Bonthuis Douwe Jan, Meyer Christine, Stein Derek, Dekker Cees
Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
Phys Rev Lett. 2008 Sep 5;101(10):108303. doi: 10.1103/PhysRevLett.101.108303.
Using laser fluorescence microscopy, we study the shape and dynamics of individual DNA molecules in slitlike nanochannels confined to a fraction of their bulk radius of gyration. With a confinement size spanning 2 orders of magnitude, we observe a transition from the de Gennes regime to the Odijk regime in the scaling of both the radius of gyration and the relaxation time. The radius of gyration and the relaxation time follow the predicted scaling in the de Gennes regime, while, unexpectedly, the relaxation time shows a sharp decrease in the Odijk regime. The radius of gyration remains constant in the Odijk regime. Additionally, we report the first measurements of the effect of confinement on the shape anisotropy.
利用激光荧光显微镜，我们研究了限制在其本体回转半径一部分的狭缝状纳米通道中单个DNA分子的形状和动力学。在限制尺寸跨越2个数量级的情况下，我们观察到在回转半径和弛豫时间的标度方面从德热纳 regime 到奥迪克 regime 的转变。回转半径和弛豫时间在德热纳 regime 中遵循预测的标度，而出乎意料的是，弛豫时间在奥迪克 regime 中急剧下降。回转半径在奥迪克 regime 中保持恒定。此外，我们报告了关于限制对形状各向异性影响的首次测量。
