High-selectivity turn-on fluorescence-based fluoride ion detection using histidine-functionalized UiO-66-NH₂

Area of Science:

• Materials Science
• Analytical Chemistry
• Environmental Science

Background:

• Fluoride ions are crucial in drinking water but can be harmful at high concentrations.
• Developing selective and sensitive sensors for fluoride detection is essential for water quality monitoring.
• Metal-organic frameworks (MOFs) offer tunable properties for sensing applications.

Purpose of the Study:

• To synthesize and characterize a novel Hisditine-functionalized UiO-66-NH2 (UiO-66-NH2@Hst) fluorescent probe.
• To evaluate the probe's performance for detecting fluoride ions in aqueous media.
• To investigate the sensing mechanism and assess its suitability for real-world applications.

Main Methods:

• Solvothermal synthesis of Hisditine-functionalized UiO-66-NH2.
• Fluorescence spectroscopy for fluoride ion detection.
• Stability and selectivity tests against various ions and pH conditions.
• Determination of the limit of detection (LoD).

Main Results:

• UiO-66-NH2@Hst demonstrated a
• turn-on
• fluorescence response for fluoride ions, optimal in water.
• The probe exhibited high selectivity and stability for fluoride ions across a pH range of 3-10.
• A low limit of detection (LoD) of 0.013 ppm was achieved, well below WHO guidelines.

Conclusions:

• UiO-66-NH2@Hst is a promising candidate for a highly selective and sensitive fluorescence-based sensor for fluoride ions.
• The hydrogen bond formation mechanism contributes to the observed fluorescence enhancement.
• The sensor's performance makes it suitable for monitoring fluoride levels in drinking water.