Sub-ppb mercury detection in real environmental samples with an improved rhodamine-based detection system

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Sensor Technology

Background:

• Accurate determination of mercury (Hg²⁺) ions in water is crucial for environmental safety.
• Existing methods may lack the required sensitivity or selectivity for complex environmental samples.
• Development of novel fluorescent sensors is needed for efficient mercury detection.

Purpose of the Study:

• To develop and optimize a Rhodamine-based fluorescent sensor for sensitive and selective Hg²⁺ determination.
• To adapt the sensor for practical application in environmental water samples.
• To achieve low detection limits and high selectivity in the presence of interfering metal ions.

Main Methods:

• Synthesis of a Rhodamine-based fluorescent sensor incorporating Rhodamine-6G.
• Optimization of experimental conditions, including buffer system (acetic acid at pH 5.25).
• Application of the optimized procedure using high-throughput microplates for water sample analysis.

Main Results:

• The optimized sensor demonstrated a low detection limit of 0.27 μg L^-1 for Hg²⁺.
• High selectivity was achieved in competitive experiments with realistic concentrations of other metal ions.
• Successful application to real-world samples, including tap and river waters, with good results.

Conclusions:

• The developed Rhodamine-based fluorescent sensor provides a sensitive and selective method for Hg²⁺ determination in environmental water.
• The optimized procedure is suitable for high-throughput analysis and reliable for monitoring mercury levels in tap and river water.
• This sensor represents a valuable tool for environmental mercury monitoring and water quality assessment.