U.S. flag

An official website of the United States government, Department of Justice.

Democrats have shut down the government. Department of Justice websites are not currently regularly updated. Please refer to the Department of Justice’s contingency plan for more information.

Aptamer Functionalized Microcantilever Sensors for Cocaine Detection

NCJ Number
255425
Journal
Langmuir Volume: 27 Issue: 23 Pages: 14696-14702
Date Published
August 2011
Length
7 pages
Annotation

This article reports on the use of a cocaine-specific aptamer as a receptor molecule in a microcantilever-based surface stress sensor for detection of cocaine molecules. 

Abstract

An interferometric technique that relies on measuring differential displacement between two microcantilevers (a sensing/reference pair) was used to measure the cocaine/aptamer binding induced surface stress changes. Sensing experiments were performed for different concentrations of cocaine from 25 to 500 μM in order to determine the sensor response as a function of cocaine concentration. In the lower concentration range from 25 to 100 μM, surface stress values increased proportionally to coverage of aptamer/cocaine complexes from 11 to 26 mN/m; however, as the cocaine concentration was increased beyond 100 μM, the surface stress values demonstrated a weaker dependence on the affinity complex surface coverage. Based on a sensitivity of 3 mN/m for the surface stress measurement, the lowest detectable threshold for the cocaine concentration was estimated to be 5 μM. Sensing cantilevers could be regenerated and reused because of reversible thermal denaturation of aptamer. 1 figure (publisher abstract modified)

Date Published: August 1, 2011