Recognition of Hg(2+) using diametrically disubstituted cyclam unit.

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biotechnology

Background:

• Mercury (Hg(2+)) is a toxic heavy metal pollutant.
• Detection of Hg(2+) in biological samples is crucial.
• Existing detection methods may lack sensitivity or specificity.

Purpose of the Study:

• To develop a novel sensor for selective Hg(2+) detection.
• To enhance the sensor's properties using beta-cyclodextrin (β-CD).
• To evaluate the sensor's applicability in biological systems.

Main Methods:

• Synthesis of a 1,4,8,11-tetraazacyclotetradecane derivative (L) with a diazo reporter.
• Formation of an inclusion complex (L·2β-CD) to improve water solubility.
• Visual colorimetric detection of Hg(2+) binding.
• Toxicity assessment using Pseudomonas putida.
• Application as a staining agent for intracellular Hg(2+) detection.

Main Results:

• The synthesized ligand (L) selectively binds Hg(2+) with a visible color change.
• The L·2β-CD complex exhibits enhanced water solubility and a more intense color response to Hg(2+).
• The ligand (L) demonstrated low toxicity to Pseudomonas putida.
• The L·2β-CD system was successfully used to stain and detect intracellular Hg(2+) in the bacteria.

Conclusions:

• A novel, visually detectable Hg(2+) sensor based on a tetraazacyclotetradecane derivative has been developed.
• Complexation with β-CD significantly improves the sensor's performance in aqueous media.
• The developed sensor is non-toxic and suitable for detecting Hg(2+) in microorganisms, offering potential for environmental and biological monitoring.