Liu Jianyun, Tiefenauer Louis, Tian Shengjun, Nielsen Peter Eigil, Knoll Wolfgang
Max-Planck-Institute for Polymer Research, Ackermannweg 10, D-55128, Mainz, Germany.
Anal Chem. 2006 Jan 15;78(2):470-6. doi: 10.1021/ac051299c.
Using ferrocene-streptavidin conjugates as amplifiers, we recently have demonstrated the simultaneous detection of DNA hybridization to peptide nucleic acid (PNA)-modified gold surfaces at the femtomole level by electrochemical and surface plasmon resonance techniques (Liu, J.; Tian, S.; Tiefenauer, L.; Nielsen, P. E.; Knoll, W. Anal. Chem. 2005, 77, 2756-2761). In this paper, a detailed study of the binding behavior of PNA-DNA is presented by square wave voltammetry and surface plasmon field-enhanced fluorescence spectroscopy (SPFS). The different binding constants for fully matched and single-mismatched DNA were obtained. The effect of the buffer concentration on the PNA-DNA hybrids was investigated using labeled streptavidin by cyclic voltammetry (CV) and SPFS. At high ionic strength, both the CV and SPFS signals were restrained dramatically, which is most probably due to a conformational change of the short-strand PNA-DNA helices on the surface. We conclude that the combination of electrochemical techniques with SPFS is very useful for the study of short DNA structure transformation.
我们最近利用二茂铁 - 链霉亲和素共轭物作为放大器，通过电化学和表面等离子体共振技术，在飞摩尔水平上实现了对与肽核酸（PNA）修饰金表面的DNA杂交的同时检测（刘，J.；田，S.；蒂费瑙尔，L.；尼尔森，P. E.；克诺尔，W.《分析化学》2005年，77卷，2756 - 2761页）。本文通过方波伏安法和表面等离子体场增强荧光光谱法（SPFS）对PNA - DNA的结合行为进行了详细研究。获得了完全匹配和单碱基错配DNA的不同结合常数。使用标记的链霉亲和素，通过循环伏安法（CV）和SPFS研究了缓冲液浓度对PNA - DNA杂交体的影响。在高离子强度下，CV和SPFS信号均显著受到抑制，这很可能是由于表面短链PNA - DNA螺旋结构的构象变化所致。我们得出结论，电化学技术与SPFS的结合对于研究短DNA结构转变非常有用。
