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Fiber-optic DNA sensor for fluorometric nucleic acid determination
P A Piunno1, U J Krull, R H Hudson
1Chemical Sensors Group, Department of Chemistry, Erindale College, Univerity of Toronto, Ontario, Canada.
Analytical Chemistry
|August 1, 1995
Summary
Researchers developed a novel optical DNA biosensor using synthesized single-stranded deoxyribonucleic acid (ssDNA) on quartz optical fibers. This regenerable biosensor detects complementary DNA (cDNA) and RNA (cRNA) with high sensitivity and a low detection limit.
Area of Science:
- Biotechnology
- Biosensor Technology
- Nucleic Acid Chemistry
Background:
- Development of sensitive and specific biosensors is crucial for molecular diagnostics.
- Optical detection methods offer non-invasive and real-time monitoring capabilities.
- Immobilization of nucleic acids on solid supports is key for creating stable biosensing platforms.
Purpose of the Study:
- To create a novel optical DNA biosensor utilizing immobilized single-stranded deoxyribonucleic acid (ssDNA) on quartz optical fibers.
- To evaluate the performance of the biosensor in terms of hybridization efficiency, sensitivity, and regenerability.
- To demonstrate the potential of the biosensor for detecting complementary nucleic acid sequences.
Main Methods:
- Synthesis of thymidylic acid icosanucleotides (dT20) on derivatized quartz optical fibers using automated solid-phase synthesis.
- Hybridization assays with complementary ssDNA (cDNA) and ssRNA (cRNA) in solution.
- Detection of hybridization using the fluorescent DNA stain ethidium bromide (EB).
- Characterization of hybridization extent using UV absorbance thermal denaturation studies.
Main Results:
- The optical DNA biosensor demonstrated successful hybridization with complementary nucleic acid targets.
- A detection limit of 86 ng/mL cDNA and a sensitivity of 200% fluorescence increase per 100 ng/mL cDNA were achieved.
- The biosensor proved to be regenerable for at least five cycles and stable after 1 year of storage, harsh washing, and autoclaving.
- Thermal denaturation studies confirmed the involvement of all 20 bases in duplex formation.
Conclusions:
- The developed optical DNA biosensor based on immobilized ssDNA on quartz fibers is a sensitive, specific, and robust platform.
- The biosensor is regenerable and stable, making it suitable for repeated use and long-term applications.
- This technology holds promise for various applications in molecular diagnostics and nucleic acid detection.