Peroxygenase based sensor for aromatic compounds.
We report on the redox behaviour of the peroxygenase from Agrocybe aegerita (AaeAPO) which has been electrostatically immobilized in a matrix of chitosan-embedded gold nanoparticles on the surface of a glassy carbon electrode. AaeAPO contains a covalently bound heme-thiolate as the redox active group that exchanges directly electrons with the electrode via the gold nanoparticles. The formal potential E°' of AaeAPO in the gold nanoparticles-chitosan film was estimated to be -(286±9) mV at pH 7.0. The heterogeneous electron transfer rate constant (k(s)) increases from 3.7 in the scan rate range from 0.2 to 3.0 V s(-1) and level off at 63.7 s(-1). Furthermore, the peroxide-dependent hydroxylation of aromatic compounds was applied to develop a sensor for naphthalene and nitrophenol. The amperometric measurements of naphthalene are based on the indication of H(2)O(2) consumption. For the chitosan-embedded gold nanoparticle system, the linear range extends from 4 to 40 μM naphthalene with a detection limit of 4.0 μM (S/N=3) and repeatability of 5.7% for 40 μM naphthalene.
Peng
Lei
L
Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Golm, Germany.
Wollenberger
Ulla
U
Kinne
Matthias
M
Hofrichter
Martin
M
Ullrich
René
R
Scheibner
Katrin
K
Fischer
Anna
A
Scheller
Frieder W
FW
D055362:Agrocybe / Q000201:enzymology; D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D048271:Chitosan; D055664:Electrochemical Techniques; D004566:Electrodes; D004579:Electron Transport; D004800:Enzymes, Immobilized; D006046:Gold; D006841:Hydrocarbons, Aromatic / Q000032:analysis*; D053768:Metal Nanoparticles; D006899:Mixed Function Oxygenases; D009281:Naphthalenes / Q000032:analysis; D009596:Nitrophenols / Q000032:analysis
D004800:Enzymes, Immobilized; D006841:Hydrocarbons, Aromatic; D009281:Naphthalenes; D009596:Nitrophenols; C031721:naphthalene; D006046:Gold; D048271:Chitosan; D006899:Mixed Function Oxygenases; C022333:peroxygenase