Selective functionalization of independently addressed microelectrodes by electrochemical activation and deactivation of a coupling catalyst
Selective functionalization of independently addressed microelectrodes by electrochemical activation and deactivation of a coupling catalyst
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DOI：
10.1021/ja058380h
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发表时间：
2006-02-15
影响因子：
15
通讯作者：
Collman, JP
中科院分区：
文献类型：
--
作者：
Devaraj, NK;Dinolfo, PH;Collman, JP
我们展示了选择性功能化的独立寻址微电极通过电化学激活和失活的偶联催化剂。末端乙炔和有机叠氮化物之间的1,2,3-三唑生成是由铜(I)配合物（Sharpless“click”反应）有效催化的，而氧化的铜（II）配合物是无活性的。通过电化学激活或失活催化剂，通过切换其氧化还原状态，我们证明了控制三唑在表面固定叠氮化物和乙基二茂铁之间的形成。使用亚微摩尔浓度的反应物和催化剂，反应在分钟的时间尺度上进行，催化剂的活化和失活需要温和的电位，并且在水和混合水有机溶剂中有效。通过对每个电极进行适当的偏置，我们选择性地修饰了两个化学性质相同的10 μm宽电极中的一个，电极间距为10 μm。通过电寻址开启或关闭反应的能力以及该反应的化学选择性使Cu(I)催化三唑形成成为多电极阵列化学修饰的理想方法。
We demonstrate selective functionalization of independently addressed microelectrodes by electrochemical activation and deactivation of a coupling catalyst. 1,2,3-Triazole formation between terminal acetylenes and organic azides is efficiently catalyzed by copper(I) complexes (a Sharpless “click” reaction), while the oxidized copper(II) complexes are inactive. By electrochemically activating or deactivating the catalyst by switching its redox state, we demonstrate control over triazole formation between surface-immobilized azides and ethynylferrocene. The reaction proceeds on the time scale of minutes using submicromolar concentration of reactants and catalyst, requires mild potentials for catalyst activation and deactivation, and works in aqueous and mixed aqueous−organic solvents. By appropriate biasing of each electrode, we selectively modify one of two chemically identical 10-μm-wide electrodes separated by 10 μm in an interdigitated array. The ability to switch on or off the reaction by electrical addressing together with the chemoselectivity of this reaction makes Cu(I)-catalyzed triazole formation an ideal method for the chemical modification of multielectrode arrays.