Novel dendrimers containing redox mediator: Enzyme immobilization and applications

Abstract

In this study, new dendrimers with a ferrocene core were produced by means of a divergent method for the immobilization of the glucose oxidase enzyme (GOx). Pt(II) and Pt(IV) ions were attached to the terminal groups of dendrimers. Metal-containing dendrimers, [Fc(MGlu)(2)-Aph-Pt(II)] and [Fc(MGlu)(2)-Aph-Pt(IV)], were obtained using the template method with aminophenol and Pt(II)/Pt(IV) cations. These compounds have been characterized by molar conductivity, magnetic susceptibility, FTIR, UV-Vis, H-1 NMR and LC-MS methods. The GOx enzyme was immobilized on the Fc(MGlu)(2), [Fc(MGlu)(2)-Aph-Pt(II)] and [Fc(MGlu)(2)-Aph-Pt(IV)] dendrimers, and the immobilized enzyme optimization parameters (substrate concentration, temperature, pH, reusability and storage capacity) were determined. Their K-m (mM) and V-max (mM.min(-1)) values were calculated from the Michaelis-Menten equation. The reusability of the immobilized glucose oxidase enzyme was investigated in an artificial urine medium. The research showed that [Fc(MGlu)(2)-Aph-Pt(II)] retains more than 61.23% of its initial activity after 10 successive cycles, which is a remarkable result. (C) 2019 Elsevier B.V. All rights reserved.