Campus Units

Biochemistry, Biophysics and Molecular Biology, Mechanical Engineering

Document Type

Article

Publication Version

Published Version

Publication Date

2011

Journal or Book Title

Langmuir

Volume

27

Issue

23

First Page

14696

Last Page

14702

DOI

10.1021/la202067y

Abstract

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 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.

Comments

Reprinted (adapted) with permission from Langmuir, 2011, 27 (23), pp 14696–14702, doi:10.1021/la202067y. Copyright 2011 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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