Efficient detection of a biomarker for infant jaundice by a europium()-organic framework luminescence sensor

• Published in: RSC advances 2019-11, Vol.9 (64), p.37584-37593
• Main Authors: Xu, Ping, Yang, Han-Wen, Shi, Jia-Li, Ding, Bo, Zhao, Xiao-Jun, Yang, En-Cui
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Biomarkers; Chemical sensors; Chemical synthesis; Chemistry; Crystallography; Electron transfer; Emission spectra; Europium; Fluorescence; Format; Infrared spectroscopy; Ligands; Organic chemistry; T shape; Time dependence; Urine
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c9ra08604h

Efficient detection of excess bilirubin in human serum and urine is highly important for the early diagnosis of infant jaundice. A highly stable Eu( iii )-based microporous framework with bent {Eu(COO)} chains interconnected by pairs of T-shaped 4,4′-(4,4′-bipyridine-2,6-diyl)dibenzoate (bpydb 2− ) linkers, {[Eu(H 2 O)(HCOO)(bpydb)]·solvent} n ( 1 ), was solvothermally synthesized and used as a chemical sensor for bilirubin response under clinically-applicable visible-light excitation. Due to the significant synergetic effect of the inner filter effect and photoinduced electron transfer, 1 can effectively probe trace amounts of bilirubin in aqueous solution through fluorescence decay with a strong quenching constant of 6.40 × 10 4 M −1 and low detection limit of 1.75 μM. More importantly, a portable test paper made from 1 was further developed to achieve qualitative, naked-eye visualized differentiation for the biomarker in clinical applications. These interesting findings highlight the importance of the π-conjugated antenna ligand for clinically applicable Ln-MOF sensors. A Eu( iii )-MOF sensor with intense red luminescence can effectively probe bilirubin in water through fluorescence decay, and can be fabricated into portable test papers to achieve visualized detection of bilirubin.