A fluorescence turn-on sensor for iodide based on a thymine-Hg(II)-thymine complex.

Area of Science:

• Analytical Chemistry
• Biochemistry
• Materials Science

Background:

• Iodide is crucial for thyroid function and neurological activity.
• Accurate iodide detection is vital for food, pharmaceuticals, and biological samples.
• Existing methods for iodide detection may lack sensitivity or selectivity.

Purpose of the Study:

• To develop a rapid, sensitive, and selective fluorescence turn-on sensor for iodide detection.
• To utilize a thymine-mercury(II) complex for iodide sensing.
• To demonstrate the sensor's applicability in real-world samples like urine.

Main Methods:

• Synthesis of a fluorescent anthracene-thymine dyad (An-T).
• Formation of a An-T-Hg(II)-T-An complex that initially quenches fluorescence.
• Exploitation of iodide's stronger binding with mercury(II) to displace it, restoring fluorescence.

Main Results:

• The An-T-Hg(II)-T-An complex acts as a fluorescence turn-on sensor for iodide.
• Achieved a low detection limit of 126 nM for iodide.
• Demonstrated high selectivity for iodide over other common anions.
• Successfully applied the sensor to detect iodide in drinking water and urine samples.

Conclusions:

• The developed sensor provides a novel and facile strategy for sensitive and selective iodide detection.
• The fluorescence turn-on mechanism based on competitive binding is effective.
• This approach offers potential for sensing other anions and broadens analytical applications.