DNA-length-dependent fluorescent sensing based on energy transfer in self-assembled multilayers.

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Fluorescence resonance energy transfer (FRET) is a powerful tool for studying molecular interactions.
• Developing sensitive and selective DNA detection methods is crucial for diagnostics and research.
• Self-assembled multilayers offer a versatile platform for constructing biosensors.

Purpose of the Study:

• To construct a novel DNA-length-dependent fluorescent sensor.
• To utilize fluorescence resonance energy transfer (FRET) for DNA detection.
• To investigate the use of ZnO@CdS quantum dots and graphene oxide in a FRET-based sensor.

Main Methods:

• Fabrication of self-assembled multilayers: Quartz/GO/PDDA/Tx-DNA/PDDA/ZnO@CdS.
• Utilizing ZnO@CdS as the energy donor and graphene oxide (GO) as the energy acceptor.
• Employing single-stranded DNA (Tx-DNA) and poly(diallyldimethylammonium) chloride (PDDA) as linkers.
• Detecting complementary DNA (Px-DNA) by monitoring changes in FRET efficiency and fluorescence quenching.

Main Results:

• The sensor demonstrated DNA-length-dependent fluorescence quenching.
• The formation of double-stranded DNA altered the distance between the donor (ZnO@CdS) and acceptor (GO).
• Enhanced FRET efficiency led to a measurable change in the fluorescence of ZnO@CdS quantum dots.

Conclusions:

• A novel DNA-length-dependent fluorescent sensor was successfully constructed.
• The sensor effectively detects different DNA sequence lengths through FRET-based fluorescence quenching.
• This approach offers a promising method for sensitive DNA detection.