Related Experiment Video
Updated: Jun 23, 2026
07:54
Fluorescence Recovery after Merging a Droplet to Measure the Two-dimensional Diffusion of a Phospholipid Monolayer
Published on: October 15, 2015
Surfactant-induced fluorescence changes in fluorescein dye
A K Mathur1, C Agarwal, B S Pangtey
1Industrial Toxicology Research Centre, P.B. No. 80, M. G. Marg, Lucknow-226001, India.
International Journal of Cosmetic Science
|May 22, 2009
Summary
Surfactants alter fluorescein dye properties. Non-ionic and anionic surfactants cause distinct spectral shifts and intensity changes, while cationic surfactants show complex concentration-dependent effects due to micelle interactions.
Area of Science:
- Photochemistry
- Physical Chemistry
- Colloid and Surface Chemistry
Background:
- Fluorescein dyes are widely used as fluorescent probes.
- Surfactants form micelles that can interact with dye molecules.
- The spectral properties of dyes can be sensitive to their microenvironment.
Purpose of the Study:
- To investigate the effect of different types of surfactants (non-ionic, anionic, cationic) on the spectral characteristics (absorbance and fluorescence) of fluorescein dyes.
- To understand the interaction mechanisms between surfactant micelles and fluorescein dye molecules.
Main Methods:
- Spectrophotometric analysis of fluorescein dye solutions with varying concentrations of non-ionic, anionic, and cationic surfactants.
- Fluorometric analysis to measure fluorescence intensity and spectral shifts.
- Analysis of absorbance maxima (Δmax) and intensity changes.
Main Results:
- Non-ionic surfactants caused a hypsochromic shift (shorter wavelengths) and decreased absorbance.
- Anionic surfactants induced a bathochromic shift (longer wavelengths) with enhanced absorbance and fluorescence.
- Cationic surfactants exhibited concentration-dependent effects: initial decrease then increase in absorbance, and initial increase then decrease in fluorescence.
Conclusions:
- Surfactant micelles significantly alter the spectral properties of fluorescein dyes.
- The observed changes are attributed to the interaction between surfactant micelles and dye molecules, influencing the equilibrium between the colored quinoid and colorless lactone forms of the dye.
