“…The fluorescence titration of amino acid against BP@Eu-TCPP was tested with a similar method. 32 In brief, BP@Eu-TCPP (100 μg/mL) was prepared in water. Pyruvic acid (Pyr), sodium lactate (Lac), caffeic acid (Caf), tyrosine (Tyr), L-cysteine (L-Cys), glycine (Gly), L-proline (L-Pro), histidine (His), L-lysine (L-Lys), and L-Arg were dissolved in water at a determined concentration, respectively.…”