Discrimination of D-amino acids from L-amino acids using membrane impedance change

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.