Fluorescence and surface-enhanced Raman scattering dual-mode nanoprobe for monitoring telomerase activity in living cells

The in situ assay of telomerase activity is important for cancer diagnosis. Herein, a dual-mode functional nanosensor based on fluorescence and surface-enhanced Raman scattering (SERS) was proposed for telomerase activity monitoring. The as-prepared biosensor features Cy5-functional Au nanoparticles (NPs) as the dual functional nanoprobe. The telomerase substrate primer extended under the action of telomerase to form the telomere repeats, and the hairpin DNA loop was opened during hybridization. The distance between the signaling molecule Cy5 and Au NPs changed, resulting in a decrease and a recovery of the SERS and fluorescence signal, respectively. The results showed that the fluorescence and SERS intensity both depended on the telomerase activity and could be used for sensing purposes. On this basis, in situ fluorescence combined with Raman imaging permitted real-time analysis of changes in the telomerase activity of human cells, and hence the approach could be applied for screening of anticancer drugs.