Optoplasmonic characterisation of reversible disulfide interactions at single thiol sites in the attomolar regime
Optoplasmonic characterisation of reversible disulfide interactions at single thiol sites in the attomolar regime
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DOI：
10.1038/s41467-020-15822-8
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发表时间：
2020-04-27
影响因子：
16.6
通讯作者：
Vollmer, Frank
中科院分区：
文献类型：
--
作者：
Vincent, Serge;Subramanian, Sivaraman;Vollmer, Frank
探索单个化学反应是绘制反应路径的关键。然而，由于反应动力学不可避免地受到干扰，亚kDa反应物和产物的痕量分析被标记混淆了。硫醇-二硫键交换反应因其在纳米技术和自然界中的许多应用而引起人们的特别兴趣。由于一些技术限制，单一硫醇和二硫化物的氧化还原循环一直无法解决，例如无法区分离开的基团。在这里，我们展示了使用无标记光致等离子体传感器来检测单分子硫醇-二硫化物交换。我们实时量化亚kDa硫化物种之间的重复反应，并将其浓度降至100‘S的大气分子。在我们的测量中采用了一种独特的传感方式，能够观察到等离子体纳米颗粒表面的单一二硫化物反应动力学和路径。我们的技术为通过光等离激元表征分子的电荷、氧化态和手性铺平了道路。可视化单分子反应，以了解其机制，是一项具有挑战性的任务。在这里，作者研究了通过无标记光致等离子体传感器固定在金纳米颗粒上的二硫化物与硫醇酸盐的交换反应，并检测了溶液中单独的二硫化物相互作用
Probing individual chemical reactions is key to mapping reaction pathways. Trace analysis of sub-kDa reactants and products is obfuscated by labels, however, as reaction kinetics are inevitably perturbed. The thiol-disulfide exchange reaction is of specific interest as it has many applications in nanotechnology and in nature. Redox cycling of single thiols and disulfides has been unresolvable due to a number of technological limitations, such as an inability to discriminate the leaving group. Here, we demonstrate detection of single-molecule thiol-disulfide exchange using a label-free optoplasmonic sensor. We quantify repeated reactions between sub-kDa thiolated species in real time and at concentrations down to 100's of attomolar. A unique sensing modality is featured in our measurements, enabling the observation of single disulfide reaction kinetics and pathways on a plasmonic nanoparticle surface. Our technique paves the way towards characterising molecules in terms of their charge, oxidation state, and chirality via optoplasmonics. Visualising single-molecule reactions, to understand their mechanisms, is a challenging task. Here, the authors investigate disulfide exchange reactions with thiolates immobilised on a gold nanoparticle through a label-free optoplasmonic sensor, and detect individual disulfide interactions in solution