Gold nanoparticle embedded silicon nanowire biosensor for applications of label-free DNA detection

Gold nanoparticle (GN) embedded silicon nanowire (SiNW) configuration was proposed as a new biosensor for label-free DNA detection to enhance the sensitivity. The electric current flow between two terminals, a source and a drain electrode, were measured to sense the immobilization of probe oligonucleotides and their hybridization with target oligonucleotides. The complementary target oligonucleotide, breast cancer DNA with 1 pM, was sensed. In addition, its sensing mechanism and limit of detection (LOD) enhancement was investigated through simulation. The results support that the LOD can be improved by reducing the SiNW doping concentration. This emerging architecture combined nanostructure of spherical GN and SiNW has high potential as a label-free biosensor due to its facile fabrication process, high thermal stability, immobilization efficiency with a thiol-group in a self-assembled monolayer (SAM), and improved sensitivity. (C) 2010 Elsevier B.V. All rights reserved.