Multifunctional fluorescent sensors N/CDs@Eu-MOFs for rapid detection of childhood obesity and acute myeloid leukemia biomarkers and identification of chiral enantiomers of lysine.

BACKGROUND: Amino acids are essential components of proteins and enzymes and play a vital role in biological systems. Abnormal concentrations of amino acids in organisms can significantly disrupt normal physiological functions. Glycine (Gly) and l-lysine (L-Lys) have been identified as biomarkers for childhood obesity and acute myeloid leukemia (AML), respectively, so their sensitive detection is very crucial for human health.

RESULTS: In this study, a novel fluorescent sensing material, N/CDs@Eu-MOF, was developed by integrating N-doped carbon dots (N/CDs) with rare earth metal-organic frameworks (Eu-MOFs). This composite functions as a ratiometric fluorescent probe to detect biomarkers (Gly, L-Lys) associated with childhood obesity and acute myeloid leukemia. The detection limits are 0.86 μM and 0.12 μM, respectively. Notably, the fluorescent probe N/CDs@Eu-MOF is able to efficiently distinguish the enantiomers of Lys. Specifically, L-Lys induces a substantial enhancement of the N/CDs characteristic peak, whereas D-Lys exhibits minimal impact on the fluorescence emission. Additionally, the N/CDs@Eu-MOF also has been applied in ratiometric fluorescence imaging of Gly and L-Lys levels in living cells, and can be employed as a sensitive and non-invasive tool to measure the levels of Gly and L-Lys in living cells.

SIGNIFICANCE: This study provided an innovative approach for the quantitative evaluation of lysine and the chiral identification of lysine enantiomers. Meanwhile, the constructed fluorescent sensors were proved to be beneficial for the early detection and clinical evaluation of childhood obesity and AML-M2 disease.