A surfactant type fluorescence probe for detecting micellar growth

Area of Science:

• Colloid and Surface Chemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Surfactant aggregation into micelles is fundamental to many chemical and industrial processes.
• Directly probing micellar growth and structure changes remains a challenge.
• Novel fluorescent probes are needed to understand surfactant behavior.

Purpose of the Study:

• To develop and validate a novel fluorescent probe for detecting micellar growth.
• To investigate the sensitivity of the probe in different surfactant systems (anionic, cationic, catanionic).
• To enhance probe sensitivity in challenging systems using quenchers.

Main Methods:

• Synthesis and characterization of sodium 12-(N-dansyl)amino-dodecanate (12-DAN-ADA) as a tail-tethered fluorescent probe.
• Measurement of fluorescence anisotropy of 12-DAN-ADA in various surfactant solutions (CTAB, DEAB/SDS, SDS).
• Utilizing a water-soluble quencher to improve signal-to-noise ratio in specific systems.

Main Results:

• 12-DAN-ADA effectively detects micellar growth in catanionic and cationic (CTAB) surfactant systems.
• The probe shows high sensitivity in mixed oppositely charged surfactant systems (DEAB/SDS).
• Addition of a quencher significantly enhances sensitivity for like-charged SDS micellar systems.

Conclusions:

• 12-DAN-ADA is a versatile and sensitive fluorescent probe for studying micellar growth.
• The probe's fluorescence anisotropy provides direct insights into micelle formation and dynamics.
• This method offers a valuable tool for advancing surfactant science and related applications.