Stereoselective Sensing of l- and d-Amino Acids: Development of a Fluorescence-Array Based on Readily Available Chiral Phosphoric Acids

The identification of structurally related analytes has become possible using sensor arrays, based on sets of cross-reactive chemosensors. This work reports the use of readily available chiral phosphoric acids for the array-based, chemo- and stereoselective sensing of l- and d-amino acids. Six bis- and trisphosphoric acids were used in combination with Ni2+ and Eu3+, resulting in a set of twelve chiral fluorescent chemosensors. This sensor-array enables a correct classification of l-amino acids with 100 % accuracy, while the differentiation between l- and d-amino acids can be achieved with 94 % accuracy. In addition, the systematic analysis of sensor contributions has allowed the use of a reduced set of seven sensors for the classification of l-amino acids, thus drastically reducing the amount of necessary measurements.