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Photosensitive surfactants: micellization and interaction with DNA
Yuriy Zakrevskyy1, Julian Roxlau1, Gerald Brezesinski2
1Experimental Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany.
The Journal of Chemical Physics
|February 12, 2015
Summary
Light-responsive surfactants self-assemble and interact with DNA. Azobenzene-containing surfactants show aggregation forces significantly impacting micellization, controllable by light exposure.
Area of Science:
- Physical Chemistry
- Supramolecular Chemistry
- Materials Science
Background:
- Photosensitive surfactants offer light-controllable interactions with biomolecules.
- Understanding surfactant self-assembly and polyelectrolyte complexation is crucial for advanced materials.
Purpose of the Study:
- To investigate the self-assembly of photosensitive surfactants.
- To explore the interactions between these surfactants and DNA.
- To determine thermodynamic parameters of micellization and aggregation.
Main Methods:
- Calorimetric methods (e.g., determining standard micellization enthalpy, entropy, and Gibbs energy).
- Spectroscopic methods (UV-visible spectroscopy for aggregation onset and CMC estimation).
- Titration UV-visible spectroscopy to study DNA-surfactant complexation (CAC, precipitation, stabilization).
Main Results:
- Aggregation forces of photosensitive azobenzene units significantly contribute to micellization enthalpy.
- Critical micelle concentration (CMC) and thermodynamic parameters were determined under varying ionic strengths and temperatures.
- UV-visible spectroscopy effectively tracks aggregation onset and estimates CMC.
- DNA-surfactant interactions, including critical aggregation concentration (CAC), were characterized.
Conclusions:
- Photosensitive surfactants exhibit light-tunable self-assembly and interactions with DNA.
- The azobenzene moiety plays a key role in the micellization process.
- UV-visible spectroscopy provides a sensitive method for CMC determination and studying complex formation.
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