A DNA duplex-based, tailor-made fluorescent sensor for porphyrin derivatives

Area of Science:

• Supramolecular Chemistry
• Molecular Sensing
• Biotechnology

Background:

• Hydrophobic guest molecules are challenging to detect using conventional sensors.
• Fluorescent sensors offer high sensitivity for molecular detection.
• DNA hybridization can be utilized for signal amplification and molecular recognition.

Purpose of the Study:

• To synthesize a DNA-based fluorescent sensor capable of detecting hydrophobic guest molecules.
• To investigate the mechanism of host-guest binding-induced DNA hybridization and fluorescence signaling.
• To demonstrate the sensor's ability to switch emission from monomer to excimer upon guest binding.

Main Methods:

• Synthesis of a trifunctional sensor molecule incorporating per-O-methylated beta-cyclodextrin (per-Me-beta-CD), DNA, and pyrene.
• Utilizing per-Me-beta-CD as the host for hydrophobic guest binding.
• Monitoring fluorescence emission changes (monomer vs. excimer) of pyrene upon porphyrin derivative addition.

Main Results:

• The synthesized sensor successfully detected hydrophobic guest molecules, specifically a porphyrin derivative.
• Host-guest binding between per-Me-beta-CD and the guest molecule promoted DNA hybridization.
• This DNA hybridization event led to a measurable change in fluorescence from monomer to excimer emission.

Conclusions:

• A novel DNA-based fluorescent sensor for hydrophobic molecules was successfully developed.
• The sensor's mechanism relies on host-guest binding to trigger DNA hybridization and fluorescence signal switching.
• This approach provides a sensitive platform for detecting hydrophobic guests through fluorescence modulation.