TY  - JOUR
A1  - Comminges, Clement
A1  - Frasca, Stefano
A1  - Suetterlin, Martin
A1  - Wischerhoff, Erik
A1  - Laschewsky, André
A1  - Wollenberger, Ursula
T1  - Surface modification with thermoresponsive polymer brushes for a switchable electrochemical sensor
JF  - RSC Advances
N2  - Elaboration of switchable surfaces represents an interesting way for the development of a new generation of electrochemical sensors. In this paper, a method for growing thermoresponsive polymer brushes from a gold surface pre-modified with polyethyleneimine (PEI), subsequent layer-by-layer polyelectrolyte assembly and adsorption of a charged macroinitiator is described. We propose an easy method for monitoring the coil-to-globule phase transition of the polymer brush using an electrochemical quartz crystal microbalance with dissipation (E-QCM-D). The surface of these polymer modified electrodes shows reversible switching from the swollen to the collapsed state with temperature. As demonstrated from E-QCM-D measurements using an original signal processing method, the switch is operating in three reversible steps related to different interfacial viscosities. Moreover, it is shown that the one electron oxidation of ferrocene carboxylic acid is dramatically affected by the change from the swollen to the collapsed state of the polymer brush, showing a spectacular 86% decrease of the charge transfer resistance between the two states.
Y1  - 2014
U6  - https://doi.org/10.1039/c4ra07190e
SN  - 2046-2069
VL  - 4
IS  - 81
SP  - 43092
EP  - 43097
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Vergani, Marco
A1  - Carminati, Marco
A1  - Ferrari, Giorgio
A1  - Landini, Ettore
A1  - Caviglia, Claudia
A1  - Heiskanen, Arto
A1  - Comminges, Clement
A1  - Zor, Kinga
A1  - Sabourin, David
A1  - Dufva, Martin
A1  - Dimaki, Maria
A1  - Raiteri, Roberto
A1  - Wollenberger, Ursula
A1  - Emneus, Jenny
A1  - Sampietro, Marco
T1  - Multichannel bipotentiostat integrated with a microfluidic platform for electrochemical real-time monitoring of cell cultures
JF  - IEEE Transactions on biomedical circuits and systems
N2  - An electrochemical detection system specifically designed for multi-parameter real-time monitoring of stem cell culturing/differentiation in a microfluidic system is presented. It is composed of a very compact 24-channel electronic board, compatible with arrays of microelectrodes and coupled to a microfluidic cell culture system. A versatile data acquisition software enables performing amperometry, cyclic voltammetry and impedance spectroscopy in each of the 12 independent chambers over a 100 kHz bandwidth with current resolution down to 5 pA for 100 ms measuring time. The design of the platform, its realization and experimental characterization are reported, with emphasis on the analysis of impact of input capacitance (i.e., microelectrode size) and microfluidic pump operation on current noise. Programmable sequences of successive injections of analytes (ferricyanide and dopamine) and rinsing buffer solution as well as the impedimetric continuous tracking for seven days of the proliferation of a colony of PC12 cells are successfully demonstrated.
KW  - Electrochemical measurements
KW  - impedance spectroscopy
KW  - microfluidics
KW  - multichannel potentiostat
KW  - stem cell monitoring
Y1  - 2012
U6  - https://doi.org/10.1109/TBCAS.2012.2187783
SN  - 1932-4545
VL  - 6
IS  - 5
SP  - 498
EP  - 507
PB  - Inst. of Electr. and Electronics Engineers
CY  - Piscataway
ER  - 
TY  - GEN
A1  - Comminges, Clément
A1  - Frasca, Stefano
A1  - Sütterlin, Martin
A1  - Wischerhoff, Erik
A1  - Laschewsky, André
A1  - Wollenberger, Ursula
T1  - Surface modification with thermoresponsive polymer brushes for a switchable electrochemical sensor
N2  - Elaboration of switchable surfaces represents an interesting way for the development of a new generation of electrochemical sensors. In this paper, a method for growing thermoresponsive polymer brushes from a gold surface pre-modified with polyethyleneimine (PEI), subsequent layer-by-layer polyelectrolyte assembly and adsorption of a charged macroinitiator is described. We propose an easy method for monitoring the coil-to-globule phase transition of the polymer brush using an electrochemical quartz crystal microbalance with dissipation (E-QCM-D). The surface of these polymer modified electrodes shows reversible switching from the swollen to the collapsed state with temperature. As demonstrated from E-QCM-D measurements using an original signal processing method, the switch is operating in three reversible steps related to different interfacial viscosities. Moreover, it is shown that the one electron oxidation of ferrocene carboxylic acid is dramatically affected by the change from the swollen to the collapsed state of the polymer brush, showing a spectacular 86% decrease of the charge transfer resistance between the two states.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 287 
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-99471
ER  -