@article{LiuWollenbergerKatterleetal.2006, author = {Liu, Songqin and Wollenberger, Ursula and Katterle, Martin and Scheller, Frieder W.}, title = {Ferroceneboronic acid-based amperometric biosensor for glycated hemoglobin}, issn = {0925-4005}, doi = {10.1016/j.snb.2005.07.011}, year = {2006}, abstract = {An amperometric biosensor for the determination of glycated hemoglobin in human whole blood is proposed. The principle is based on the electrochemical measurement of ferroceneboronic acid (FcBA) that has been specifically bound to the glycated N-terminus. Hemoglobin is immobilized on a zirconium dioxide nanoparticle modified pyrolytic graphite electrode (PGE) in the presence of didodecyldimethylammonium bromide (DDAB). The incubation of this sensor in FcBA solution leads to the formation of an FcBA-modified surface due to the affinity interaction between boronate and the glycated sites of the hemoglobin. The binding of FcBA results in well-defined redox peaks with an E-0' of 0.299 V versus Ag/AgCl (1 M KCl). The square wave voltammetric response of the bound FcBA reflects the amount of glycated hemoglobin at the surface. This signal increases linearily with the degree of glycated hemoglobin from 6.8 to 14.0\% of total immobilized hemoglobin. The scheme was applied to the determination of the fraction of glycated hemoglobin in whole blood samples.}, language = {en} } @misc{ZorHeiskanenCavigliaetal.2014, author = {Z{\´o}r, K. and Heiskanen, A. and Caviglia, Claudia and Vergani, M. and Landini, E. and Shah, F. and Carminati, Marco and Mart{\´i}nez-Serrano, A. and Ramos Moreno, T. and Kokaia, M. and Benayahu, Dafna and Keresztes, Zs. and Papkovsky, D. and Wollenberger, Ursula and Svendsen, W. E. and Dimaki, M. and Ferrari, G. and Raiteri, R. and Sampietro, M. and Dufva, M. and Emn{\´e}us, J.}, title = {A compact multifunctional microfluidic platform for exploring cellular dynamics in real-time using electrochemical detection}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-99492}, pages = {11}, year = {2014}, abstract = {Downscaling of microfluidic cell culture and detection devices for electrochemical monitoring has mostly focused on miniaturization of the microfluidic chips which are often designed for specific applications and therefore lack functional flexibility. We present a compact microfluidic cell culture and electrochemical analysis platform with in-built fluid handling and detection, enabling complete cell based assays comprising on-line electrode cleaning, sterilization, surface functionalization, cell seeding, cultivation and electrochemical real-time monitoring of cellular dynamics. To demonstrate the versatility and multifunctionality of the platform, we explored amperometric monitoring of intracellular redox activity in yeast (Saccharomyces cerevisiae) and detection of exocytotically released dopamine from rat pheochromocytoma cells (PC12). Electrochemical impedance spectroscopy was used in both applications for monitoring cell sedimentation and adhesion as well as proliferation in the case of PC12 cells. The influence of flow rate on the signal amplitude in the detection of redox metabolism as well as the effect of mechanical stimulation on dopamine release were demonstrated using the programmable fluid handling capability. The here presented platform is aimed at applications utilizing cell based assays, ranging from e.g. monitoring of drug effects in pharmacological studies, characterization of neural stem cell differentiation, and screening of genetically modified microorganisms to environmental monitoring.}, language = {en} }