A Metal-Organic Framework as Selectivity Regulator for Fe³⁺ and Ascorbic Acid Detection

Area of Science:

• Materials Science
• Analytical Chemistry
• Biomedical Engineering

Background:

• Ferric ion (Fe3+) is crucial for cellular functions, but its detection faces challenges with rhodamine B (RhB) due to poor selectivity and photostability.
• Developing robust biosensors for Fe3+ and other biomolecules like ascorbic acid is essential for understanding cellular homeostasis and disease states.

Purpose of the Study:

• To design and synthesize a novel "on-off-on" fluorescent switching nanoprobe for highly sensitive and selective detection of Fe3+ and ascorbic acid.
• To overcome the limitations of traditional detection methods by enhancing selectivity and photostability.

Main Methods:

• A facile one-pot synthesis was employed to create a rhodamine B embedded within a metal-organic framework (RhB@MOF) nanocomposite.
• The RhB@MOF nanoprobe utilized the inner filter effect (IFE) and photoinduced electron transfer (PET) mechanisms for analyte detection.
• The probe's performance was evaluated for detecting Fe3+ in human serum and ascorbic acid in rat brain microdialysate.

Main Results:

• The RhB@MOF nanoprobe demonstrated enhanced photostability and fluorescence lifetime compared to free RhB.
• Ultrasensitive and selective detection of Fe3+ was achieved, with minimal interference from other substances.
• The probe successfully detected ascorbic acid in biological samples, validating its practical applicability.

Conclusions:

• The rationally designed RhB@MOF nanoprobe offers a promising platform for the selective and sensitive detection of Fe3+ and ascorbic acid.
• This work provides valuable insights into the development of metal-organic framework-based biosensors for complex biological systems.
• The "on-off-on" fluorescent switching mechanism enhances detection capabilities for critical biomolecules.