TY - GEN A1 - Peng, Lei A1 - Wollenberger, Ulla A1 - Kinne, Matthias A1 - Hofrichter, Martin A1 - Ullrich, René A1 - Scheibner, Katrin A1 - Fischer, Anna A1 - Scheller, Frieder W. T1 - Peroxygenase based sensor for aromatic compounds T2 - Biosensors and Bioelectronics N2 - 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 (ks) 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 H2O2 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. KW - Peroxygenase KW - Direct electron transfer KW - Nanoparticles KW - Naphthalene biosensor KW - Bioelectrocatalysis Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?http://www.sciencedirect.com/science/article/pii/S0956566310004501 SN - 1873-4235 VL - 26 IS - 4 SP - 1432 EP - 1436 ER - TY - GEN A1 - Peng, Lei A1 - Wollenberger, Ulla A1 - Hofrichter, Martin A1 - Ullrich, René A1 - Scheibner, Katrin A1 - Scheller, Frieder W. T1 - Bioelectrocatalytic properties of Agrocybe aegerita peroxygenase T2 - Electrochimica Acta N2 - A biosensor for detecting the aromatic substance 4-nitrophenol based on Agrocybe aegerita peroxygenase (AaP) immobilized with chitosan-stabilized gold nanoparticles is presented here. This biosensor measures the enzymatic product of 4-nitrophenol peroxygenation, 4-nitrocatechol, which is electrochemically detected in the presence of hydrogen peroxide. Cyclic voltammetry and amperometry were used to characterize the proposed biosensor. The linear range of the AaP biosensor for the detection of 4-nitrophenol was between 10 and 30 μM with a detection limit of 0.2 μM (based on the S/N = 3). The catalytic property of AaP to oxidize 4-nitrophenol was compared with two other heme proteins, a camphor-hydroxylating cytochrome P450 monooxygenase (P450cam, CYP101) and horseradish peroxidase (HRP). The results revealed that only AaP is capable of catalyzing the hydroxylation of 4-nitrophenol into 4-nitrocatechol. Consequently, AaP could be a particularly potent biocatalyst that may fill the gap between cytochrome P450s and common heme peroxidases. KW - Peroxygenase KW - Cytochrome P450s KW - Horseradish peroxidase KW - 4-Nitrophenol KW - Agrocybe aegerita Y1 - 2010 UR - http://www.sciencedirect.com/science/article/pii/S0013468610000149 U6 - https://doi.org/10.1016/j.electacta.2009.12.065 SN - 0013-4686 VL - 55 IS - 27 SP - 7809 EP - 7813 ER -