Electrocatalytic amplification of DNA-modified nanoparticle collisions via enzymatic digestion.
Electrocatalytic amplification of DNA-modified nanoparticle collisions via enzymatic digestion.
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DOI：
10.1039/c6sc02165d
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发表时间：
2016-10-01
期刊：
影响因子：
8.4
通讯作者：
Crooks RM
中科院分区：
文献类型：
--
作者：
Castañeda AD;Robinson DA;Stevenson KJ;Crooks RM
在Exo I消化后电化学检测Np碰撞。我们报告了一个新的和一般的方法，将是有用的适应的方法的电催化放大（ECA）的生物传感应用。在ECA中，催化纳米颗粒与非催化电极表面的单独碰撞导致电流爆发。在这里描述的工作中，电流来自于铂纳米颗粒（PtNPs）表面的N2H4的催化电氧化。迄今为止，将ECA用于生物传感应用的问题在于，必须将受体，例如DNA（如在这里的情况下）或抗体固定在PtNP表面上。然而，这会使碰撞的NP失效，并导致非常小的碰撞签名。在本文章中，我们表明，单链DNA（ssDNA）存在于PtNP表面上可以通过选择性地去除一部分的ssDNA使用酶核酸外切酶I（Exo I）检测。在暴露于Exo I后，与裸PtNP的碰撞相关的电流的约一半可以从完全钝化的PtNP中恢复。使用Au和Hg超微电极进行的实验揭示了用Exo I处理ssDNA修饰的PtNP之前和之后的碰撞过程的一些机理方面。
Np collisions electrochemically detected post-Exo I digestion. We report a new and general approach that will be useful for adapting the method of electrocatalytic amplification (ECA) to biosensing applications. In ECA, individual collisions of catalytic nanoparticles with a noncatalytic electrode surface lead to bursts of current. In the work described here, the current arises from catalytic electrooxidation of N2H4 at the surface of platinum nanoparticles (PtNPs). The problem with using ECA for biosensing applications heretofore, is that it is necessary to immobilize a receptor, such as DNA (as in the case here) or an antibody on the PtNP surface. This inactivates the colliding NP, however, and leads to very small collision signatures. In the present article, we show that single-stranded DNA (ssDNA) present on the PtNP surface can be detected by selectively removing a fraction of the ssDNA using the enzyme Exonuclease I (Exo I). About half of the current associated with collisions of naked PtNPs can be recovered from fully passivated PtNPs after exposure to Exo I. Experiments carried out using both Au and Hg ultramicroelectrodes reveal some mechanistic aspects of the collision process before and after treatment of the ssDNA-modified PtNPs with Exo I.