A new biosensor for chiral recognition using goat and rabbit serum albumin self-assembled quartz crystal microbalance.

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.

Self-assembly and chiral recognition of quartz crystal microbalance chiral sensor.

A novel chiral sensor based on the self-assembled monolayer of (6(A)-omega-mercaptoethylureado-6(A)-deoxy)heptakis(2,3-di-o-phenylcarbamoyl)-6(B), 6(C), 6(D), 6(E), 6(F), 6(G)-hexa-o-phenylcarbamoyl-beta-cyclodextrin (Ph-beta-CD-SH) on a quartz crystal transducer for chiral recognition was set up. (R,S)-(+/-)-(3-methoxyphenyl)ethylamine were recognized by this QCM chiral sensor with a QCM chiral discrimination factor of 1.33. Furthermore, UV spectroscopy was used to investigate the mechanism of host-guest interactions between (6(A)-azido-6(A)-deoxy)heptakis(2,3-di-o-phenylcarbamoyl)-6(B), 6(C), 6(D), 6(E), 6(F), 6(G)-hexa-o-phenylcarbamoyl-beta-cyclodextrin (Ph-beta-CD) and (R,S)-(+/-)-(3-methoxyphenyl) ethylamine. The UV discrimination factor was determined to be 0.066.

A novel strategy for rapid real-time chiral discrimination of enantiomers using serum albumin functionalized QCM biosensor.

A novel and effective method has been developed for chiral discrimination using a quartz crystal microbalance (QCM) biosensor with self-assembled bovine serum albumin (BSA) or human serum albumin (HSA). The successfully constructed QCM chiral biosensors exhibited rapid and real-time enantioselective recognition. The QCM chiral discrimination factor (alpha(QCM)) can be calculated through resonance frequency shifts in response to five pairs of enantiomers. Moreover, the interactions between these ten enantiomers and two serum albumins (SA) were investigated in detail by means of ultraviolet-visible (UV-vis) and fluorescence (FL) spectra. The results indicated that the discrimination ability were quite different between BSA and HSA. R,S-1-(3-Methoxyphenyl)ethylamine (R,S-3-MPEA) and R,S-1-(4-methoxyphenyl)ethylamine (R,S-4-MPEA) can be easily differentiated by the BSA sensor, while the selectivity of the HSA sensor for R,S-tetrahydronaphthylamine (R,S-TNA), R,S-2-octanol (R,S-2-OT) and R,S-methyl lactate (R,S-MEL) was higher than that of the BSA sensor. The UV and FL spectra indicated the formation of a complex between SA and enantiomers and strong fluorescence quenching through static quenching mechanism. The in-depth study demonstrated that the calculated UV/FL discrimination factors (alpha(UV) and alpha(FL)) were consistent with the QCM experimental results (alpha(QCM)).