Yang Xiaohai, Wang Qing, Wang Kemin, Tan Weihong, Yao Jing, Li Huimin
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Bio-Nano Technology Engineering Research Center of Hunan Province, Changsha, People's Republic of China.
Langmuir. 2006 Jun 20;22(13):5654-9. doi: 10.1021/la052907m.
The switching of DNA monolayers between a "lying" and a "standing" state initiated by applying electric field, and the subsequent DNA hybridization at different states were investigated in a contactless, label-free mode by surface plasmon resonance (SPR) technique. The results showed that the strength of the electric field and surface coverage could influence the switching of DNA monolayers. In addition, it was found that DNA hybridization efficiency could be enhanced or decreased when DNA probes stood straight up or lay flat on the gold surface, depending on the potential of the gold substrate. The enhancement of DNA hybridization efficiency reached the maximum when surface coverage reached 5.87 x 10(12) molecules/cm(2) and the potential of gold substrate was more negative than -0.7 V (versus ITO-coated glass). The research may be helpful for the construction of sensitive biosensors, biochips, and nanoscale electronic devices.
通过表面等离子体共振（SPR）技术，以非接触、无标记模式研究了施加电场引发的DNA单分子层在“平躺”和“直立”状态之间的转换，以及随后在不同状态下的DNA杂交。结果表明，电场强度和表面覆盖率会影响DNA单分子层的转换。此外，研究发现，取决于金基底的电位，当DNA探针直立在金表面或平躺时，DNA杂交效率可能会提高或降低。当表面覆盖率达到5.87×10(¹²) 分子/cm²且金基底的电位比-0.7 V（相对于涂有ITO的玻璃）更负时，DNA杂交效率的提高达到最大值。该研究可能有助于构建灵敏的生物传感器、生物芯片和纳米级电子器件。
