Proteins modified with DNAzymes or aptamers act as biosensors or biosensor labels

Hybrid systems composed of a glucose oxidase (GOx)/peroxidase-mimicking DNAzyme, and of microperoxidase-11 (MP-11)/anti-thrombin aptamer were synthesized. The hybrid systems were employed as amplifying labels for the colorimetric or chemiluminescence detection of an enzyme functions, and thrombin analysis, respectively. In the GOx/DNAzyme system, the GOx-mediated oxidation of glucose led to the formation of H2O2, and this activated the oxidation of ABTS to a colored product, or to the generation of chemiluminescence in the presence of luminol. The MP-11/anti-thrombin aptamer enabled the amplified analysis of thrombin by the MP-11-mediated generation of chemiluminescence in the presence of luminol/H2O2. (c) 2006 Elsevier B.V. All rights reserved.