于局部盐浓度的降低而导致DNA链融化时熔化温度的降低。协同熔化效应源于短程双工到双工的相互作用，与所研究的DNA碱基序列无关，对于任何被寡核苷酸大量功能化的纳米结构探针都是普遍存在的。了解DNA连接纳米颗粒聚集体（或单层）熔化特性的基本起源是至关重要的，因为这些特性直接影响人们制定高灵敏度和选择性DNA检测系统的能力，并从这些新型纳米颗粒材料构建材料。
We report a series of experiments and a theoretical model designed to systematically define and evaluate the relative importance of nanoparticle, oligonucleotide, and environmental variables that contribute to the observed sharp melting transitions associated with DNA-linked nanoparticle structures. These variables include the size of the nanoparticles, the surface density of the oligonucleotides on the nanoparticles, the dielectric constant of the surrounding medium, target concentration, and the position of the nanoparticles with respect to one another within the aggregate. The experimental data may be understood in terms of a thermodynamic model that attributes the sharp melting to a cooperative mechanism that results from two key factors: the presence of multiple DNA linkers between each pair of nanoparticles and a decrease in the melting temperature as DNA strands melt due to a concomitant reduction in local salt concentration. The cooperative melting effect, originating from short-range duplex-to-duplex interactions, is independent of DNA base sequences studied and should be universal for any type of nanostructured probe that is heavily functionalized with oligonucleotides. Understanding the fundamental origins of the melting properties of DNA-linked nanoparticle aggregates (or monolayers) is of paramount importance because these properties directly impact one's ability to formulate high sensitivity and selectivity DNA detection systems and construct materials from these novel nanoparticle materials.