▎ 摘　　要

The intrinsic Raman signals provide the potential of graphene oxide (GO) for cellular imaging. Herein, novel surface-enhanced Raman scattering (SERS) labels based on GO-Ag nanoparticle (NP) composites are developed for fast cellular probing and imaging. The optimum SERS signals of the hybrids can be well controlled by adjusting the weight ratio between AgNO3 and GO. Utilizing GO-AgNPs as the highly sensitive optical probes, fast SERS imaging of cancer cells is realized with a very short integration time of about 0.06 s per pixel. Furthermore, folic acid (FA) is covalently conjugated to GO for targeting specific cancer cells with folate receptors (FRs). Targeted SERS images can be acquired after 2 h incubation with FA-GO-AgNPs, which are specifically located on the surface of FR-positive cancer cells. In conclusion, the GO-based Raman probes mentioned here open up exciting opportunities for biomedical imaging.