On-chip chiral separation based on bovine serum albumin-conjugated carbon nanotubes as stationary phase in a microchannel

A novel method of chiral separation based on protein‐stationary phase immobilized in a poly(methyl methacrylate) microfluidic chip was developed. BSA conjugated with the shortened carboxylic single‐walled carbon nanotubes (SWNTs) was employed as the chiral selector. Successful separation of tryptophan enantiomers was achieved in less than 70 s with a resolution factor of 1.35 utilizing a separation length of 32 mm. This is the first example of chiral separation based on SWNTs‐BSA conjugates as stationary phase immobilized in microchip channel. The stability of the stationary phase in the channel was examined by microchip electrophoresis with laser‐induced fluorescence detection. Factors that influenced the chiral separation resolution were examined. Under the optimized conditions, the proposed modified chip revealed adequate repeatability concerning run‐to‐run. These results show that the use of SWNTs‐BSA conjugates within microfluidic channels hold great promise for a variety of analytical schemes.