Instituto de Catalisis y Petroleoquimica, CSIC, c/Marie Curie 2, L10, 28049 Madrid, Spain.
J Am Chem Soc. 2012 Oct 17;134(41):17212-20. doi: 10.1021/ja307308j. Epub 2012 Oct 4.
Direct electron transfer (DET) reactions between redox enzymes and electrodes can be maximized by oriented immobilization of the enzyme molecules onto an electroactive surface modified with functionalized gold nanoparticles (AuNPs). Here, we present such strategy for obtaining a DET-based laccase (Lc) cathode for O(2) electroreduction at low overpotentials. The stable nanostructured enzymatic electrode is based on the step-by-step covalent attachment of AuNPs and Lc molecules to porous graphite electrodes using the diazonium salt reduction strategy. Oriented immobilization of the enzyme molecules on adequately functionalized AuNPs allows establishing very fast DET with the electrode via their Cu T1 site. The measured electrocatalytic waves of O(2) reduction can be deconvoluted into two contributions. The one at lower overpotentials corresponds to immobilized Lc molecules that are efficiently wired by the AuNPs with a heterogeneous electron transfer rate constant k(0) ≫ 400 s(-1).
直接电子转移（DET）反应在氧化还原酶和电极之间可以通过将酶分子定向固定在功能化的金纳米粒子（AuNPs）修饰的电活性表面上来最大化。在这里，我们提出了一种基于这种策略的获得基于 DET 的漆酶（Lc）阴极的方法，用于在低过电势下进行 O（2）电还原。稳定的纳米结构酶电极是基于使用重氮盐还原策略将 AuNPs 和 Lc 分子逐步共价附着到多孔石墨电极上而获得的。酶分子在适当功能化的 AuNPs 上的定向固定允许通过它们的 Cu T1 位点与电极建立非常快速的 DET。测量的 O（2）还原的电化学催化波可以解卷积为两个贡献。在较低过电势下的一个对应于固定化的 Lc 分子，其通过 AuNPs 进行有效的布线，具有不均匀电子转移速率常数 k（0）≫400 s（-1）。
