Nanoporous surfaces are promising for label-free electrochemical biosensing. We formed nanopores directly on the electrode surface by means of assembling a dense layer of nonconductive nanoparticles. In our model affinity biosensor, covalent attachment of albumin protein on top of 40 nm polystyrene nanoparticles represented a capture of an analyte, resulting in blockage of the nanopores. Different bulk concentrations of the ferro/ferricyanide redox pair were probed by Faradaic electrochemical impedance spectroscopy and fast chronoamperometry. The character of the redox probe permeation towards the electrode surface differed in dependence on its concentration. These data were compared with the theoretical behavior of the free diffusion according to the Cottrell equation. Both the bulk concentration of the redox probe and the timescale of the experiment affected the performance of the electrochemical detection, demonstrating the importance of controlling these parameters in immunosensing applications.

CEITEC Central European Institute of Technology Masaryk University Kamenice 5 Brno 625 00 Czech Republic

CEITEC Central European Institute of Technology Masaryk University Kamenice 5 Brno 625 00 Czech Republic; Department of Biochemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic

CEITEC Central European Institute of Technology Masaryk University Kamenice 5 Brno 625 00 Czech Republic; Department of Chemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic

Department of Econometrics Faculty of Military Leadership University of Defence Šumavská 4 Brno 662 10 Czech Republic

Citace poskytuje Crossref.org

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