Authors: J. Dong and B.A. Parviz
Affilation: University of Washington, United States
Pages: 481 - 484
Keywords: self-assembled monolayer, protein, electrochemical sensor, nanoelectrode
The enzyme thrombin plays a crucial role in the regulation of blood coagulation. We present a sensor that can directly detect this enzyme and generate an electronic signal. The sensor structure consists of three electrodes that are partially exposed to the environment under test. A bias voltage is applied between the larger counter electrode and two smaller working and control electrodes and the current passing through the electrodes and the test medium is monitored. The surface of the working electrode is functionalized with a custom-designed aptamer receptor molecule that can specifically bind to the thrombin. The preferential binding of the enzyme to the working electrode changes the ratio of the currents passing through the electrodes. This differential signal is used for detection of the enzyme. Besides its differential signal output, the uniqueness of this sensor also lies on its label-free detection, expandable specificity spectrum by using aptamers specifically binding to other proteins and its capability of being integrated with CMOS circuitry and scaled down to improve sensitivity.