Quartz crystal microbalance (QCM) biosensor was used for the chiral recognition of five pairs of enantiomers by using goat serum albumin (GSA) and rabbit serum albumin (RbSA) as chiral selectors. Serum albumin (SA) was immobilized on the QCM through the self-assembled monolayer technique, and the surface concentration of GSA and RbSA were 8.8 × 10(-12)   mol cm(-2) and 1.2 × 10(-11) mol cm(-2) , respectively. The QCM biosensors showed excellent sensitivity and selectivity. Meanwhile, the chiral recognition of SA sensors was quite species dependent. There were differences between GSA and RbSA sensors in the ability and the preference of chiral recognition. To R,S-1,2,3,4-tetrahydro-1-naphthylamine (R,S-1-TNA), R,S-1-(4-methoxyphenyl)ethylamine (R,S-4-MPEA), and R,S-1-(3-methoxyphenyl)ethylamine (R,S-3-MPEA), the preference of the stereoselective SA-drug binding of the two kinds of SA sensors were consistent. However, to R,S-2-octanol (R, S-2-OT) and R,S-methyl lactate (R,S-MEL), the two kinds of SA sensors had opposite chiral recognition preference. Moreover, the interactions of SA and the five pairs of enantiomers have been further investigated through ultraviolet (UV) and fluorescent (FL) spectra. The UV/FL results were in accordance with the consequence of QCM.

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The chiral discrimination studies of biological system are theoretically and practically significant for the development of chiral drugs and life science. Our work has embarked upon the interaction between serum albumin (SA) (including human SA and bovine SA), R,S-1-(4-methoxyphenyl)ethylamine, and R,S-1-(3-methoxyphenyl)ethylamine. The formation of intermediate transition state, binding sites, and chiral discrimination ability can be investigated by ultraviolet-visible spectra and fluorescence spectra. Moreover, both the changes of hydrophobic microenvironment and energy transfer can be detected by synchronous fluorescence spectra and fluorescence lifetime.