Immobilization of Gold Nanoparticles onto Silicon Surfaces by Si−C Covalent Bonds

A series of ω-alkene-1-thiol-stabilized gold nanoparticles were prepared by a wet process and then covalently linked to a hydrogen-terminated silicon(111) surface with Si−C bonds via a thermal hydrosilylation reaction. The modified silicon surfaces were observed mainly by high-resolution scanning electron microscopy (HR-SEM). The HR-SEM images revealed that the gold nanoparticles protected with 2-propene-1-thiol (C3) were covalently bound to the hydrogen-terminated silicon surface, after which the nanoparticles self-fused; on the other hand, gold nanoparticles protected with 5-hexene-1-thiol (C6) or 10-undecene-1-thiol (C11) were linked to the hydrogen-terminated silicon surface independently. These surfaces were stable in air and can be stored for several months without detectable decomposition.