The invention relates to a surface-enhanced Raman technology based on
signal-off and used for detecting
intracellular telomerase activity. According to the technology,
graphene,
carbon nitride, MoS2, SiO2 and the like are taken as carriers, nano-gole or nano-silver with controllable dimension and morphology or a composite magnetic nano-particle with a core-shell structure is supported by the carriers, and then a hairpin probe containing a
telomerase primer and a Raman molecule
beacon is fixedly disposed on the nano=particle surface, so that the high-sensitivity high-selectivity SERS detection method based on
signal-off is established. When a target exists, the primer extends and generates
a DNA chain with a
repeat sequence under the effect of
telomerase, and the
DNA chain is hybridized with the probe molecule, then the
DNA hairpin structure is opened, a Raman
signal molecule with the single-chain labeled end is far away from a Raman substrate, the Raman signal is reduced, and high-sensitivity detection on telomerase is realized. The probe prepared by taking
Hela cervical carcinoma cell as a model realizes
intracellular telomerase
activity detection and dynamic detection on
intracellular telomerase activity variation under effect of a telomerase inhibiting medicament. By using multiple cells for imaging, the probe is confirmed to be capable of distinguishing
tumor cells and normal cells.