Heaton R J, Peterson A W, Georgiadis R M
Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA.
Proc Natl Acad Sci U S A. 2001 Mar 27;98(7):3701-4. doi: 10.1073/pnas.071623998. Epub 2001 Mar 20.
We demonstrate that in situ optical surface plasmon resonance spectroscopy can be used to monitor hybridization kinetics for unlabeled DNA in tethered monolayer nucleic acid films on gold in the presence of an applied electrostatic field. The dc field can enhance or retard hybridization and can also denature surface-immobilized DNA duplexes. Discrimination between matched and mismatched hybrids is achieved by simple adjustment of the electrode potential. Although the electric field at the interface is extremely large, the tethered single-stranded DNA thiol probes remain bound and can be reused for subsequent hybridization reactions without loss of efficiency. Only capacitive charging currents are drawn; redox reactions are avoided by maintaining the gold electrode potential within the ideally polarizable region. Because of potential-induced changes in the shape of the surface plasmon resonance curve, we account for the full curve rather than simply the shift in the resonance minimum.
我们证明，在施加静电场的情况下，原位光学表面等离子体共振光谱可用于监测金表面束缚单层核酸膜中未标记DNA的杂交动力学。直流电场可增强或延缓杂交，还能使表面固定的DNA双链变性。通过简单调节电极电位即可实现对匹配和错配杂交体的区分。尽管界面处的电场极大，但束缚的单链DNA硫醇探针仍保持结合状态，可重复用于后续杂交反应而不损失效率。仅产生电容性充电电流；通过将金电极电位维持在理想极化区域内避免了氧化还原反应。由于表面等离子体共振曲线形状的电位诱导变化，我们考虑的是完整曲线而非仅仅是共振最小值的偏移。
