Wong Elicia L S, Gooding J Justin
School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
Anal Chem. 2006 Apr 1;78(7):2138-44. doi: 10.1021/ac0509096.
The charge-transfer properties of DNA duplexes are exploited to produce a fast, simple, sensitive, and selective DNA biosensor by exposing the DNA recognition interface to a sample containing target DNA and the redox-active intercalator, anthraquinonemonosulfonic acid (AQMS). Electrochemistry from electron transfer through the DNA to AQMS intercalated into DNA duplexes can be differentiated from electrochemistry due to direct access of the AQMS to the electrode surface due to the difference in the environment of the AQMS giving a shift in the potential at which the molecule is reduced. The ability to distinguish between the two electrochemical signals enables DNA hybridization to be monitored in real time. This in situ detection scheme has good selectivity, being able to differentiate between a complementary target DNA sequence and one containing either C-A or G-A single-base mismatches. The concentration detection limit of the biosensor is 0.5 nM (1 pmol) with an assay time of 1 h. The fact that the end user is only required to simultaneously add the sample containing the target DNA and AQMS gives a DNA biosensor that is highly compatible with PCR on chip technologies.
通过将DNA识别界面暴露于含有靶DNA和氧化还原活性嵌入剂蒽醌单磺酸（AQMS）的样品中，利用DNA双链体的电荷转移特性来制备一种快速、简单、灵敏且具有选择性的DNA生物传感器。由于AQMS嵌入DNA双链体时所处环境不同，导致其还原电位发生偏移，使得通过DNA向嵌入DNA双链体的AQMS进行电子转移所产生的电化学信号，能够与因AQMS直接接触电极表面而产生的电化学信号区分开来。区分这两种电化学信号的能力使得能够实时监测DNA杂交。这种原位检测方案具有良好的选择性，能够区分互补的靶DNA序列与含有C - A或G - A单碱基错配的序列。该生物传感器的浓度检测限为0.5 nM（1 pmol），测定时间为1小时。最终用户只需同时添加含有靶DNA和AQMS的样品，这使得该DNA生物传感器与芯片上的PCR技术高度兼容。
