Fluoride Binding Potential of Selected Phytochemicals: A Pilot Study.

Area of Science:

• Environmental Science
• Biochemistry
• Analytical Chemistry

Background:

• Fluoride (F⁻) contamination in drinking water poses a significant global health risk, particularly in regions like India and China.
• Chronic exposure to elevated fluoride levels (above 1.5 ppm) can cause irreversible fluorosis (F⁻ toxicity), with no effective cure.
• Conventional defluoridation methods exist, but adsorption using plant-derived compounds is a promising approach for F⁻ removal and mitigating toxicity.

Purpose of the Study:

• To investigate the binding interactions between selected phytochemicals and fluoride ions (F⁻).
• To evaluate the potential of these phytochemicals as electrochemical biosensors for F⁻ detection.
• To determine the binding constants and detection limits of phytochemical-F⁻ interactions.

Main Methods:

• UV-visible spectroscopy and emission techniques were employed to study the binding of phytochemicals with F⁻.
• Benesi-Hildebrand (BH) plots were used to calculate binding constants and detection limits for various phytochemical-F⁻ mixtures.
• Proton nuclear magnetic resonance (¹H-NMR) titration experiments were conducted to confirm binding characteristics.

Main Results:

• Calculated binding constants for phytochemicals ranged from 1.5 × 10³ M⁻¹ (PCA) to 34.9 × 10³ M⁻¹ (CUR).
• Detection limits for F⁻ varied among phytochemicals, with CUR showing a limit of 1.54 × 10⁻⁷ M and PCA at 5.8 × 10⁻⁶ M.
• Binding characteristics were further validated using ¹H-NMR titration, confirming the interactions.

Conclusions:

• Phytochemicals demonstrate significant potential as effective binding agents for fluoride ions (F⁻).
• These findings suggest that phytochemicals can reduce fluoride bioavailability, offering a natural strategy for water defluoridation.
• The study highlights the utility of phytochemicals in both F⁻ removal and as components in electrochemical biosensing applications.