End-to-Surface Reaction Dynamics of a Single Surface-Attached DNA or Polypeptide
End-to-Surface Reaction Dynamics of a Single Surface-Attached DNA or Polypeptide
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DOI：
10.1021/jp910669d
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发表时间：
2010-03-11
影响因子：
3.3
通讯作者：
Makarov, Dmitrii E.
中科院分区：
文献类型：
--
作者：
Cheng, Ryan R.;Makarov, Dmitrii E.
表面附着聚合物的动力学在许多生物传感器的操作中起着关键作用，但目前对其的理解相当有限。在这里，我们使用计算机模拟来研究聚合物链的自由端和表面之间的反应动力学，其另一端已连接。我们考虑两个限制的情况下，扩散控制LED限制，其中的反应是完成时，自由链端扩散到指定的距离内从表面，和反应控制的限制，其中缓慢的，内在的反应动力学，而不是扩散的链是速率限制。在扩散控制的极限下，我们发现总速率为N-B，其中N是链中单体的数量，对于排除的体积链，B约为2.2，标度指数B的值接近于从处理链端相对于表面的动力学的简单近似理论中推导出的值，其一维扩散在有效势中。在反应控制极限中，标度指数B的值接近1。我们将我们的研究结果与所有不受约束的聚合物链内的端到端反应的相关（和更好的研究）问题进行比较，并讨论其对电化学DNA传感器的影响。
The dynamics of surface-attached polymers play a key role in the operation of a number of biological sensors, yet its current understanding is rather limited. Here we use computer simulations to study the dynamics of a reaction between the free end of a polymer chain and a surface, to which its other end has been attached. We consider two limiting cases, the diffusion-control led limit, where the reaction is accomplished whenever the free chain end diffuses to within a specified distance from the Surface, and the reaction-controlled limit, where slow, intrinsic reaction kinetics rather than diffusion of the chain is rate limiting. In the diffusion-controlled limit, we find that the overall rate scales as N-b, where N is the number of monomers in the chain and b approximate to 2.2 for excluded Volume chains, This value of the scaling exponent b is close to that derived from a simple approximate theory treating the dynamics of the chain end relative to the Surface its one-dimensional diffusion in an effective potential. In the reaction-control led limit, the value of the scaling exponent b is close to 1. We compare our findings with those for the related (and better Studied) problem of end-to-end reactions within all unconstrained polymer chain and discuss their implications for electrochemical DNA sensors.