Engineering 2,4,6-Triaminopyrimidine-Functionalized Fumed Silica for Highly Selective Hg²⁺ Detection: Spectroscopic...

Area of Science:

• Materials Science
• Environmental Chemistry
• Analytical Chemistry

Background:

• Mercury (Hg²⁺) ions are highly toxic, persistent, and bioaccumulative pollutants.
• Their presence in the environment poses a significant threat to human health.
• Developing sensitive and selective chemosensors for Hg²⁺ detection is crucial.

Purpose of the Study:

• To synthesize and characterize a new hybrid material, fumed-Si-Pr-TAP, for Hg²⁺ ion detection.
• To evaluate the sensing performance of the material in terms of selectivity and detection limit.
• To investigate the molecular-level interactions between the material and Hg²⁺ ions using computational methods.

Main Methods:

• Stepwise functionalization of fumed-silica with 3-(chloropropyl)trimethoxysilane and 2,4,6-triaminopyrimidine (TAP).
• Comprehensive characterization using FT-IR, TGA, N₂ adsorption-desorption, SEM, and EDX.
• Sensing studies in ethanolic media and Density Functional Theory (DFT) calculations.

Main Results:

• The fumed-Si-Pr-TAP material demonstrated good selectivity for Hg²⁺ ions.
• An acceptable detection limit of 3 × 10^-7 M was achieved.
• DFT calculations confirmed nitrogen-rich TAP moieties as efficient binding sites for Hg²⁺, with a reduced HOMO-LUMO gap indicating enhanced reactivity.

Conclusions:

• The developed fumed-Si-Pr-TAP hybrid material is a promising candidate for advanced chemosensor applications for Hg²⁺ detection.
• The nitrogen-rich TAP functional groups are key to the material's high sensitivity and selectivity.
• The study provides molecular insights into the sensing mechanism, supporting the design of future chemosensors.