García T, Casero E, Revenga-Parra M, Pariente F, Lorenzo E
Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain.
Anal Chem. 2008 Dec 15;80(24):9443-9. doi: 10.1021/ac801558b.
Selective polynucleotide recognition and detection based on a dual-stage method are described. The method involves the development of a recognition surface based on gold nanoparticles modified with a thiolated capture probe able to hybridize with its complementary sequence (target). After hybridization, this sensing surface is removed from the solution and electrodeposited on an electrode surface. The detection of the hybridization event is achieved using the complex Ru(NH(3))(5)L, were L is [3-(2-phenanthren-9-yl-vinyl)-pyridine], as electrochemical indicator. This complex binds to double strand DNA more efficiently than to single stranded DNA. The advantage of this dual-stage DNA sensing method is the high selectivity derived from the separation of the hybridization event (occurring on one surface) from the detection step (on a different surface), enabling the analysis of long target DNAs, which is usually the case in real DNA sequence analysis. In addition, this approach not only quantifies pmol of a complementary target sequence but also is sensitive to the presence of a single mismatch and its position in the sequence.
描述了基于双阶段方法的选择性多核苷酸识别和检测。该方法包括开发一种基于金纳米颗粒的识别表面,金纳米颗粒用能够与其互补序列(靶标)杂交的硫醇化捕获探针修饰。杂交后,将该传感表面从溶液中取出并电沉积在电极表面。使用配合物Ru(NH(3))(5)L(其中L为[3-(2-菲-9-基-乙烯基)-吡啶])作为电化学指示剂来实现杂交事件的检测。该配合物与双链DNA的结合比与单链DNA更有效。这种双阶段DNA传感方法的优点是,由于杂交事件(发生在一个表面上)与检测步骤(在不同表面上)分离而具有高选择性,从而能够分析长靶标DNA,这在实际DNA序列分析中通常是这样的情况。此外,这种方法不仅可以定量互补靶标序列的皮摩尔数,而且对单个错配的存在及其在序列中的位置敏感。