TY - JOUR A1 - Lettau, Kristian A1 - Gajovic-Eichelmann, N. A1 - Kwak, Young-Keun A1 - Scheller, Frieder W. A1 - Warsinke, Axel T1 - Hydroxylasen und katalytische Polymere für Biochips Y1 - 2004 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Tiepner, K. A1 - Warsinke, Axel T1 - Anwendung von Biosensoren in der Lebensmittelanalytik Y1 - 2004 SN - 3-89947-120-2 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Warsinke, Axel A1 - Pfeiffer, Dorothea A1 - Czeponik, J. T1 - Biosensorik / Bioanalytik Y1 - 2004 SN - 3-87081-372-5 ER - TY - JOUR A1 - Lettau, Kristian A1 - Warsinke, Axel A1 - Laschewsky, André A1 - Mosbach, K. A1 - Yilmaz, E. A1 - Scheller, Frieder W. T1 - An esterolytic imprinted polymer prepared via a silica-supported transition state analogue N2 - In this work we describe a new preparation method for an esterolytic imprinted polymer with catalytic sites on the surface. A template was prepared by immobilizing a transition state analogue (phosphoramidic acid derivative) of an esterolytic reaction within porous silica particles. Polymerization within the pores was carried out using 4- vinylimidazole as a functional monomer and divinylbenzene as a cross-linker. The polymer was released by dissolution of the silica support with hydrofluoric acid and catalytic properties were studied by incubation with three different 4- nitrophenylesters and spectrophotometric determination of the released 4-nitrophenol. For 4-nitrophenyl acetate an activity of 211 nmol min(-1) mg(-1) and a K-m value of 2.2 mmol L-1 was obtained Y1 - 2004 ER - TY - JOUR A1 - Pieper-Fürst, U. A1 - Kleuser, U. A1 - Stöcklein, Walter F. M. A1 - Warsinke, Axel A1 - Scheller, Frieder W. T1 - Detection of subicomolar concentrations of human matrix metalloproteinase-2 by an optical biosensor N2 - We describe in this paper the development of a one-step sandwich assay for the highly sensitive and fast detection of human matrix metalloproteinase (MMP)-2 (EC 3.4.24.24), using surface plasmon resonance (SPR). For the assay, two ligands were selected: monoclonal anti-MMP-2 antibody Ab-2 and the tissue inhibitor of metalloproteinases (TIMP)-2. They were chosen on the basis of (1) their affinities to MMP-2, (2) the efficiency of immobilization to the sensor chip, (3) the efficiency of adsorption to colloidal gold, and (4) the stability of these protein-coated gold particles. The assay included mixing of MMP-2 with antibody Ab-2 adsorbed to colloidal gold with a diameter of about 20 rim and injection into the flowcell of the SPR instrument containing immobilized TIMP-2. By using colloidal gold particles an amplification factor of 114 and a detection limit of 0.5 pM for MMP-2 were obtained. The precision of the assay was high even at low analyte concentrations, the standard deviation being 8.3% for five determinations of 1 pM MMP- 2. No significant binding was observed with the structurally related MMP-9. The assay is far more sensitive and faster than commonly used methods for MMP-2 detection. As TIMP-bound MMP-2 is not detected by this method, the assay can be applied for measuring free MMP-2, reflecting the imbalance of free and inhibitor-bound enzyme in various pathological situations. (C) 2004 Elsevier Inc. All rights reserved Y1 - 2004 ER -