Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, The Netherlands.
Nat Commun. 2013;4:1667. doi: 10.1038/ncomms2688.
Studying and controlling reactions at surfaces is of great fundamental and applied interest in, among others, biology, electronics and catalysis. Because reaction kinetics is different at surfaces compared with solution, frequently, solution-characterization techniques cannot be used. Here we report solution gradients, prepared by electrochemical means, for controlling and monitoring reactivity at surfaces in space and time. As a proof of principle, electrochemically derived gradients of a reaction parameter (pH) and of a catalyst (Cu(I)) have been employed to make surface gradients on the micron scale and to study the kinetics of the (surface-confined) imine hydrolysis and the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition, respectively. For both systems, the kinetic data were spatially visualized in a two-dimensional reactivity map. In the case of the copper(I)-catalysed azide-alkyne 1,3-dipolar cycloaddition, the reaction order (2) was deduced from it.
在生物学、电子学和催化等领域，研究和控制表面反应具有重要的基础和应用意义。由于表面反应动力学与溶液中的反应动力学不同，因此通常不能使用溶液特性分析技术。在这里，我们报告了通过电化学手段制备的溶液梯度，用于控制和监测表面在空间和时间上的反应性。作为原理验证，我们利用电化学衍生的反应参数（pH 值和催化剂（Cu（I））梯度来实现微米尺度的表面梯度，并分别研究（表面限制的）亚胺水解和铜（I）催化的叠氮化物-炔烃 1,3-偶极环加成的动力学。对于这两个体系，我们都通过二维反应图可视化了动力学数据。对于铜（I）催化的叠氮化物-炔烃 1,3-偶极环加成反应，我们从动力学数据中推断出反应级数（2）。
