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Electrochemical Quartz Crystal Microbalance Studies on Cytochrome c/Polyelectrolyte Multilayer Assemblies on Gold Electrodes
Author(s) -
Beissenhirtz M. K.,
Kafka J.,
Schäfer D.,
Wolny M.,
Lisdat F.
Publication year - 2005
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.200503319
Subject(s) - quartz crystal microbalance , polyelectrolyte , electrode , electron transfer , electrochemistry , layer by layer , chemical engineering , redox , cytochrome c , cyclic voltammetry , materials science , layer (electronics) , chemistry , analytical chemistry (journal) , inorganic chemistry , nanotechnology , chromatography , organic chemistry , polymer , biochemistry , adsorption , engineering , mitochondrion
Polyelectrolyte multilayer assemblies containing proteins are of interest for applications such as sensors, bioreactors, and bioelectronics. A multilayer electrode was built up by the layer‐by‐layer strategy consisting of alternating layers of cytochrome c and poly(aniline sulfonic acid). The electrode showed a linear increase of redox active protein with the number of deposited layers. The principle of electrode preparation was transferred from needle electrodes to planar surfaces in order to further the understanding of electron transfer through the layer assembly by means of electrochemical quartz crystal microbalance studies. The deposition process was followed on‐line by detection of the frequency shift of the crystals and was found to be rather fast (minutes). The total mass deposited was found to correlate well with the electrochemical response of the immobilized cyt.c. Furthermore, the influence of the polyelectrolyte was investigated by addition of PSS to the PASA solution. The strong interaction of the former polyelectrolyte seemed to hinder the electron transfer although a multilayer formation was proved. Dilution of the protein solution with redox inactive apo‐cyt.c led to a strong decrease of the voltammetric signal, well beyond the percentage of apo‐cyt.c inside the assembly. Thus, arguments for an electron transfer via protein–protein interaction were found.