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Functionality of dielectrophoretically immobilized enzyme molecules
Author(s) -
Laux EvaMaria,
Kaletta Udo C.,
Bier Frank F.,
Wenger Christian,
Hölzel Ralph
Publication year - 2014
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201300447
Subject(s) - horseradish peroxidase , fluorescence , immobilized enzyme , chemistry , biosensor , enzyme , hydrogen peroxide , rhodamine , oxidizing agent , molecule , fluorescence microscope , enzyme assay , combinatorial chemistry , peroxidase , dielectrophoresis , chromatography , nanotechnology , materials science , biochemistry , electrode , organic chemistry , physics , quantum mechanics
The enzyme horseradish peroxidase has been immobilized on nanoelectrode arrays by alternating current dielectrophoresis (DEP). Preservation of its enzymatic function after field application was demonstrated by oxidizing dihydrorhodamine 123 with hydrogen peroxide as co‐oxidant to create its fluorescent form, rhodamine 123 (Rh123). Localization of the fluorescently labeled enzyme and its product was conducted by fluorescence microscopy. Nanoelectrodes were prepared as tungsten pins arranged in square arrays. Experimental parameters for dielectrophoretic immobilization were optimized for even enzyme distribution and for enzymatic efficiency. Enzyme activity was quantified by determination of fluorescence intensities of immobilized enzyme molecules and of Rh123 produced. These results demonstrate that DEP can be applied to immobilize enzyme molecules while retaining their activity and rendering any chemical modifications unnecessary. This introduces a novel way for the preparation of bioactive surfaces for processes such as biosensing.