Lipophilic Vitamin E Diffusion through Bicontinuous Microemulsions

Area of Science:

• Electrochemistry
• Materials Science
• Physical Chemistry

Background:

• Bicontinuous microemulsions (BMEs) are complex fluids with interconnected water and oil phases.
• Understanding solute diffusion within BMEs is crucial for applications in drug delivery and electrochemical sensing.
• Lipophilic molecules like vitamin E (VE) present unique diffusion challenges in microemulsion systems.

Purpose of the Study:

• To investigate the diffusion properties of vitamin E (VE) in bicontinuous microemulsions (BMEs).
• To determine the effect of varying water-to-oil phase ratios (W/O_BME) on VE diffusion.
• To explore the utility of optimized BMEs as electrolyte solutions for electrochemical measurements.

Main Methods:

• Electrochemical techniques, including voltammetry, were used to measure VE diffusion.
• Fluorescence correlation spectroscopy (FCS) was employed to independently assess diffusion dynamics.
• BMEs with different W/O_BME ratios were prepared and utilized as electrolyte solutions.

Main Results:

• An oil-rich BME (40/60 W/O_BME) significantly enhanced the current response of VE at a fluorinated nanocarbon electrode.
• Voltammetric and FCS measurements confirmed a higher diffusion coefficient for VE in oil-rich BMEs.
• The accelerated VE diffusion was attributed to the widened oil phase pathways in oil-rich BMEs, especially near the electrode interface.

Conclusions:

• Controlling BME composition, specifically favoring oil-rich formulations, effectively enhances lipophilic solute diffusion.
• Optimized BMEs serve as superior electrolyte solutions, improving electrochemical measurement sensitivity and performance.
• The findings highlight the potential of tailored BMEs for advanced electrochemical sensing applications.