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Sequence-specific DNA detection at 10 fM by electromechanical signal transduction
Leyla Esfandiari1, Michael Lorenzini, Gayane Kocharyan
1Department of Bioengineering, University of California, Los Angeles , Los Angeles, California 90095, United States.
Analytical Chemistry
|September 10, 2014
Summary
This study presents a simple, PCR-free method for detecting DNA fragments down to 10 femtomolar. Longer DNA targets, like those found in bacterial 16S rRNA, improve detection limits for this sensitive nucleic acid platform.
Area of Science:
- Biotechnology
- Biosensing
- Molecular Diagnostics
Background:
- A rapid, sensitive, and cost-effective nucleic acid detection platform is crucial for various applications.
- Previous work introduced a low-cost device for sequence-specific nucleic acid detection using conductance changes.
Purpose of the Study:
- To demonstrate the operation of the nucleic acid detection device with longer DNA targets.
- To improve the limit of detection (LOD) for nucleic acid detection.
- To assess the device's potential for detecting clinically relevant bacterial sequences.
Main Methods:
- Utilized a PCR-free, optics-free approach based on electromechanical signal transduction.
- Employed a device measuring conductance changes of a pore blocked by bead-(peptide nucleic acid probe) conjugates.
- Investigated the detection of DNA oligomers of varying lengths (110, 235, 419, and 1613 nucleotides) at concentrations from 1 pM to 1 fM.
Main Results:
- The limit of detection (LOD) decreased as DNA target length increased.
- Oligomers of 419 and 1613 nucleotides were detectable down to 10 fM.
- No false positive responses were observed with noncomplementary DNA fragments.
Conclusions:
- The developed platform demonstrates improved sensitivity for longer DNA targets.
- The device's ability to detect 1613-base DNA oligomers suggests potential for detecting pathogenic bacteria via 16S rRNA.
- This technology offers a promising route for rapid, cost-effective nucleic acid detection.
