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Electrochemical Aptasensor Based on ZnO Modified Gold Electrode
Author(s) -
Evtugyn Gennady,
Cherkina Uljana,
Porfireva Anna,
Danzberger Jürgen,
Ebner Andreas,
Hianik Tibor
Publication year - 2013
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201300195
Subject(s) - ferricyanide , dielectric spectroscopy , cyclic voltammetry , detection limit , electrode , electrochemistry , aptamer , adsorption , analytical chemistry (journal) , nanorod , materials science , redox , chemistry , inorganic chemistry , nanotechnology , chromatography , biology , genetics
We developed an electrochemical thrombin aptasensor based on ZnO nanorods functionalized by electrostatically adsorption of 30‐mer DNA aptamers. The sensor surface was characterized by AFM and SEM. The surface layer assembling was optimized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) with ferricyanide ions as redox markers. The peak current of the ferricyanide and the charge transfer resistance gradually decreased with increasing concentration of thrombin in the range from 3 pM to 100 nM due to formation of aptamer‐thrombin complexes and slower diffusion of the marker ions through the surface layer. At optimal conditions, a limit of detection ( LOD ) of 3 pM for EIS measurements and 10 pM for CV response was calculated from the S/N =3.