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

Optically active membranes were used as transducers to discriminate D-amino acids from L-amino acids. A noise-FFT (Fast Fourier Transform) technique was employed to measure the membrane impedance change due to different amino acid isomers. A flow method was used whereby the selection of amino acid samples was done automatically. Diastereomeric interactions (homochiral and heterochiral) occured between the membranes and amino acid isomers. These homochiral and heterochiral interactions differ sufficiently in the resultant arrangement of molecules at the surface of the membrane so as to permit the discrimination of D- from L-amino acids.