LAUSR

L-Methionine (L-Met) is an essential amino acid for the human body. The detection of L-Met in water solution is very important. Herein, we report an efficient approach for the fluorescent detection of L-Met with high selectivity and sensitivity in water using a cationic pillar[5]arene-based chemosensor (AWP5). When various L-amino acids are added to the AWP5 water solution, only L-Met can induce fluorescence in AWP5 at λem = 520 nm, showing dramatic enhancement; thus, other amino acid do not interfere in the L-Met recognition process. AWP5 also shows high sensitivity for L-Met in water, with the lowest detection limit of AWP5 for L-Met being 5.46 × 10−7 mol L−1.