Functionalized alkoxysilane mediated controlled synthesis of noble metal nanoparticles dispersible in aqueous and non-aqueous medium.

The synthesis of amphiphilic noble metal nanoparticles involving the functional role of 3-aminopropyltrimethoxysilane (3-APTMS) and 3-glycidoxypropyltrimethoxy-silane (3-GPTMS) is reported herein. The mechanistic approach on the reactivity of these functional alkoxysilane for the typical controlled synthesis of AuNPs as evidenced from UV-visible spectroscopy and transmission electron microscopy (TEM) is reported. The experimental findings demonstrate the followings; (1) Methanolic solution of 3-GPTMS undergo interaction with 3-APTMS and the same is facilitated in the presence of 3-APTMS treated noble metal ions, (2) The molar ratio of 3-GPTMS/3-APTMS control the nanogeometry as well as the dispersibility of AuNPs in both aqueous and non-aqueous media, (3) the dispersion ability of nanoparticles is found to be based on the hydrophobic alkyl chain of the reaction product of 3-GPTMS and 3-APTMS, and (4) AuNPs shows absorption maxima as a function of polarity and refractive index of the medium. A typical application of as synthesized AuNPs as peroxidase mimetic is reported.