Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Ionic Topochemical Tuned Biosensor Interface

: Nagel, B.; Gajovic-Eichelmann, N.; Scheller, F.W.; Katterle, M.


Langmuir. The ACS journal of surfaces and colloids 26 (2010), Nr.11, S.9088-9093
ISSN: 0743-7463
ISSN: 1520-5827
Fraunhofer IBMT ()

Two new hydrophilic, poly(ethylene glycol) (PEG)-based redox copolymers bearing electrochemically active ferrocene (Fc) and thiol/disulfide anchoring functionalities were synthesized. These copolymers are shown to adsorb on gold surfaces causing polymeric self-assembled monolayers (pSAMs) that possess triple functions: "redox-active", "ionic-tunable", and "bio-inert". Both immobilized polymers showed redox potentials at +400 mV (Ag|AgCl), and facilitate the electrocatalytical oxidation of NADH. Additionally, interfacial architecture of the polymers is affected by an increase in Ca2+ concentration, which leads to an amplification of the electrochemical response. The electrode current, measured for NADH-oxidation, increased by 80% after addition of 10 mM Ca2+ ions. Considering the Ca2+ influence on the heterogeneous electron transfer a structural model of the immobilized polymers is proposed based on the strong chelating abilitiy of noncyclic PEG moieties.