Selective deposition of gold nanoparticles on SiO ₂ /Si nanowire

We demonstrate selective deposition of citrate-passivated gold nanoparticles onto silicon dioxide patterns. Further, selective deposition of gold nanoparticles on the oxides, generated by scanning probe lithography (SPL), surface of silicon nanowire is achieved. Main methodology is to form H-terminated silicon surface and hydroxyl group on SiO₂ sample surface, then link amino function group only on SiO₂ surface by self-assembly mechanism. N-(2-Aminoethyl)-3-aminopropyl-trimethoxysilane (AEAPTMS) pretreated sample was immersed in the gold colloidal solution such that the NH₂ group become protonated forming NH³⁺. The NH³⁺ groups provide a negative charge bindable environment for citrate-passivated gold nanoparticles. Impact on different AEAPTMS dilute solvents is also investigated for the performance of selective deposition of gold nanoparticles. It is found that H-terminated sample surface effectively eliminated nonspecific reaction during silanization such that microscale or nanoscale selective deposition of gold nanoparticles is obtainable. The proposed method can be applied in both nanoelectronics and nanobiosensors.