@article{KnoescheHalamekMakoweretal.2003,
  author    = {Kn{\"o}sche, Kristina and Hal{\´a}mek, Jan and Makower, Alexander and Fournier, Didier and Scheller, Frieder W.},
  title     = {Molecular recognition of cocaine by acetylcholinesterases for affinity purification and bio-sensing},
  year      = {2003},
  language  = {en}
}
@article{TellerHalamekMakoweretal.2006,
  author    = {Teller, C. and Halamek, Jan and Makower, Alexander and Fournier, Didier and Schulze, H. and Scheller, Frieder W.},
  title     = {A piezoelectric sensor with propidium as a recognition element for cholinesterases},
  doi       = {10.1016/j.snb.2005.02.053},
  year      = {2006},
  abstract  = {A piezoelectric biosensor has been developed on the basis of the reversible acetylcholinesterase (AChE) inhibitor propidium. The propidium cation was bound to a 11-mercaptoundecanoic acid monolayer on gold-coated quartz crystals. The immobilization was done via activation of carboxyl groups by 1,3-dicyclohexylcarbodiimide (DCC). Different types of cholinesterases (acetyl- and butyryl-ChE) from different origins were tested for their binding ability towards the immobilized propidium. Binding Studies were performed in a flow system, Furthermore, catalytically active and organophosphate-inhibited enzyme were compared re-aiding their binding capability. The binding constants were derived by using an one to one binding model and a refined model also including rebinding effects. It was shown that organophosphorylation of the active site hardly influences the affinity of AChE towards propidium. Furthermore the propidium-based biosensor provides equal sensitivity as compared with piezolelectric sensors with immobilized paraoxon- an active site ligand of AChE. (c) 2005 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{HalamekTellerZeraviketal.2006,
  author    = {Halamek, Jan and Teller, Carsten and Zeravik, Jiri and Fournier, Didier and Makower, Alexander and Scheller, Frieder W.},
  title     = {Characterization of binding of cholinesterases to surface immobilized ligands},
  issn      = {0003-2719},
  doi       = {10.1080/00032710600713107},
  year      = {2006},
  abstract  = {We summarize here the development of various piezoelectric biosensors utilizing cholinesterase (ChE) as the recognition element. In our work we studied the interaction between cholinesterase and its ligands (propidium, carnitine, benzylgonine-1,8-diamino-3,4-dioxaoctane (BZE-DADOO) and paraoxon). The sensor modification was based on a self-assembled monolayer (SAM) of a thiol compound (11-mercaptoundecanoic acid) on the gold electrode and the subsequent covalent coupling of the cholinesterase ligand to this SAM. The ligand-modified piezoelectric sensors were placed in a flow system to allow the on-line monitoring of cholinesterase binding and the enzymatic activity quantification by amperometry. Cholinesterases from different species-acetylcholinesterase (AChE) from Electrophorus electricus , AChE from Drosophila melanogaster , and butyrylcholinesterase (BChE) of human origin-were tested on the various immobilized ligands. Our research allowed the development of a competitive assay for the detection of organophosphates in river water samples using the BZE-DADOO-modified piezosensor. Another direction of research was pointed on the characterization of the interactions between ChE and its ligands. The kinetic binding constants were derived using a one- to-one binding model},
  language  = {en}
}
@article{HalamekTellerMakoweretal.2006,
  author    = {Halamek, Jan and Teller, Carsten and Makower, Alexander and Fournier, Didier and Scheller, Frieder W.},
  title     = {EQCN-based cholinesterase biosensors},
  issn      = {0013-4686},
  doi       = {10.1016/j.electacta.2006.03.047},
  year      = {2006},
  abstract  = {The binding of acetylcholinesterase (AChE) to a propidium-modified piezoelectric quartz crystal and its surface enzymatic activity have been investigated. Propidium binds to a site remote to the active center of AChE - the peripheral anionic site (PAS) - which is located on the rim of the gorge to the active site. The gold electrodes of the quartz crystal were first modified with 11-mercaptoundecanoic acid to which propidium was coupled. AChE binding was monitored by a quartz crystal nanobalance (QCN), followed by amperometric activity evaluation of the AChE loaded on the sensor. Interestingly, the binding is strong but does not inhibit AChE. However, an excess of propidium in solution inhibits the immobilized enzyme. The surface enzymatic activities observed depend on the amount of enzyme and differ according to the type and species, i.e. number of enzyme subunits (Electrophorus electricus tetrameric, Drosophila melanogaster mono- and dimeric form - DmAChE). The operational stability and regeneration, effect of propidium in solution and detection limit for substrate for various AChEs were investigated amperometrically.},
  language  = {en}
}