Micellar affinity gradient focusing in a microfluidic chip with integrated bilinear temperature gradients

Area of Science:

• Analytical Chemistry
• Microfluidics
• Separation Science

Background:

• Micellar affinity gradient focusing (MAGF) integrates micellar electrokinetic chromatography (MEKC) and temperature gradient focusing.
• MAGF separates analytes based on electrophoretic mobility and micellar phase partitioning.
• Analyte interaction strength with micelles is modulated by a temperature gradient.

Purpose of the Study:

• To develop and evaluate a bilinear temperature gradient for MAGF.
• To improve separation performance compared to linear temperature gradients.
• To fabricate a microfluidic chip capable of generating precise temperature profiles.

Main Methods:

• Fabrication of a hybrid PDMS/glass microfluidic chip with integrated microheaters.
• Implementation of a bilinear temperature gradient along the separation channel.
• Characterization of separation performance using fluorescent dyes and pI markers with SDS and poly-SUS surfactants.

Main Results:

• The bilinear temperature gradient design significantly improves separation performance.
• Nearly two times improvement in peak capacity and resolution was observed compared to linear gradients.
• Successful separation of various analytes including fluorescent dyes and pI markers was achieved.

Conclusions:

• A bilinear temperature gradient enhances MAGF performance in microfluidic systems.
• The developed microfluidic chip effectively generates the required temperature profiles.
• This advanced MAGF technique offers superior resolution and peak capacity for complex separations.