Label-free, single-molecule detection with optical microcavities
Label-free, single-molecule detection with optical microcavities
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DOI：
10.1126/science.1145002
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发表时间：
2007-08-10
期刊：
影响因子：
56.9
通讯作者：
Vahala, Kerry J.
中科院分区：
文献类型：
--
作者：
Armani, Andrea M.;Kulkarni, Rajan P.;Vahala, Kerry J.
目前的单分子检测技术需要标记目标分子。我们报道了一种基于超高质量(Q)因子（qbbb1010(8)）低语廊微腔的高特异性和灵敏度光学传感器。二氧化硅表面被功能化以结合目标分子；结合是通过共振波长位移检测的。单分子检测是通过观察单分子结合事件使共振频率发生位移，以及通过对许多结合事件的这些位移的统计来证实的。这些变化是由热光学机制引起的。此外，在血清中无标记、单分子检测到白细胞介素-2。这些实验证明了浓度的动态范围为10(12)，建立了微腔作为一个敏感和通用的检测器。
Current single-molecule detection techniques require labeling the target molecule. We report a highly specific and sensitive optical sensor based on an ultrahigh quality (Q) factor (Q > 10(8)) whispering-gallery microcavity. The silica surface is functionalized to bind the target molecule; binding is detected by a resonant wavelength shift. Single-molecule detection is confirmed by observation of single-molecule binding events that shift the resonant frequency, as well as by the statistics for these shifts over many binding events. These shifts result from a thermo-optic mechanism. Additionally, label-free, single-molecule detection of interleukin-2 was demonstrated in serum. These experiments demonstrate a dynamic range of 10(12) in concentration, establishing the microcavity as a sensitive and versatile detector.