Near-IR Fluorescent Recognition of Arginine: High Chemoselectivity and Enantioselectivity Promoted by La³

The first near IR fluorescent probe for the chemoselective and enantioselective recognition of arginine in aqueous solution is reported in this work. This probe, made of a 1,1'-binaphthyl-based chiral aldehyde unit and a rhodamine-based near IR chromophore, in combination with La³⁺ exhibits highly chemoselective as well as enantioselective fluorescent enhancement with arginine at λ=764 nm upon excitation at λ=690 nm. Little or no fluorescent response is observed toward the chirality miss-matched arginine enantiomer or other common amino acids and their enantiomers. This probe also allows visual discrimination of the arginine enantiomers because of its fast and distinct color change upon interaction with the substrate.