Aptamer Functionalized Microcantilever Sensors for Cocaine Detection

TitleAptamer Functionalized Microcantilever Sensors for Cocaine Detection
Publication TypeJournal Article
Year of Publication2011
AuthorsKang K, Sachan A, Nilsen-Hamilton M, Shrotriya P
Journal TitleLangmuir
Date Published12
ISBN Number0743-7463
Accession NumberWOS:000297427500092

A cocaine-specific aptamer was used as a receptor molecule in a microcantilever-based surface stress sensor for detection of cocaine molecules. An interferometric technique that relies on measuring differential displacement between two microcantilevers (a sensing/reference pair) was utilized to measure the cocaine/aptamer binding induced surface stress changes. Sensing experiments were performed for different concentrations of cocaine from 25 to 500 mu M in order to determine the sensor response as a function of cocaine concentration. In the lower concentration range from 25 to 100 mu M, 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 mu M, the surface stress values demonstrated a weaker dependence on the affinity complex surface coverage. On the basis of a sensitivity of 3 mN/m for the surface stress measurement, the lowest detectable threshold for the cocaine concentration is estimated to be 5 mu M. Sensing cantilevers could be regenerated and reused because of reversible thermal denaturation of aptamer.

URL<Go to ISI>://WOS:000297427500092