A rhodamine-based Hg2+ sensor with high selectivity and sensitivity in aqueous solution: a NS2-containing receptor

Area of Science:

• Chemical Sensing
• Materials Science
• Analytical Chemistry

Background:

• Mercury ions (Hg2+) pose significant environmental and health risks.
• Development of selective and sensitive sensors for Hg2+ detection is crucial.
• Rhodamine derivatives offer promising fluorescence properties for sensor applications.

Purpose of the Study:

• To design and synthesize a novel rhodamine-based sensor for selective Hg2+ detection.
• To evaluate the sensor's sensitivity and response mechanism.
• To investigate the binding mode between the sensor and Hg2+.

Main Methods:

• Synthesis of a rhodamine-based sensor incorporating a rhodamine fluorophore and an ionophore with high Hg2+ affinity.
• Characterization of the sensor's response to Hg2+ using colorimetric and fluorescence spectroscopy.
• Investigation of the binding mode using Nuclear Magnetic Resonance (1H NMR) and Electrospray Ionization Mass Spectrometry (ES+MS).

Main Results:

• The synthesized sensor demonstrated high selectivity and excellent sensitivity towards Hg2+.
• Sensor 1 exhibited dual-responsive behavior, enabling both colorimetric and fluorescent detection of Hg2+.
• Studies confirmed a 1:1 binding mode between the sensor and Hg2+.

Conclusions:

• A highly selective and sensitive dual-responsive sensor for Hg2+ detection has been successfully developed.
• The sensor provides a reliable method for detecting Hg2+ in aqueous buffer solutions.
• The findings contribute to the advancement of chemical sensing technologies for environmental monitoring.