Target-triggered Au NPs self-assembled for fluorescence-SERS dual-mode monitoring of telomerase in living cells and in vivo

Telomerase was regarded as a pivotal tumor marker for cancers diagnosis and prognosis evaluation. Hence, the accurate quantification detection and distribution information of telomerase in complex biological environment is undoubtedly very important. Herein, we developed a dual-mode strategy for telomerase detection which combined the advantages of both surface-enhanced Raman scattering (SERS) and fluorescence approaches. The nanoprobes, consists of Au NPs and specific nucleic acid probes, would be triggered by telomerase to generate electromagnetic hot spots enhanced Au dimers for telomerase fluorescence imaging and label-free Raman detection after entering the living cells. In addition, a stronger fluorescent signal was generated after two signal amplifications. With the help of ATP and catalytic hairpin assembly (CHA), more Au dimers will be generated to increase the Raman signal. The experimental results showed that the dual-mode nanoprobe has great selectivity and sensitivity to telomerase and could distinguish different kinds of tumor cells by in situ imaging. Limit of detection (LOD) was 7.76 HeLa cells for fluorescence detection and 2.98 Hela cells fore SERS detection. This nanoplatform would be a promising dual-mode diagnostic strategy for biomarkers in complex biological environment.