Aminopyrazole-Based Ligand Induces Gold Nanoparticle Formation and Remains Available for Heavy Metal Ions Sensing. A Simple “Mix and Detect” Approach

A novel way to synthesize gold nanoparticles based on the use of N-alkylaminopyrazole is shown. This ligand has a triple functionality: induces AuNPs formation, stabilizes the formed nanoparticles, and even remains available for an external coordination with heavy metal ions. The availability of N-alkylaminopyrazole ligands onto the AuNPs surface is studied using UV−vis and NMR techniques. The mechanism of formation of AuNPs along with the synthesis optimization and characterization are studied using voltammetry and UV−vis, and the results are discussed in detail. The application of N-alkylaminopyrazole-derived gold nanoparticles in the heavy metal ions sensing is also tested showing a high sensitivity for mercury detection at low concentration level. The functionalization of metal nanoparticles with these receptors followed by heavy metal ions detection represents a simple "mix and detect" approach with interest for several other sensing applications.