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Fabrication of Electrochemical-DNA Biosensors for the Reagentless Detection of Nucleic Acids, Proteins and Small Molecules
Published on: June 1, 2011
Aptamer sensor for cocaine using minor groove binder based energy transfer
Jinwen Zhou1, Amanda V Ellis, Hilton Kobus
1School of Chemical and Physical Sciences, Flinders University, Adelaide, SA 5001, Australia.
Analytica Chimica Acta
|February 21, 2012
Summary
We developed an optical aptamer sensor for detecting cocaine. This sensor utilizes a conformational change in DNA aptamers and energy transfer to report cocaine presence with a 0.2 μM detection limit.
Area of Science:
- Biomedical Engineering
- Analytical Chemistry
- Molecular Biology
Background:
- Cocaine detection is crucial for clinical diagnostics and forensic applications.
- Existing detection methods often lack sensitivity, specificity, or portability.
- Development of rapid, sensitive, and field-deployable cocaine sensors is needed.
Purpose of the Study:
- To develop and characterize a novel optical aptamer sensor for cocaine detection.
- To investigate the mechanism of signal generation based on DNA conformational changes and energy transfer.
- To demonstrate the feasibility of immobilizing the sensor on a surface for potential microfluidic applications.
Main Methods:
- Utilized a fluorescein isothiocyanate (FITC)-labeled DNA aptamer sensitive to cocaine.
- Induced aptamer conformational change from hairpin to T-junction upon cocaine binding.
- Employed Hoechst 33342 (DNA minor groove binder) for Förster resonance energy transfer (FRET) initiation.
- Implemented minor groove binder based energy transfer (MBET) for signal reporting.
- Covalently immobilized DNA aptamers on carboxy-functionalized polydimethylsiloxane (PDMS) surfaces.
Main Results:
- The aptamer sensor exhibited a conformational change in the presence of cocaine.
- Minor groove binder based energy transfer (MBET) was successfully initiated, reporting cocaine presence.
- Achieved a low detection limit of 0.2 μM for cocaine.
- Demonstrated successful surface immobilization of DNA aptamers on PDMS for potential microfluidic integration.
Conclusions:
- The developed optical aptamer sensor offers a sensitive and specific method for cocaine detection.
- The MBET mechanism provides a robust platform for signal transduction in aptamer-based sensors.
- Surface immobilization of the sensor is a critical step towards developing integrated microfluidic devices for cocaine analysis.
