Silicon Nanowires-based Probes for Surface-enhanced Raman Spectroscopy

Surface-enhanced Raman spectroscopy (SERS) is a powerful technique that can enable single-molecule detection and identification. Despite the first report of SERS being some thirty years ago, it is widely recognized that SERS has not yet reached its full potential as applications are primarily hampered by poor repeatability and lack of consistent and optimized substrates. Current understanding of SERS suggests that the main phenomena involved are (i) electromagnetic enhancement caused by the collective response of electrons in low-dimension metals (plasmon resonances), and (ii) chemical enhancement associated with chemical interactions between the molecule and the metal surface. Recent results by the research group have revealed that silicon nanowires (SiNWs) are excellent quasi 1D templates to fabricate SERS probes based on silver nanoclusters embedded on the surface of SiNWs, indicating potential additional mechanisms of SERS enhancement. This project seeks to understand the origin of the observed ultra-high sensitivity SERS in SiNWs-based probes, and to exploit and optimize its use as reliable and efficient probes for SERS. Such SiNWs-based probes are expected to gain from the vast experience in the large-scale integration semiconductor industry for applications such as biological sensors to enable the realization of lab on a chip.