Electrochemical quantification of accelerated FADGDH rates in aqueous nanodroplets
Electrochemical quantification of accelerated FADGDH rates in aqueous nanodroplets
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DOI：
10.1073/pnas.2025726118
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发表时间：
2021-06-22
影响因子：
11.1
通讯作者：
Dick, Jeffrey E.
中科院分区：
文献类型：
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作者：
Vannoy, Kathryn J.;Lee, Inyoung;Dick, Jeffrey E.
酶是催化对生命至关重要的反应的分子。这些催化剂通常在本体水中研究，其中水体积对反应性的影响被忽略。在这里，我们证明了速率增强高达两个数量级的酶被困在亚微米水悬浮在1，2-二氯乙烷纳米液滴。当单个纳米液滴不可逆地吸附到超微电极表面上时，如果超微电极产生酶辅因子，则在电流-时间曲线中酶活性是明显的。通过积分电流-时间响应并使用法拉第定律，可以容易地获得纳米液滴体积。单纳米滴技术使我们能够绘制酶的活性作为纳米滴大小的函数，揭示了强烈的反比关系。有限元模拟证实了我们的实验结果，并提供影响单纳米液滴酶学参数的见解。这些结果提供了一个框架，深刻影响在纳米尺度上的化学反应的理解。
Enzymes are molecules that catalyze reactions critical to life. These catalysts are often studied in bulk water, where the influence of water volume on reactivity is neglected. Here, we demonstrate rate enhancement of up to two orders of magnitude for enzymes trapped in submicrometer water nanodroplets suspended in 1,2-dichloroethane. When single nanodroplets irreversibly adsorb onto an ultramicroelectrode surface, enzymatic activity is apparent in the amperometric current-time trace if the ultramicroelectrode generates the enzyme cofactor. Nanodroplet volume is easily accessible by integrating the current-time response and using Faraday's Law. The single nanodroplet technique allows us to plot the enzyme's activity as a function of nanodroplet size, revealing a strong inverse relationship. Finite element simulations confirm our experimental results and offer insights into parameters influencing single nanodroplet enzymology. These results provide a framework to profoundly influence the understanding of chemical reactivity at the nanoscale.