TY  - JOUR
A1  - Jetzschmann, Katharina J.
A1  - Jagerszki, Gyula
A1  - Dechtrirat, Decha
A1  - Yarman, Aysu
A1  - Gajovic-Eichelmann, Nenad
A1  - Gilsing, Hans-Detlev
A1  - Schulz, Burkhard
A1  - Gyurcsanyi, Robert E.
A1  - Scheller, Frieder W.
T1  - Vectorially Imprinted Hybrid Nanofilm for Acetylcholinesterase Recognition
JF  - Advanced functional materials
N2  - Effective recognition of enzymatically active tetrameric acetylcholinesterase (AChE) is accomplished by a hybrid nanofilm composed of a propidium-terminated self-assembled monolayer (Prop-SAM) which binds AChE via its peripheral anionic site (PAS) and an ultrathin electrosynthesized molecularly imprinted polymer (MIP) cover layer of a novel carboxylate-modified derivative of 3,4-propylenedioxythiophene. The rebinding of the AChE to the MIP/Prop-SAM nanofilm covered electrode is detected by measuring in situ the enzymatic activity. The oxidative current of the released thiocholine is dependent on the AChE concentration from approximate to 0.04 x 10(-6) to 0.4 x 10(-6)m. An imprinting factor of 9.9 is obtained for the hybrid MIP, which is among the best values reported for protein imprinting. The dissociation constant characterizing the strength of the MIP-AChE binding is 4.2 x 10(-7)m indicating the dominant role of the PAS-Prop-SAM interaction, while the benefit of the MIP nanofilm covering the Prop-SAM layer is the effective suppression of the cross-reactivity toward competing proteins as compared with the Prop-SAM. The threefold selectivity gain provided by i) the shape-specific MIP filter, ii) the propidium-SAM, iii) signal generation only by the AChE bound to the nanofilm shows promise for assessing AChE activity levels in cerebrospinal fluid.
KW  - acetylcholinesterase
KW  - biomimetic sensors
KW  - molecularly imprinted electropolymers
KW  - peripheral anionic site
KW  - propidium
Y1  - 2015
U6  - https://doi.org/10.1002/adfm.201501900
SN  - 1616-301X
SN  - 1616-3028
VL  - 25
IS  - 32
SP  - 5178
EP  - 5183
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schöne, Anne-Christin
A1  - Richau, Klaus
A1  - Kratz, Karl
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Influence of Diurethane Linkers on the Langmuir Layer Behavior of Oligo[(rac-lactide)-co-glycolide]-based Polyesterurethanes
JF  - Macromolecular rapid communications
N2  - Three oligo[(rac-lactide)-co-glycolide] based polyesterurethanes (OLGA-PUs) containing different diurethane linkers are investigated by the Langmuir monolayer technique and compared to poly[(rac-lactide)-co-glycolide] (PLGA) to elucidate the influence of the diurethane junction units on hydrophilicity and packing motifs of these polymers at the air-water interface. The presence of diurethane linkers does not manifest itself in the Langmuir layer behavior both in compression and expansion experiments when monomolecular films of OLGA-PUs are spread on the water surface. However, the linker retard the evolution of morphological structures at intermediate compression level under isobaric conditions (with a surface pressure greater than 11 mN m(-1)) compared to the PLGA, independent on the chemical structure of the diurethane moiety. The layer thicknesses of both OLGA-PU and PLGA films decrease in the high compression state with decreasing surface pressure, as deduced from ellipsometric data. All films must be described with the effective medium approximation as water swollen layers.
KW  - Brewster angle microscopy
KW  - Langmuir monolayer
KW  - poly[(rac-lactide)-co-glycolide]
KW  - polyesterurethanes
KW  - spectroscopic ellipsometry
Y1  - 2015
U6  - https://doi.org/10.1002/marc.201500316
SN  - 1022-1336
SN  - 1521-3927
VL  - 36
IS  - 21
SP  - 1910
EP  - 1915
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Tanne, Johannes
A1  - Jeoung, Jae-Hun
A1  - Peng, Lei
A1  - Yarman, Aysu
A1  - Dietzel, Birgit
A1  - Schulz, Burkhard
A1  - Schad, Daniel
A1  - Dobbek, Holger
A1  - Wollenberger, Ursula
A1  - Bier, Frank Fabian
A1  - Scheller, Frieder W.
T1  - Direct Electron Transfer and Bioelectrocatalysis by a Hexameric, Heme Protein at Nanostructured Electrodes
JF  - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis
N2  - A nanohybrid consisting of poly(3-aminobenzenesulfonic acid-co-aniline) and multiwalled carbon nanotubes [MWCNT-P(ABS-A)]) on a gold electrode was used to immobilize the hexameric tyrosine-coordinated heme protein (HTHP). The enzyme showed direct electron transfer between the heme group of the protein and the nanostructured surface. Desorption of the noncovalently bound heme from the protein could be excluded by control measurements with adsorbed hemin on aminohexanthiol-modified electrodes. The nanostructuring and the optimised charge characteristics resulted in a higher protein coverage as compared with MUA/MU modified electrodes. The adsorbed enzyme shows catalytic activity for the cathodic H2O2 reduction and oxidation of NADH.
KW  - HTHP
KW  - Nanohybrid
KW  - Poylaniline
KW  - Multiwalled carbon nanotube
Y1  - 2015
U6  - https://doi.org/10.1002/elan.201500231
SN  - 1040-0397
SN  - 1521-4109
VL  - 27
IS  - 10
SP  - 2262
EP  - 2267
PB  - Wiley-VCH
CY  - Weinheim
ER  -