Microfluidics for chiral separation of biomolecules

Microfluidic techniques including capillary electrophoresis (CE), capillary electrochromatography (CEC), micellar electrokinetic capillary chromatography (MEKC) have been applied to the chiral separation of a large number of biomolecules such as amino acids, peptides, and neurotransmitters. For CEC, the chiral separation is carried out into capillaries containing chiral selector (CS)-bonded stationary phase, while for CE, the CS is added to the mobile phase, which is moved by an electroosmotic flow (EOF). Chiral surfactants and/or CS are usually involved in pseudostationary phases of MEKC. The microfluidic techniques can offer some advantages over conventional techniques, e.g., high selectivity, excellent separation efficiency, and low cost. In this review, innovations covering detection systems, separation mechanism, CS, and chiral analytes of biomolecules are discussed. The most applied CSs and the chiral separation of representative biomolecules are discussed in detail. Finally prospects and future developments of microfluidics for chiral separation are also proposed.