A bifunctional coumarin-based CD probe for chiral analysis of amino acids in aqueous solution

Amino acids play important roles in human pathology and physiology and the qualitative and quantitative determination of chiral amino acids in humans and mammals also has important impacts on the life sciences. Therefore, the introduction of artificial probes to assess the concentrations and enantiomeric compositions [ee = ([D] - [L])/([D] + [L])] of amino acids in aqueous solution is necessary in understanding certain biological processes and diagnosing and treating diseases. Herein, a bifunctional achiral coumarin probe (Br-Coumarin) is reported to determine the absolute configuration, ee value, and concentration of 16 amino acids in THF/H₂O = 1/4 solution at micromolar concentrations. The effectiveness and practicability of the sensing methods are illustrated through the evaluation of various ee values and concentrations of Cys, Pro, and Phe samples with good accuracy. Besides, the reactions of the probe with various amino acids exhibit different colors under daylight or UV light (365 nm). Particularly, Br-Coumarin can be used to visually detect Cys, Lys, Arg, and Pro with high selectivity under both daylight and UV light (365 nm) and exhibits excellent selectivity and sensitivity for the fluorescent recognition of Cys.