Preparation of SiO₂@Au nanorod array as novel surface enhanced Raman substrate for trace pollutants detection

An effective surface enhanced Raman scattering (SERS) substrate is designed and fabricated by synthesis of SiO₂ nanorods array via glancing angle deposition, followed by coating Au nanoparticles onto SiO₂ surface in order to create numerous “hot spots”. The detecting sensitivity of such substrate could be optimized by simply adjusting the deposition time of Au. Thus, it can be used for detection of Rhodamine 6G at concentration as low as 10^-9 M. Furthermore, our SERS substrate is applied to detect 5 μg/g polychlorinated biphenyls in soil sample, which proves its potential for trace environmental pollutants detection.