A ratiometric lanthanide-free fluorescent probe based on two-dimensional metal-organic frameworks and carbon dots for the determination of anthrax biomarker

• Published in: Mikrochimica acta (1966) Vol. 188; no. 3; p. 84
• Main Authors: Bao, Jian, Mei, Jie, Cheng, Xia, Ren, Dandan, Xu, Guanhong, Wei, Fangdi, Sun, Yong, Hu, Qin, Cen, Yao
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.03.2021; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Anthrax; Bacillus anthracis - chemistry; Biological effects; Biological properties; Biomarkers; Biomarkers - blood; Carbon - chemistry; Carbon dots; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Fluorescence; Fluorescent Dyes - chemistry; Fluorescent indicators; Humans; Limit of Detection; Metal-organic frameworks; Metal-Organic Frameworks - chemistry; Metalloporphyrins - chemistry; Microengineering; Nanochemistry; Nanotechnology; Original Paper; Picolinic Acids - blood; Povidone; Quantum Dots - chemistry; Rare earth metals; Reference signals; Self calibration; Spectrometry, Fluorescence; Two dimensional materials; Zinc compounds; Dipicolinic acid; Ratiometric fluorescence; Carbon dots; 2D metal-organic frameworks; Anthrax biomarker
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-021-04701-8

A lanthanide-free fluorescent probe has been constructed for the first time based on two-dimensional metal-organic frameworks (2D MOFs) and carbon dots (CDs) for ratiometric determination of dipicolinic acid (DPA), the biomarker of Bacillus anthracis . The fluorescence intensity at 659 nm increased due to the release of organic ligands TCPP resulting from the selective interaction between DPA and Zn 2+ of 2D MOFs. CDs provided a reference signal at 445 nm which was almost unaffected, realizing self-calibration DPA sensing. F 659 /F 445 versus the concentration of DPA shows good linear relationships in the range 0.01–0.2 μM and 0.2–10 μM under 390-nm excitation, with a detection limit of 7 nM. The ratiometric probe was prepared from 2D lanthanide-free MOFs so that the drawbacks of lanthanide-based probes were overcome. The proposed sensing system was successfully applied to the determination of DPA in spiked biological samples. These results suggest that a novel, simple, and selective strategy of determining DPA with 2D lanthanide-free MOFs is implemented. Graphical abstract Zn-TCPP nanosheets and a blue carbon dots (b-CDs) are synthesized to construct the ratiometric probe, which can exhibit fluorescence at 445and 659 nm with 390-nm excitation. Dipicolinic acid (DPA) can deprive the junction ions of Zn-TCPP nanosheets, triggering the collapse ofZn-TCPP nanosheets. The fluorescence at 659 nm is enhanced due to the release of TCPP, while the peak of b-CDs at 445 nm is almost not affected. Thus, the fluorescence intensity ratio (F 659 /F 445 ) can serve as the response signal for sensitive DPA sensing.