Rapid Intracellular Growth of Gold Nanostructures Assisted by Functionalized Graphene Oxide and Its Application for Surface-Enhanced Raman Spectroscopy

Hybridization of metal nanoparticles with graphene oxide for high performance surface-enhanced Raman scattering (SERS) has attracted overwhelming attention in recent years. Herein, a one-pot green route for intracellular synthesis of gold nanostructures assisted by poly(vinylpyrrolidone) (PVP)-functionalized graphene oxide (GO) was proposed. The hybrids obtained [GO/PVP/intracellularly grown gold nanoparticles (IGAuNs)] randomly scattered throughout the cell. Compared with the IGAuNs, the growth of GO/PVP/IGAuNs was remarkably accelerated, which could be attributed to the coordination of PVP enriched on GO. GO/PVP/IGAuNs could serve as excellent SERS probes for ultrasensitive detection of cellular components of cancer cells located in the cytoplasm, nucleoplasm, and nucleolus. The random intracellular distribution of GO/PVP/IGAuNs facilitated the effective Raman characterization of cellular components, which was confirmed by the uniform distribution of SERS signals in the Raman image. The SERS signals induced by GO/PVP/IGAuNs could be collected as early as 15 h, which allowed rapid detection of tumor cells. In conclusion, this facile and green strategy for fast intracellular growth of GO/PVP/IGAuNs offered great potential for biomedical applications.