Electrochemical Signal‐triggered Release of Biomolecules Functionalized with His‐tag Units

Abstract

Abstract His‐tagged molecular species, a ferrocene derivative and Protein A, were immobilized on electrode surfaces (Au and graphite) through formation of a chelated complex in the presence of Cu 2+ cations used as bridging units. The complex was cleaved and the attached molecules were released from the electrode surface by applying reductive potential to the electrodes resulting in Cu 2+ reduction, thus decomposing the chelate complex. The molecule release process was followed by cyclic voltammetry in case of the ferrocene derivative. His‐tagged Protein A was additionally labeled with a fluorescent tag and its release was followed by fluorescence measurements in the solution and by impedance spectroscopy at the electrode. The studied release of the His‐tagged redox species and biomolecules was considered as a new generic approach to the signal‐controlled molecule release applicable in various biotechnological and biomedical applications.