@article{DongmoLeykDoscheetal.2016, author = {Dongmo, Saustin and Leyk, Janina and Dosche, Carsten and Richter-Landsberg, Christiane and Wollenberger, Ursula and Wittstock, Gunther}, title = {Electrogeneration of O-2(center dot-) and H2O2 Using Polymer-modified Microelectrodes in the Environment of Living Cells}, series = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis}, volume = {28}, journal = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1040-0397}, doi = {10.1002/elan.201600267}, pages = {2400 -- 2407}, year = {2016}, abstract = {Microelectrodes modified with electropolymerized plumbagin (PLG) were used for the generation of superoxide radical (O-2(center dot-)) and hydrogen peroxide (H2O2) during oxygen reduction reaction (ORR) in an aqueous medium, specifically in serum-free cell culture media. This is enabled by the specific design of a polymer film on the microelectrode. The generation and diffusion of O-2(center dot-) during electrocatalytic ORR at a positionable PLG polymer-modified microelectrode was followed by fluorescence microscopy with the selective dye 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and by amperometric detection using a cytochrome c-modified electrode at + 0.13 V. H2O2 production, either by direct oxygen reduction or as product of O-2(center dot-) disproportionation, was monitored by the reaction with Amplex UltraRed. The PLG polymer-modified microelectrodes were used to expose mammalian B6-RPE07 retinal cells to defined local fluxes of reactive oxygen species (ROS), and cellular responses and morphological alterations were observed. The use of a controllable source of ROS opens many possibilities to study how living cells respond to the presence of a certain flux of specific ROS.}, language = {en} }