A highly sensitive and selective chemosensor for Pb²⁺ based on quinoline-coumarin.

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Lead (Pb2+) is a toxic heavy metal pollutant with significant environmental and health implications.
• Accurate and sensitive detection methods for Pb2+ are crucial for monitoring and remediation efforts.
• Fluorescent chemosensors offer advantages in sensitivity and selectivity for ion detection.

Purpose of the Study:

• To synthesize and characterize a novel fluorescent chemosensor for the selective detection of lead ions (Pb2+).
• To evaluate the sensing performance, including sensitivity, selectivity, and optimal detection conditions.

Main Methods:

• Synthesis of ethyl(E)-2-((2-((2-(7-(diethylamino)-2-oxo-2H-chromene-3-carbonyl)hydrazono)methyl)quinolin-8-yl)oxy)acetate (1).
• Characterization using spectroscopic techniques (1H NMR, 13C NMR) and mass spectrometry (ESI-MS).
• Fluorescence spectroscopy was employed to study the response to Pb2+ in a CH3CN/HEPES buffer medium.

Main Results:

• The synthesized sensor (1) exhibited a highly sensitive and selective "on-off" fluorescence response to Pb2+.
• A binding stoichiometry of 1:1 between the sensor and Pb2+ was established.
• The sensor demonstrated a low detection limit of 0.5 μM for Pb2+ within a stable pH range of 4 to 8.

Conclusions:

• The developed fluorescent chemosensor provides a promising tool for the sensitive and selective detection of lead ions.
• The sensor's performance characteristics make it suitable for potential applications in environmental monitoring and biological sample analysis.
• Further research could explore its application in real-world sample matrices.