Smartphone-based colorimetric determination of fluoride anions using polymethacrylate optode

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Fluoride anion determination is crucial for drinking water quality control.
• Existing methods for fluoride detection can be time-consuming or require complex equipment.

Purpose of the Study:

• To develop a novel, transparent polymer optode for the digital colorimetric determination of fluoride anions.
• To create a user-friendly and rapid method for fluoride analysis in water samples.

Main Methods:

• Immobilization of a zirconium(IV)-alizarin red complex within a polymethacrylate matrix.
• Development of a digital image processing algorithm for colorimetric analysis using the RGB color-coordinate system.
• Validation of the optode's analytical performance, including linearity and detection limits.

Main Results:

• The polymer optode exhibits a distinct color change from purple to yellow upon contact with fluoride anions.
• The developed method demonstrates a linearity range of 0.1–30 mg·L⁻¹ for fluoride determination.
• A low detection limit of 0.03 mg·L⁻¹ was achieved, indicating high sensitivity.

Conclusions:

• The modified polymethacrylate-based optode serves as a ready-to-use colorimetric system for fluoride analysis.
• This method offers rapid and reliable results, making it suitable for on-site drinking water quality monitoring.
• The digital colorimetric approach simplifies fluoride determination compared to traditional spectrophotometric techniques.