论文标题
用于无标签的单蛋白的紫外光角天线
Ultraviolet optical horn antennas for label-free detection of single proteins
论文作者
论文摘要
单分子荧光技术彻底改变了我们研究蛋白质的能力。但是，荧光标签的存在可以改变蛋白质结构和/或改变其与其他物种的反应。为了避免需要荧光标签，紫外线中蛋白质的固有自动荧光提供了荧光技术的好处，而无需引入标签缺点。不幸的是，迄今为止，蛋白质的低自荧光亮度极大地挑战了单分子检测。在这里，我们介绍了光角天线，这是一个专用的纳米光子平台，可实现紫外线中单蛋白的无标签检测。该设计结合了荧光等离子体增强，高效收集高达85 {\ textDegree}角度和背景筛选。我们从固定和扩散的单蛋白中检测到紫外线自荧光，并在变性后监测蛋白质展开和解离。光学角天线为荧光光谱的独特而有前途的形式开放，以实时研究其天然状态的单蛋白。
Single-molecule fluorescence techniques have revolutionized our ability to study proteins. However, the presence of a fluorescent label can alter the protein structure and/or modify its reaction with other species. To avoid the need for a fluorescent label, the intrinsic autofluorescence of proteins in the ultraviolet offers the benefits of fluorescence techniques without introducing the labelling drawbacks. Unfortunately, the low autofluorescence brightness of proteins has greatly challenged single molecule detection so far. Here we introduce optical horn antennas, a dedicated nanophotonic platform enabling the label-free detection of single proteins in the UV. This design combines fluorescence plasmonic enhancement, efficient collection up to 85{\textdegree} angle and background screening. We detect the UV autofluorescence from immobilized and diffusing single proteins, and monitor protein unfolding and dissociation upon denaturation. Optical horn antennas open up a unique and promising form of fluorescence spectroscopy to investigate single proteins in their native states in real time.
