Optical sensor for fluoride determination in tea sample based on evanescent-wave interaction and fiber-optic...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Optical Sensing

Background:

• Fluoride determination in consumables like tea is crucial for public health.
• Existing methods for fluoride analysis can be time-consuming or require complex equipment.
• Optical sensing offers a promising avenue for rapid and sensitive chemical detection.

Purpose of the Study:

• To develop a miniaturized optical sensor for accurate fluoride determination in tea samples.
• To evaluate the public health risks associated with fluoride levels in tea.
• To establish a versatile platform for detecting other hazardous species using evanescent-wave technology.

Main Methods:

• Development of a miniaturized optical sensor integrated onto an optical fiber.
• Utilization of evanescent-wave interaction for colorimetric fluoride detection at 575nm.
• Application of Beer's law for quantitative fluoride analysis.

Main Results:

• The sensor demonstrated a small detection volume (1.2μL) and fast analysis time (0.41min).
• Achieved a wide linear range (0.01-1.4mgL^-1) and a low detection limit (3.5μgL^-1).
• Exhibited excellent repeatability (2.34%) and was validated against conventional spectrophotometry and ion chromatography.

Conclusions:

• The developed optical sensor is effective for sensitive and accurate fluoride determination in tea.
• The sensor provides a valuable tool for assessing fluorosis risks in public health.
• The evanescent-wave based platform is adaptable for monitoring other hazardous substances.