Sönnichsen Carsten, Reinhard Björn M, Liphardt Jan, Alivisatos A Paul
Department of Chemistry, University of California, Berkeley, California 94720.
Nat Biotechnol. 2005 Jun;23(6):741-5. doi: 10.1038/nbt1100. Epub 2005 May 22.
Forster Resonance Energy Transfer has served as a molecular ruler that reports conformational changes and intramolecular distances of single biomolecules. However, such rulers suffer from low and fluctuating signal intensities, limited observation time due to photobleaching, and an upper distance limit of approximately 10 nm. Noble metal nanoparticles have plasmon resonances in the visible range and do not blink or bleach. They have been employed as alternative probes to overcome the limitations of organic fluorophores, and the coupling of plasmons in nearby particles has been exploited to detect particle aggregation by a distinct color change in bulk experiments. Here we demonstrate that plasmon coupling can be used to monitor distances between single pairs of gold and silver nanoparticles. We followed the directed assembly of gold and silver nanoparticle dimers in real time and studied the kinetics of single DNA hybridization events. These "plasmon rulers" allowed us to continuously monitor separations of up to 70 nm for >3,000 s.
福斯特共振能量转移一直作为一种分子尺，用于报告单个生物分子的构象变化和分子内距离。然而，这种分子尺存在信号强度低且波动、由于光漂白导致观察时间有限以及约10纳米的上限距离等问题。贵金属纳米颗粒在可见光范围内具有等离子体共振，且不会闪烁或漂白。它们已被用作替代探针以克服有机荧光团的局限性，并且在整体实验中，利用附近颗粒中等离子体的耦合通过明显的颜色变化来检测颗粒聚集。在此，我们证明等离子体耦合可用于监测单对金和银纳米颗粒之间的距离。我们实时跟踪了金和银纳米颗粒二聚体的定向组装，并研究了单个DNA杂交事件的动力学。这些“等离子体尺”使我们能够在超过3000秒的时间内连续监测高达70纳米的间距。
