Potentiometric sensing of chiral amino acids

Recognition of enantiomers of amino acids was achieved with potentiometric measurements using chiral sensors constructed by a surface imprinting technique. The sensors exhibited recognition properties toward one isomer of racemic N-carbobenzoxy-aspartic acids (N-CBZ-Asp) without any preseparation processes. The sensors translated the enantioselective recognition event into a potential change by detecting optically active N-CBZ-Asp in a concentration range of 5.0 x 10(-6)-1.2 x 10(-2) M. The enantiomeric selectivity coefficients of the sensors for the counter isomers were in the range of 4.0 x 10(-3)-9.0 x 10(-3). The sensitivity of these sensors is assigned to the specific surface modification of the electrodes resulting in chiral recognition and to the coupled transduction activity of the sensor.