Positional Isomerism Influencing Differential Supramolecular Metallogelation: In Situ AgNP Formation and Heavy Metal
1Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
Langmuir : the ACS Journal of Surfaces and Colloids
|April 23, 2026
Summary
New pyridine-based receptors selectively form metallogels with silver and cadmium ions. One receptor enables visual detection of cadmium in water and forms silver nanoparticles for antibacterial applications.
Area of Science:
- Supramolecular Chemistry
- Materials Science
- Nanotechnology
Background:
- Adipic dihydrazide-based receptors are explored for metal ion complexation.
- Pyridine moiety functionalization influences receptor properties.
- Metallogelation is a promising self-assembly process for functional materials.
Purpose of the Study:
- To synthesize and investigate pyridine-functionalized adipic dihydrazide receptors.
- To study the effect of pyridine nitrogen position on metallogelation behavior.
- To explore applications in metal ion detection and silver nanoparticle formation.
Main Methods:
- Synthesis of four receptors: three pyridine-based and one phenyl-based control.
- Investigation of metallogelation with various metal ions (Ag+, Cd2+, etc.).
- Characterization of metallogel formation and properties.
- Application of metallogel for selective metal ion detection and silver nanoparticle synthesis.
Main Results:
- Receptors ADH-Py-p and ADH-Py-m showed selective metallogelation with Ag+ and Cd2+, respectively.
- Metallogel P-Ag-G formed with Ag+ facilitated in situ silver nanoparticle (AgNP) generation.
- The Cd2+-responsive metallogel ADH-Py-m enabled naked-eye detection of Cd2+ in real water samples.
- The P-Ag-G metallogel and its nanocomposite exhibited antibacterial activity.
Conclusions:
- Positional isomerism of the pyridine moiety significantly impacts metallogelation selectivity.
- Developed receptors offer a platform for selective metal ion sensing and functional nanomaterial fabrication.
- The study demonstrates a cost-effective method for detecting toxic heavy metals in environmental samples.
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