Single-Molecule Sensing of DNA Intercalating Drugs in Water

Area of Science:

• Environmental Science
• Biophysics
• Analytical Chemistry

Background:

• Pharmaceutical residues in surface water pose environmental risks.
• Sensitive and rapid water quality monitoring is essential for environmental protection.
• Single-molecule techniques like Tethered Particle Motion (TPM) offer high sensitivity.

Purpose of the Study:

• To investigate the potential of high throughput TPM (htTPM) for detecting DNA-intercalating drugs.
• To assess htTPM's capability in identifying pharmaceutical contaminants in aquatic environments.
• To determine if carbamazepine interacts with DNA via intercalation.

Main Methods:

• Utilized high throughput Tethered Particle Motion (htTPM), a single-molecule technique.
• Analyzed DNA conformational changes induced by potential intercalating agents.
• Tested known intercalators (YOYO-1, SYTOX orange, doxorubicin) and carbamazepine.
• Compared results in various aqueous buffer conditions.

Main Results:

• htTPM successfully detected DNA intercalation by YOYO-1, SYTOX orange, and doxorubicin.
• Carbamazepine was shown not to be a DNA intercalator, confirmed by htTPM and other techniques.
• Optimal buffer conditions for monitoring intercalation compounds using htTPM were identified.

Conclusions:

• htTPM is a viable method for detecting DNA-intercalating pharmaceutical residues in water.
• The study clarifies the interaction mechanism of carbamazepine with DNA.
• Optimized htTPM protocols can enhance environmental monitoring of water quality.