Detection of aptamer-protein interactions using QCM and electrochemical indicator methods

Electrochemical indicator methylene blue and differential pulse voltammetry allowing to determine charge transfer from electrode surface to the thrombin bounded on a DNA aptamer and thus to detect thrombin (1) with high selectivity in comparison with nonspecific binding caused by human IgG (2) or human serum albumin (HSA) (3). We report novel method of detection thrombin-aptamer interaction based on measurement the charge consumption from the electrode covered by DNA aptamers to an electrochemical indicator methylene blue (MB), that is bounded to a thrombin. The binding of thrombin to an aptamers has been detected also by QCM method in flow measuring cell. We showed that using MB it is possible to detect thrombin with high sensitivity and selectivity. © 2004 Elsevier Ltd. All rights reserved