High-Throughput Synthesis and Electrochemical Screening of a Library of Modified Electrodes for NADH Oxidation

Aleksandra Pinczewska, Maciej Sosna, Sally Bloodworth, Jeremy Dunbar Kilburn, Philip N. Bartlett

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

We report the combinatorial preparation and high-throughput screening of a library of modified electrodes designed to catalyze the oxidation of NADH. Sixty glassy carbon electrodes were covalently modified with ruthenium(II) or zinc(II) complexes bearing the redox active 1,10-phenanthroline-5,6-dione (phendione) ligand by electrochemical functionalization using one of four different linkers, followed by attachment of one of five different phendione metal complexes using combinatorial solid-phase synthesis methodology. This gave a library with three replicates of each of 20 different electrode modifications. This library was electrochemically screened in high-throughput (HTP) mode using cyclic voltammetry. The members of the library were evaluated with regard to the surface coverage, midpeak potential, and voltammetric peak separation for the phendione ligand, and their catalytic activity toward NADH oxidation. The surface coverage was found to depend on the length and flexibility of the linker and the geometry of the metal complex. The choices of linker and metal complex were also found to have significant impact on the kinetics of the reaction between the 1,10-phenanthroline-5,6-dione ligand and NADH. The rate constants for the reaction were obtained by analyzing the catalytic currents as a function of NADH concentration and scan rate, and the influence of the surface molecular architecture on the kinetics was evaluated.

Original languageEnglish
Pages (from-to)18022-18033
Number of pages12
JournalJournal of the American Chemical Society
Volume134
Issue number43
DOIs
Publication statusPublished - 31 Oct 2012

Keywords

  • GLASSY-CARBON ELECTRODES
  • CHEMICALLY MODIFIED ELECTRODES
  • PHASE SYNTHESIS METHODOLOGIES
  • ELECTROCATALYTIC OXIDATION
  • COVALENT MODIFICATION
  • DIAZONIUM SALTS
  • 1,10-PHENANTHROLINE-5,6-DIONE COMPLEXES
  • OSMIUM PHENANTHROLINEDIONE
  • REDUCTION POTENTIALS
  • GRAPHITE-ELECTRODES

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