title: Molecular assembly of redox-conductive ferrocene-streptavidin conjugates--towards bio-electrochemical devices.
abstract: Peptidic spacers, 0.4 and 2 nm in length, were used to couple ferrocene moieties to streptavidin. The resulting conjugates were immobilised on electrode surfaces using biotin binding. The electron transfer through multilayers of the conjugates is strongly dependent on the length of the spacer between the protein and the attached ferrocene. A monolayer of the long-linker conjugate immobilised on interdigitated microelectrode arrays was found to electrochemically bridge the 2 microm wide non-conductive gap between the electrodes. The redox current through the layer is dependent on external parameters such as the applied voltage difference between the two electrode arrays or the temperature. The long-range electrochemical conductivity in combination with the biotin binding capability is a prerequisite for the application of the conjugates in future bio-electrochemical devices.
authors.affiliation: Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. celestino.padeste@psi.ch
authors.forename: Celestino
authors.initials: C
authors.lastname: Padeste
authors.forename: Beat
authors.initials: B
authors.lastname: Steiger
authors.forename: Andreas
authors.initials: A
authors.lastname: Grubelnik
authors.forename: Louis
authors.initials: L
authors.lastname: Tiefenauer
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004553:Electric Conductivity; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D005296:Ferrous Compounds / Q000737:chemistry*; D008422:Materials Testing; D000075163:Metallocenes; D008839:Microelectrodes; D010084:Oxidation-Reduction; D011485:Protein Binding; D019809:Streptavidin / Q000737:chemistry*; D013696:Temperature
chemical_list: D020099:Coated Materials, Biocompatible; D005296:Ferrous Compounds; D000075163:Metallocenes; D019809:Streptavidin; C004998:ferrocene