Aptamer Functionalized Microcantilever Sensors for Cocaine DetectionLangmuir
Publication VersionPublished Version
AbstractA 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 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. 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 μM. Sensing cantilevers could be regenerated and reused because of reversible thermal denaturation of aptamer.
Copyright OwnerAmerican Chemical Society
Citation InformationKyungho Kang, Ashish Sachan, Marit Nilsen-Hamilton and Pranav Shrotriya. "Aptamer Functionalized Microcantilever Sensors for Cocaine Detection" Langmuir Vol. 27 Iss. 23 (2011) p. 14696 - 14702
Available at: http://works.bepress.com/marit-nilsen-hamilton/9/