Abstract
The fabrication of two-dimensional, covalent bond-mediated assembly of gold nanoparticles on glass substrates is reported herein. Highly monodispersed gold nanoparticles protected by mixed monolayers comprising of decanethiol (DT) and 11-mercapto-1-undecanol (MUO) are covalently immobilized on isocyanate-bearing layers on glass substrates through carbamate-forming reaction. Specifically, two-dimensional structures of these immobilized gold nanoparticles depend on the surface monolayer coverage of MUO molecules attached on the nanoparticles. The lower coverage allows formation of ordered two-dimensional superlattice, whereas increase in the MUO coverage induces disordered assembly and sometimes domain structures, as indicated by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The reason for this can be due to a steric effect and a significant change in the hydrophobicity of protective mono layers associated with interaction between immobilized gold nanoparticles.
