In-Situ covalent synthesis of gold nanorods on GO surface as ultrasensitive Raman probe

In this paper, using thiolated graphene oxide (GO-O-SH) as substrate, gold nanorods (AuNRs) covalently linked to the GO surface by in-situ seed growth method were first reported. The as-prepared composites were characterized by UV–vis spectrum, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Experimental results indicated that the introduction of short flexible organic chain between GO and AuNRs contributed to the homogenous synthesis of gold rods, and uniform gold nanorods with aspect ratio within 3~8 were covalently linked to the surface of GO with high stability and yield. The strategy represented an outstanding improvement in comparison to the traditional route for fabricating GO@AuNRs composites. Furthermore, based on coupling of the two nanomaterials, the composites could act as high sensitive Raman probe with limit of detection (LOD) reaching 1 × 10 −12 M.