Sensitive Ratiometric Detection of Vitamin B₂ by a Zn(II)-MOF with Tetranuclear Clusters.

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Vitamin B2 (VB2) is crucial for human health, necessitating efficient detection methods.
• Existing VB2 sensors often lack selectivity or sensitivity for real-world applications.
• Metal-organic frameworks (MOFs) offer tunable properties for advanced sensing platforms.

Purpose of the Study:

• To develop a highly efficient ratiometric fluorescent sensor for Vitamin B2 (VB2) detection.
• To utilize a novel Zn(II)-MOF for selective and sensitive VB2 quantification.
• To explore the application of the developed sensor in food and pharmaceutical samples.

Main Methods:

• Synthesis and characterization of a 2-fold interpenetrated Zn(II)-MOF (MOF 1) based on a 1,2-bis(benzimidazol-1-ylmethyl)benzene ligand.
• Ratiometric fluorescence detection of VB2 by observing changes in emission wavelengths (409 nm and 537 nm).
• Investigation of the sensing mechanism using PXRD, IR, UV-vis, fluorescence lifetimes, XPS, and theoretical calculations.
• Development of a smartphone-assisted visual detection method.

Main Results:

• MOF 1 exhibited selective ratiometric fluorescence detection of VB2 in aqueous media with a low limit of detection (0.11 μM).
• The sensor demonstrated high recovery rates (93.5-103.8%) when applied to real samples like milk and VB2 tablets.
• A smartphone-based RGB method was successfully developed for visual VB2 detection.

Conclusions:

• The developed Zn(II)-MOF serves as an effective on-off ratiometric fluorescent sensor for VB2.
• The sensor exhibits excellent selectivity, sensitivity, and applicability in food and pharmaceutical analysis.
• This work presents a promising approach for practical VB2 monitoring.