Ulukan, Elifoeztuerk, Funda2024-10-292024-10-2920230026-92471434-4475https://doi.org/10.1007/s00706-023-03071-6https://hdl.handle.net/20.500.11776/14209In this study, an amperometric biosensor for hydrogen peroxide quantification was prepared by electrostatic immobilization of horseradish peroxidase on a multi-walled carbon nanotube, ionic liquid, and poly-L-histidine modified glassy carbon electrode. The immobilization of the horseradish peroxidase on the electrode surface was achieved by positive charges of poly-L-histidine. The surface morphology was analyzed by scanning electron microscopy, cyclic voltammetry, and impedance spectroscopy. The electrode composition, buffer pH, and operating potential were all optimized in order to achieve the best analytical performance. The modified electrode, which has been fabricated at its optimum composition, reveals two different linear working ranges, namely 2.0 x 10(-8) M to 9.1 x 10(-7) M and 1.8 x 10(-6) M to 1.8 x 10(-4) M, which are at the determined optimum operating conditions. The detection limit of the proposed method is of 2.9 x 10(-9) M. The analytical applicability of the amperometric determination of hydrogen peroxide concerning the developed biosensor has been evaluated by quantifying hydrogen peroxide in a commercial oxygenated water sample.{GRAPHICAL ABSTRACT}en10.1007/s00706-023-03071-6info:eu-repo/semantics/closedAccessBiosensorsElectrochemistryEnzymesHydrogen peroxidePoly-L-histidineArticle1546585594Q3WOS:0009818469000012-s2.0-85158139215Q3