Open tubular CEC in a microfluidic chip for rapid chiral recognition

Area of Science:

• Analytical Chemistry
• Separation Science
• Chiral Separations

Background:

• Chiral recognition is crucial in pharmaceuticals and biochemistry.
• Microfluidic capillary electrophoresis offers rapid and efficient separation techniques.

Purpose of the Study:

• To demonstrate chiral recognition of dansyl amino acids using microfluidic open tubular capillary electrophoresis (muOTCEC).
• To investigate the role of avidin as a chiral selector immobilized on a microchannel wall.
• To optimize separation conditions for enhanced chiral resolution.

Main Methods:

• Microfluidic open tubular capillary electrophoresis (muOTCEC) with fluorescence detection.
• Immobilization of avidin as a chiral stationary phase (CSP) on the microchannel wall via physical adsorption.
• Characterization of CSP using field emission scanning electron microscopy (FESEM).
• Investigation of buffer pH and methanol concentration as critical separation parameters.

Main Results:

• Avidin was homogenously distributed on the microchannel surface.
• Buffer pH significantly influenced avidin adsorption due to electrostatic interactions.
• Methanol concentration modulated hydrophobic interactions, impacting separation quality.
• Successful separation of four dansyl racemic amino acids within 100 seconds with high resolutions (up to 3.01).

Conclusions:

• muOTCEC with immobilized avidin is a highly effective method for rapid chiral recognition of amino acid enantiomers.
• Optimization of buffer pH and organic modifier content is key for achieving efficient separations.
• This technique shows promise as a valuable tool for chiral analysis in microfluidic systems.