Dual-state dual emission from precise chemically engineered bi-ligand MOF free from encapsulation and functionalization with self-calibration model for visual detection

• Published in: Mikrochimica acta (1966) Vol. 191; no. 1; p. 62
• Main Authors: Ameen, Sameera Sh. Mohammed, Qader, Idrees B., Qader, Hemn A., Algethami, Faisal K., Abdulkhair, Babiker Y., Omer, Khalid M.
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.01.2024; Springer Nature B.V
• Subjects: Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Emission spectra; Encapsulation; Folic acid; Ligands; Metal-organic frameworks; Microengineering; Nanochemistry; Nanotechnology; Onsite; Original Paper; Self calibration; Stability analysis; Metal organic framework; Ratiometric fluorescence; Dual-state emission; Dual-emission; Visual detection; Bi-ligand MOFs; Folic acid
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-023-06148-5

Synthesis of dual-state dual emitting metal–organic frameworks (DSDE-MOFs) is uncommon and challenging. Additionally, DSDE-MOFs can fulfil the expanding need for on-site detection due to their stability and self-reference for a variety of non-analyte variables. In the present work, a novel intrinsic DSDE of chemically engineered bi-ligand Eu-based MOF (UoZ-1) was designed. The prepared UoZ-1 spherical particles were small-sized around 10–12 nm and displayed blue (425 nm) and red fluorescence (620 nm) at both states, dispersed in liquid and in solid state, when excited at 250 nm. A ratiometry platform was developed since the red emission was quenched by the addition of folic acid and the blue emission was almost remained unaffected. In the fluorometric ratiometric-mode, a dynamic linear range was recorded from 10 to 200 µM with LOD about 0.4 µM. Visual-based detection with assistance of smartphone was developed for quantification based on RGB analysis using Color Grab App. In the visual-mode, LOD as small as 2.3 µM was recorded. By utilizing the intrinsic dual-emitting UoZ-1, highly stable, recyclable, sensitive, and selective on-site visual detection of folic acid can be achieved. UoZ-1, a DSDE-MOF with no encapsulation or functionalization requirements, exhibits great potential for diverse applications. Graphical abstract