Biomedical Engineering Department, University of Michigan 1101 Beal Avenue Ann Arbor, MI 48109 USA; Department of Biological Engineering, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.
Biomedical Engineering Department, University of Michigan 1101 Beal Avenue Ann Arbor, MI 48109 USA.
Biosens Bioelectron. 2011 May 15;26(9):3870-5. doi: 10.1016/j.bios.2011.02.049. Epub 2011 Mar 5.
We synthesized and characterized small yet highly robust silica-coated quantum dots (QDs) and then used them to develop highly sensitive molecular beacon (MB) for DNA detection. As compared to the previously reported methods, our silica coating approach enabled simple and rapid synthesis of silica-coated QDs in large quantities and high concentrations with a well-controlled silica layer. The QDs such made were stable and had a high quantum yield in a wide range of pH values (1-14) and high salt concentrations (up to 2 M). They were less than 10 nm in diameter, much smaller than current silica-coated QDs, thus allowing for efficient energy transfer. The MB sensor based on these silica-coated QDs was capable of rapidly detecting the target DNA at 0.1 nM concentration within 15 min. It could also differentiate the target DNA from the single base mismatched DNA. The QD-MB developed in this work can be used for highly sensitive and selective detection of DNA and other biomolecules in homogeneous solution and inside a cell, as well as in harsh environment.
我们合成并表征了小而高度稳定的硅壳量子点（QD），然后利用它们开发了用于 DNA 检测的高灵敏度分子信标（MB）。与之前报道的方法相比，我们的硅壳合成方法能够简单快速地大量合成高浓度的硅壳 QD，并且具有良好控制的硅壳层。这样制备的 QD 在很宽的 pH 值（1-14）和高盐浓度（高达 2 M）范围内稳定，量子产率高。它们的直径小于 10nm，比目前的硅壳 QD 小得多，因此能够实现高效的能量转移。基于这些硅壳 QD 的 MB 传感器能够在 15 分钟内快速检测到 0.1 nM 浓度的靶 DNA，并且能够区分靶 DNA 与单碱基错配 DNA。本工作中开发的 QD-MB 可用于均相溶液和细胞内以及恶劣环境中 DNA 和其他生物分子的高灵敏度和选择性检测。
