功能化磁性纳米珠在滚环扩增 DNA 线圈中的固定化研究。

Investigation of immobilization of functionalized magnetic nanobeads in rolling circle amplified DNA coils.

机构信息

Division of Nanotechnology and Functional Materials, Department of Engineering Sciences, Uppsala University, The Angstrom Laboratory, Box 534, SE-751 21 Uppsala, Sweden.

出版信息

J Phys Chem B. 2010 Mar 18;114(10):3707-13. doi: 10.1021/jp911251k.

DOI:10.1021/jp911251k

PMID:20175549

Abstract

Immobilization characteristics for single-stranded oligonucleotide-functionalized magnetic beads with nominal sizes of 40, 80, 130, and 250 nm in rolling circle amplified (RCA) DNA coils is investigated by employing complex magnetization measurements, dynamic light scattering and fluorescence microscopy. It was found that larger beads in a polydisperse bead size distribution more easily immobilize in the RCA DNA coils than do smaller beads. This may be related to a higher oligonucleotide surface coverage for the larger beads. Furthermore, it was concluded that both bead size and oligonucleotide surface coverage determine whether beads immobilize to give isolated coils with beads or larger clusters of beads and coils. A small bead size and a low oligonucleotide surface coverage favor the first kind of immobilization behavior, whereas a large bead size and a high oligonucleotide surface coverage favor the other. The present findings could be used to optimize both size and surface functionalization of beads employed in substrate-free magnetic biosensors.

摘要

采用复磁强计、动态光散射和荧光显微镜研究了粒径分别为 40、80、130 和 250nm 的单链寡核苷酸功能化磁性珠在滚环扩增（RCA）DNA 线圈中的固定化特性。结果发现，在多分散的珠粒尺寸分布中，较大的珠粒比较小的珠粒更容易固定在 RCA DNA 线圈中。这可能与较大的珠粒具有更高的寡核苷酸表面覆盖率有关。此外，还得出结论，珠粒大小和寡核苷酸表面覆盖率决定了珠粒是否固定形成具有珠粒的孤立线圈，还是形成较大的珠粒和线圈簇。小珠粒尺寸和低寡核苷酸表面覆盖率有利于第一种固定化行为，而大珠粒尺寸和高寡核苷酸表面覆盖率有利于另一种固定化行为。本研究结果可用于优化无基质磁生物传感器中所用珠粒的尺寸和表面功能化。