Peng, L.L.PengWollenberger, U.U.WollenbergerKinne, M.M.KinneHofrichter, M.M.HofrichterUllrich, R.R.UllrichScheibner, K.K.ScheibnerFischer, A.A.FischerScheller, F.W.F.W.Scheller2022-03-042022-03-042010https://publica.fraunhofer.de/handle/publica/22367310.1016/j.bios.2010.07.075We 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 3.0Vs-1 and level off at 63.7s-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 40M naphthalene with a detection limit of 4.0M (S/N=3) and repeatability of 5.7% for 40M naphthalene.en610660journal article