Selective deposition of gold nanoparticles on SiO ₂ Si nanowires for molecule detection

The selective deposition of gold nanoparticles on the surface of N-(2-Aminoethy1)-3-aminopropy1-trimethoxysilane (AEAPTMS)-pretreated silicon nanowire (SiNW)s for molecule detection was demonstrated. The SiNWs were fabricated by scanning probe lithography (SPL) and tetramethyl ammonium hydroxide (TMAH) wet etching. The width and height of the SiNWs were 60 nm and 10 nm, respectively. The gold nanoparticles were synthesized by the chemical reduction method. The electronic properties of the SiNWs in response to the binding of different molecules on the surface of the SiNWs subsequently were discussed. A dynamic observation of the change in conductance was conducted to monitor the reaction between gold nanoparticles and the AEAPTMS-pretreated surface of the SiNWs. The reaction of gold nanoparticles on the surface of the SiNWs took about 750s before conductance saturation. Finally, an engineered enzyme, KSI-126C, with a thiol terminal was designed to bind with the gold nanoparticles on the surface of the SiNWs. Shifts in turn-on voltage in I-V _ds characteristics have clearly been observed after the binding of molecules and gold nanoparticles,