Graphene oxide mediated surface-enhanced Raman scattering substrate: Well-suspending and label-free detecting for protein

This study reports a Graphene Oxide Mediated SERS (GOMS) Substrate supporting silver nanoparticles (AgNPs), which is characterized with the relatively clean surface of nanoparticles and formation of stable suspension in the detection. Moreover the tight anchoring of silver nanoparticles on the platform by a multiple oxygen-containing groups on GO carbon grid favors for the generation of large number of “hot” spots. We demonstrate that anchoring of the 4-mercaptopyridine (4-Mpy) analyte at these system leads to a pronounced intensification of its Raman emission using described SERS assay. Most impressively, acting as a new type of SERS substrate, the GOMS Substrate can disperse well in water during the detection process, which makes the Raman signals very uniform. This work not only shows that target molecule such as 4-Mpy has a strong interaction with the nanoparticle surface can be detected quickly and accurately with high sensitivity and stability, but also show SERS activity successfully for Bovine Serum Albumin (BSA), which interaction with nanoparticle surface is weak, in about physiological saline of Label-free detection. The results reported herein may lead to many applications in SERS techniques.