Anomalous DNA hybridisation kinetics on gold nanorods revealed via a dual single-molecule imaging and optoplasmonic sensing platform
Anomalous DNA hybridisation kinetics on gold nanorods revealed via a dual single-molecule imaging and optoplasmonic sensing platform
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DOI：
10.1039/d3nh00080j
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发表时间：
2023-05-11
影响因子：
9.7
通讯作者：
Vollmer，Frank
中科院分区：
文献类型：
--
作者：
Eerqing，Narima;Wu，Hsin-Yu;Vollmer，Frank
观察固定在等离子体纳米粒子上的 DNA 探针的杂交动力学是弱发射物质的等离子体增强荧光检测和光等离子体传感器上基于折射率的单分子检测的关键。局部场在为单分子检测提供等离子体信号增强方面的作用已经得到了详细研究。然而，很少有研究比较这两种单分子研究技术的实验结果。在这里，我们开发了第一个光学装置，集成了光等离子和基于 DNA-PAINT 的寡核苷酸检测，以比较这些子平台并提供对单分子过程的补充见解。我们记录单个瞬时杂交事件的荧光和光等离子传感器信号。杂交事件在同一样品池中观察到较长时间（即朝向高结合位点占用）。报告了测量持续时间内关联率的下降。我们的双光等离子传感和成像平台可以深入了解观察到的现象，揭示不可逆杂交事件在光等离子传感中检测到的阶跃信号上累积。我们的结果指出了新的物理化学机制，可以使光激发等离子体纳米粒子上的 DNA 杂交稳定。
Observing the hybridisation kinetics of DNA probes immobilised on plasmonic nanoparticles is key in plasmon-enhanced fluorescence detection of weak emitting species, and refractive index based single-molecule detection on optoplasmonic sensors. The role of the local field in providing plasmonic signal enhancements for single-molecule detection has been studied in great detail. Nevertheless, few studies have compared the experimental results in both techniques for single-molecule studies. Here we developed the first optical setup that integrates optoplasmonic and DNA-PAINT based detection of oligonucleotides to compare these sub-platforms and provide complementary insights into single molecule processes. We record the fluorescence and optoplasmonic sensor signals for individual, transient hybridisation events. The hybridisation events are observed in the same sample cell and over a prolonged time (i.e. towards high binding site occupancies). A decrease in the association rate over the measurement duration is reported. Our dual optoplasmonic sensing and imaging platform offers insight into the observed phenomenon, revealing that irreversible hybridisation events accumulate over detected step signals in optoplasmonic sensing. Our results point to novel physicochemical mechanisms that result in the stabilisation of DNA hybridisation on optically-excited plasmonic nanoparticles.