There are methods used to test the optical purity of enantiomers; however,
most of the simple methods are not precise and more complicated methods are
better. As a result, these methods cannot be widely used for industrial pu
rposes. The aim of this research is to design a sensor which can discrimina
te D-amino acids from L-amino acids. The designed sensor has chiral membran
es and uses the technique of impedance change of these chiral membranes to
discriminate the amino acids. We used a noise-FFT (Fast Fourier Transform)
technique to determine the membrane impedance. When an enantiomer membrane
resides in a chiral environment, (E*), diastereomeric interactions (E*-D) a
nd (E*-L) are created, which may differ sufficiently in the arrangement of
molecules of the membranes so as to permit the discrimination of optical su
bstances due to the change in membrane characteristics. With increasing con
centrations of the amino acids, the membrane resistance changes depended on
the optical activity of the amino acids. The results suggest that the impe
dance changes of the chiral membrane with diastereomeric reaction can be us
ed for the high-performance chemical sensor to measure the optical purity o
f different substances.