Preparation of D-NCCDs and its application in fluorescent/colorimetric dual-mode discrimination of glutamine enantiomers

Abstract

The chiral recognition of glutamine (Gln) enantiomers is of great importance in medicine, disease diagnosis, drug analysis, and food analysis. Up to now, there are few reports on the detection of Gln enantiomers based on fluorescent and colorimetric dual mode. Therefore, the design of a dual-mode probe combining fluorescence and colorimetry for the detection of Gln enantiomers needs further exploration and research. In this work, a new type of CDs (D-NCCDs) was designed and synthesized. In the presence of hydrogen peroxide, the fluorescence of D-NCCDs gradually decreased as the concentration of D-glutamine increased, the ratio of fluorescence intensity (F/F0) shows a good linear relationship with the concentration of D-glutamine within the range of 0.5–10 mM, with a detection limit of 0.11 mM. Additionally, the color of the solution gradually changed from light yellow to yellow-brown. But the fluorescence and absorbance of D-NCCDs did not change significantly after different concentrations of L-glutamine were added. Thus dual-mode discrimination of glutamine enantiomers through fluorescence and colorimetry was achieved.