DNA aptamer folding on gold nanoparticles: from colloid chemistry to biosensors.
DNA aptamer folding on gold nanoparticles: from colloid chemistry to biosensors.
复制标题
DOI：
10.1021/ja710241b
复制
发表时间：
2008-02
影响因子：
15
通讯作者：
Weian Zhao;William Chiuman;Jeffrey C. F. Lam;Simon A McManus;Wei Chen;Yuguo Cui;R. Pelton;M. Brook-M.-B
中科院分区：
文献类型：
--
作者：
Weian Zhao;William Chiuman;Jeffrey C. F. Lam;Simon A McManus;Wei Chen;Yuguo Cui;R. Pelton;M. Brook-M.-B
我们已经调查了DNA适体的折叠对金纳米粒子（AuNPs）的胶体稳定性的影响，其中适体被拴系。基于对两种不同的适体（腺苷适体和K+适体）的研究，我们发现了与适体折叠相关的独特胶体稳定效应：与未折叠适体结构连接的AuNP相比，折叠适体结构连接的AuNP对盐诱导的聚集更稳定。当在AuNP和适体之间掺入DNA间隔物时，或者当使用较低的适体表面接枝密度时，这种胶体稳定化效果更显著。适体在表面上采用的构象似乎是决定不同AuNP的相对稳定性的关键因素。动态光散射实验表明，在盐溶液中，用折叠适体修饰的金纳米颗粒的尺寸大于用未折叠（但大部分是折叠的）适体修饰的金纳米颗粒的尺寸。从静电和空间稳定的角度来看，从表面延伸更多的折叠适体比未折叠适体对AuNP具有更高的稳定效果。基于这一独特的现象，比色生物传感器已被开发用于检测腺苷、K+、腺苷脱氨酶及其抑制剂。此外，通过添加腺苷和腺苷脱氨酶控制适体折叠和解折叠状态，可以容易地操作不同的AuNP聚集和再分散阶段。
We have investigated the effect of the folding of DNA aptamers on the colloidal stability of gold nanoparticles (AuNPs) to which an aptamer is tethered. On the basis of the studies of two different aptamers (adenosine aptamer and K+ aptamer), we discovered a unique colloidal stabilization effect associated with aptamer folding: AuNPs to which folded aptamer structures are attached are more stable toward salt-induced aggregation than those tethered to unfolded aptamers. This colloidal stabilization effect is more significant when a DNA spacer was incorporated between AuNP and the aptamer or when lower aptamer surface graft densities were used. The conformation that aptamers adopt on the surface appears to be a key factor that determines the relative stability of different AuNPs. Dynamic light scattering experiments revealed that the sizes of AuNPs modified with folded aptamers were larger than those of AuNPs modified with unfolded (but largely collapsed) aptamers in salt solution. From both the electrostatic and steric stabilization points of view, the folded aptamers that are more extended from the surface have a higher stabilization effect on AuNP than the unfolded aptamers. On the basis of this unique phenomenon, colorimetric biosensors have been developed for the detection of adenosine, K+, adenosine deaminase, and its inhibitors. Moreover, distinct AuNP aggregation and redispersion stages can be readily operated by controlling aptamer folding and unfolding states with the addition of adenosine and adenosine deaminase.