Covalent functionalization of NH2-MIL-101(Cr) with bovine serum albumin for enatioselectic separation of racemic 1-phenylethanol

The immobilization of bovine serum albumin (BSA) with high efficiency, good reproducibility and stability for chiral separation has attracted much attention in the medicinal field. BSA was immobilized into MIL-101(Cr) by three ways for efficient chiral separation in this research. MIL-101(Cr)@BSA was firstly prepared by adsorption, NH 2 -MIL-101(Cr) ⊂ BSA by direct bonding, and NH 2 -MIL-101(Cr) ⊂ Glu ⊂ BSA by glutaraldehyde crosslinking bonding. Compared to the other two materials, NH 2 -MIL-101(Cr) ⊂ BSA as a new enantioselective separator, with the most BSA loading rate of 437.6 mg g −1 exhibited excellent chiral separation performances and succeeded in realizing a complete chiral separation of racemic 1–phenylethanol within 14 s. It was found that the NH 2 -MIL-101(Cr) ⊂ BSA was more strongly bound to R -1-phenylethanol and the ee value could reach 100 % when the material was added in three batches. The different interactions between BSA and racemates mainly including hydrogen bonding, hydrophobic interaction and π-π interaction were revealed by the molecular docking studies, especially hydrogen bonding, accounting for the observed selective chiral recognition capacity of racemic 1–phenylethanol of NH 2 -MIL-101(Cr) ⊂ BSA. Moreover, both of NH 2 -MIL-101(Cr) ⊂ BSA and NH 2 -MIL-101(Cr) ⊂ Glu ⊂ BSA showed excellent stability and reusability. This combination of theory and experiment provided a clearer basis for other researchers to have different requirements for protein immobilization, and provided new ideas and methods for the development of chiral selectors.